diff --git a/src/command_runner.rs b/src/command_runner.rs
index 0b73422..268bff7 100644
--- a/src/command_runner.rs
+++ b/src/command_runner.rs
@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::error::Error;
 use std::ffi::OsStr;
 use std::io::{Result as IoResult, Write};
@@ -5,53 +6,40 @@ use std::process::Command;
 use std::process::Output;
 use std::process::Stdio;
 
+#[macro_export]
+macro_rules! args {
+    ($($x:expr),*) => (
+        &[$($x.as_ref()),*]
+    );
+    ($($x:expr,)*) => (args![$($x),*]) // handle trailing commas
+}
+
 pub trait CommandRunner {
-  fn run_with_args_and_stdin<S: AsRef<OsStr> + ?Sized>(
+  fn run_with_args_and_stdin(
     &self,
     program: &str,
-    args: &[&S],
+    args: &[&OsStr],
     stdin: &str,
   ) -> IoResult<Output>;
-  fn run_with_args<S: AsRef<OsStr> + ?Sized>(
-    &self,
-    program: &str,
-    args: &[&S],
-  ) -> IoResult<Output> {
+  fn run_with_args(&self, program: &str, args: &[&OsStr]) -> IoResult<Output> {
     self.run_with_args_and_stdin(program, args, "")
   }
-  fn get_output<S: AsRef<OsStr> + ?Sized>(
-    &self,
-    program: &str,
-    args: &[&S],
-  ) -> Result<Vec<u8>, Box<dyn Error>> {
+  fn get_output(&self, program: &str, args: &[&OsStr]) -> Result<Vec<u8>, Box<dyn Error>> {
     let output = self.run_with_args(program, args)?;
     if !output.status.success() {
       return Err(String::from_utf8(output.stderr)?.into());
     }
     Ok(output.stdout)
   }
-  fn get_stderr<S: AsRef<OsStr> + ?Sized>(
-    &self,
-    program: &str,
-    args: &[&S],
-  ) -> Result<Vec<u8>, Box<dyn Error>> {
+  fn get_stderr(&self, program: &str, args: &[&OsStr]) -> Result<Vec<u8>, Box<dyn Error>> {
     let output = self.run_with_args(program, args)?;
     if !output.status.success() {
       return Err(String::from_utf8(output.stderr)?.into());
     }
     Ok(output.stderr)
   }
-  fn run_successfully<S: AsRef<OsStr> + ?Sized>(
-    &self,
-    program: &str,
-    args: &[&S],
-  ) -> Result<(), Box<dyn Error>> {
-    let output = self.run_with_args(program, args)?;
-    if output.status.success() {
-      Ok(())
-    } else {
-      Err(String::from_utf8(output.stderr)?.into())
-    }
+  fn run_successfully(&self, program: &str, args: &[&OsStr]) -> Result<(), Box<dyn Error>> {
+    self.get_output(program, args).map(|_| ())
   }
 }
 
@@ -59,10 +47,10 @@ pub trait CommandRunner {
 pub struct StdCommandRunner;
 
 impl CommandRunner for StdCommandRunner {
-  fn run_with_args_and_stdin<S: AsRef<OsStr> + ?Sized>(
+  fn run_with_args_and_stdin(
     &self,
     program: &str,
-    args: &[&S],
+    args: &[&OsStr],
     input: &str,
   ) -> IoResult<Output> {
     // FIXME: logger
@@ -90,14 +78,14 @@ where
   C: 'a + CommandRunner,
 {
   command_runner: &'a C,
-  user_name: &'a str,
+  user_name: Cow<'a, str>,
 }
 
 impl<'a, C> SetuidCommandRunner<'a, C>
 where
   C: 'a + CommandRunner,
 {
-  pub fn new(user_name: &'a str, command_runner: &'a C) -> SetuidCommandRunner<'a, C> {
+  pub fn new(user_name: Cow<'a, str>, command_runner: &'a C) -> SetuidCommandRunner<'a, C> {
     SetuidCommandRunner {
       command_runner,
       user_name,
@@ -138,13 +126,13 @@ impl<'a, C> CommandRunner for SetuidCommandRunner<'a, C>
 where
   C: 'a + CommandRunner,
 {
-  fn run_with_args_and_stdin<S: AsRef<OsStr> + ?Sized>(
+  fn run_with_args_and_stdin(
     &self,
     program: &str,
-    args: &[&S],
+    args: &[&OsStr],
     input: &str,
   ) -> IoResult<Output> {
-    let uid = get_user_by_name(self.user_name)
+    let uid = get_user_by_name(&self.user_name)
       .expect("User does not exist")
       .uid();
     let set_home = TempSetEnv::new("HOME", format!("/home/{}", self.user_name));
@@ -196,10 +184,10 @@ impl<'a, C> CommandRunner for SuCommandRunner<'a, C>
 where
   C: 'a + CommandRunner,
 {
-  fn run_with_args_and_stdin<S: AsRef<OsStr> + ?Sized>(
+  fn run_with_args_and_stdin(
     &self,
     program: &str,
-    args: &[&S],
+    args: &[&OsStr],
     input: &str,
   ) -> IoResult<Output> {
     let raw_new_args = [self.user_name, "-s", "/usr/bin/env", "--", program];
diff --git a/src/factory.rs b/src/factory.rs
index 5b3eea6..1aedea2 100644
--- a/src/factory.rs
+++ b/src/factory.rs
@@ -82,7 +82,7 @@ impl<'a, C: CommandRunner> SymbolRepository<'a>
             Box::new(Dir::new(value.to_string())),
             Box::new(Owner::new(
               value.to_string(),
-              matches[1].to_string().into(),
+              matches[1].to_string(),
               self.command_runner,
             )),
           ])) as Box<dyn Symbol>
@@ -110,7 +110,7 @@ impl<'a, C: CommandRunner> SymbolRepository<'a>
           )) as Box<dyn Symbol>)
         } else if let Some(matches) = self.systemd_linger.captures(value) {
           Some(Box::new(SystemdUserSession::new(
-            matches[1].to_string().into(),
+            matches[1].to_string(),
             self.command_runner,
           )) as Box<dyn Symbol>)
         } else {
diff --git a/src/for_each_tuple.rs b/src/for_each_tuple.rs
index 25c5f1e..324dc2b 100644
--- a/src/for_each_tuple.rs
+++ b/src/for_each_tuple.rs
@@ -9,7 +9,7 @@ macro_rules! for_each_tuple_ {
 }
 #[macro_export]
 macro_rules! for_each_tuple {
- ( $m:ident ) => (
- for_each_tuple_! { $m !! A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, }
- );
+  ( $m:ident ) => {
+    for_each_tuple_! { $m !! A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, }
+  };
 }
diff --git a/src/lib.rs b/src/lib.rs
index 9223116..e81dd87 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -26,6 +26,7 @@ mod for_each_tuple;
 
 pub mod bin;
 pub mod build;
+#[macro_use]
 pub mod command_runner;
 pub mod factory;
 pub mod loggers;
diff --git a/src/symbols/acme/account_key.rs b/src/symbols/acme/account_key.rs
index 2b0226d..3ab2099 100644
--- a/src/symbols/acme/account_key.rs
+++ b/src/symbols/acme/account_key.rs
@@ -1,4 +1,3 @@
-use std::borrow::Cow;
 use std::error::Error;
 use std::fmt;
 use std::path::Path;
@@ -7,13 +6,13 @@ use command_runner::CommandRunner;
 use resources::Resource;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct AcmeAccountKey<'a, C: 'a + CommandRunner> {
-  path: Cow<'a, Path>,
+pub struct AcmeAccountKey<'a, P: AsRef<Path>, C: CommandRunner> {
+  path: P,
   command_runner: &'a C,
 }
 
-impl<'a, C: CommandRunner> AcmeAccountKey<'a, C> {
-  pub fn new(path: Cow<'a, Path>, command_runner: &'a C) -> Self {
+impl<'a, P: AsRef<Path>, C: CommandRunner> AcmeAccountKey<'a, P, C> {
+  pub fn new(path: P, command_runner: &'a C) -> Self {
     AcmeAccountKey {
       path,
       command_runner,
@@ -25,26 +24,26 @@ impl<'a, C: CommandRunner> AcmeAccountKey<'a, C> {
   }
 }
 
-impl<'a, C: CommandRunner> fmt::Display for AcmeAccountKey<'a, C> {
+impl<'a, P: AsRef<Path>, C: CommandRunner> fmt::Display for AcmeAccountKey<'a, P, C> {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "AcmeAccountKey {}", self.path.display())
+    write!(f, "AcmeAccountKey {}", self.path.as_ref().display())
   }
 }
 
-impl<'a, C: CommandRunner> Symbol for AcmeAccountKey<'a, C> {
+impl<'a, P: AsRef<Path>, C: CommandRunner> Symbol for AcmeAccountKey<'a, P, C> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    if !self.path.exists() {
+    if !self.path.as_ref().exists() {
       return Ok(false);
     }
     let stdout = self.command_runner.get_output(
       "openssl",
-      &[
-        "rsa".as_ref(),
-        "-in".as_ref(),
-        self.path.as_os_str(),
-        "-noout".as_ref(),
-        "-check".as_ref(),
-        "-text".as_ref(),
+      args![
+        "rsa",
+        "-in",
+        self.path.as_ref(),
+        "-noout",
+        "-check",
+        "-text",
       ],
     )?;
     Ok(stdout.starts_with(&format!("Private-Key: ({} bit)\n", self.get_bytes()).as_bytes()))
@@ -53,20 +52,21 @@ impl<'a, C: CommandRunner> Symbol for AcmeAccountKey<'a, C> {
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     self.command_runner.run_successfully(
       "openssl",
-      &[
-        "genrsa".as_ref(),
-        "-out".as_ref(),
-        self.path.as_os_str(),
-        self.get_bytes().to_string().as_ref(),
+      args![
+        "genrsa",
+        "-out",
+        self.path.as_ref(),
+        self.get_bytes().to_string(),
       ],
     )
   }
 
   fn get_prerequisites(&self) -> Vec<Resource> {
-    vec![Resource::new(
-      "dir",
-      self.path.parent().unwrap().to_string_lossy(),
-    )]
+    if let Some(parent) = self.path.as_ref().parent() {
+      vec![Resource::new("dir", parent.to_str().unwrap())]
+    } else {
+      vec![]
+    }
   }
 
   fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
diff --git a/src/symbols/acme/cert.rs b/src/symbols/acme/cert.rs
index 2796b9b..e3f46cb 100644
--- a/src/symbols/acme/cert.rs
+++ b/src/symbols/acme/cert.rs
@@ -1,67 +1,66 @@
-use std::borrow::Cow;
 use std::error::Error;
 use std::fmt;
 use std::fs::File as FsFile;
 use std::io::Write;
-use std::path::Path;
+use std::path::PathBuf;
 
 use command_runner::CommandRunner;
 use resources::Resource;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct AcmeCert<'a, C: 'a + CommandRunner> {
-  domain: Cow<'a, str>,
+pub struct AcmeCert<'a, D: AsRef<str>, C: CommandRunner> {
+  domain: D,
   command_runner: &'a C,
 }
 
-impl<'a, C: CommandRunner> AcmeCert<'a, C> {
-  pub fn new(domain: Cow<'a, str>, command_runner: &'a C) -> Self {
+impl<'a, D: AsRef<str>, C: CommandRunner> AcmeCert<'a, D, C> {
+  pub fn new(domain: D, command_runner: &'a C) -> Self {
     AcmeCert {
       domain,
       command_runner,
     }
   }
 
-  fn get_csr_path(&self) -> String {
-    format!("/etc/ssl/local_certs/{}.csr", self.domain)
+  fn get_csr_path(&self) -> PathBuf {
+    format!("/etc/ssl/local_certs/{}.csr", self.domain.as_ref()).into()
   }
 
-  fn get_cert_path(&self) -> String {
-    format!("/etc/ssl/local_certs/{}.crt", self.domain)
+  fn get_cert_path(&self) -> PathBuf {
+    format!("/etc/ssl/local_certs/{}.crt", self.domain.as_ref()).into()
   }
 }
 
-impl<'a, C: CommandRunner> fmt::Display for AcmeCert<'a, C> {
+impl<'a, D: AsRef<str>, C: CommandRunner> fmt::Display for AcmeCert<'a, D, C> {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "AcmeCert {}", self.domain)
+    write!(f, "AcmeCert {}", self.domain.as_ref())
   }
 }
 
 const DAYS_IN_SECONDS: u32 = 24 * 60 * 60;
 
-impl<'a, C: CommandRunner> Symbol for AcmeCert<'a, C> {
+impl<'a, D: AsRef<str>, C: CommandRunner> Symbol for AcmeCert<'a, D, C> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    if !Path::new(&self.get_cert_path()).exists() {
+    if !self.get_cert_path().exists() {
       return Ok(false);
     }
 
     let output = self.command_runner.run_with_args(
       "openssl",
-      &[
+      args![
         "x509",
         "-in",
-        &self.get_cert_path(),
+        self.get_cert_path(),
         "-noout",
         "-subject",
         "-checkend",
-        &(30 * DAYS_IN_SECONDS).to_string(),
+        (30 * DAYS_IN_SECONDS).to_string(),
       ],
     )?;
     if output.status.success()
       && output.stdout
         == format!(
           "subject=CN = {}\nCertificate will not expire\n",
-          self.domain
+          self.domain.as_ref()
         )
         .as_bytes()
     {
@@ -70,18 +69,22 @@ impl<'a, C: CommandRunner> Symbol for AcmeCert<'a, C> {
           .command_runner
           .run_successfully(
             "openssl",
-            &[
+            args![
               "verify",
               "--untrusted",
               "/home/acme/lets_encrypt_x3_cross_signed.pem",
-              &self.get_cert_path(),
+              self.get_cert_path(),
             ],
           )
           .is_ok(),
       )
     } else if output.status.code() == Some(1)
       && output.stdout
-        == format!("subject=CN = {}\nCertificate will expire\n", self.domain).as_bytes()
+        == format!(
+          "subject=CN = {}\nCertificate will expire\n",
+          self.domain.as_ref()
+        )
+        .as_bytes()
     {
       Ok(false)
     } else {
@@ -92,11 +95,11 @@ impl<'a, C: CommandRunner> Symbol for AcmeCert<'a, C> {
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     let output = self.command_runner.get_output(
       "acme-tiny",
-      &[
+      args![
         "--account-key",
         "/home/acme/account.key",
         "--csr",
-        &self.get_csr_path(),
+        self.get_csr_path(),
         "--acme-dir",
         "/home/acme/challenges/",
       ],
@@ -107,7 +110,7 @@ impl<'a, C: CommandRunner> Symbol for AcmeCert<'a, C> {
   }
 
   fn get_prerequisites(&self) -> Vec<Resource> {
-    vec![Resource::new("file", self.get_csr_path())]
+    vec![Resource::new("file", self.get_csr_path().to_str().unwrap())]
   }
 
   fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
diff --git a/src/symbols/acme/chain.rs b/src/symbols/acme/chain.rs
index c8c0ddc..5ee8921 100644
--- a/src/symbols/acme/chain.rs
+++ b/src/symbols/acme/chain.rs
@@ -1,66 +1,65 @@
-use std::borrow::Cow;
 use std::error::Error;
 use std::fmt;
 use std::fs::File as FsFile;
 use std::io::Write;
-use std::path::Path;
+use std::path::PathBuf;
 
 use command_runner::CommandRunner;
 use resources::Resource;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct AcmeCertChain<'a, C: 'a + CommandRunner> {
-  domain: Cow<'a, str>,
+pub struct AcmeCertChain<'a, D: AsRef<str>, C: CommandRunner> {
+  domain: D,
   command_runner: &'a C,
 }
 
-impl<'a, C: CommandRunner> AcmeCertChain<'a, C> {
-  pub fn new(domain: Cow<'a, str>, command_runner: &'a C) -> Self {
+impl<'a, D: AsRef<str>, C: CommandRunner> AcmeCertChain<'a, D, C> {
+  pub fn new(domain: D, command_runner: &'a C) -> Self {
     AcmeCertChain {
       domain,
       command_runner,
     }
   }
 
-  fn get_single_cert_path(&self) -> String {
-    format!("/etc/ssl/local_certs/{}.crt", self.domain)
+  fn get_single_cert_path(&self) -> PathBuf {
+    format!("/etc/ssl/local_certs/{}.crt", self.domain.as_ref()).into()
   }
 
-  fn get_cert_chain_path(&self) -> String {
-    format!("/etc/ssl/local_certs/{}.chained.crt", self.domain)
+  fn get_cert_chain_path(&self) -> PathBuf {
+    format!("/etc/ssl/local_certs/{}.chained.crt", self.domain.as_ref()).into()
   }
 }
 
-impl<'a, C: CommandRunner> fmt::Display for AcmeCertChain<'a, C> {
+impl<'a, D: AsRef<str>, C: CommandRunner> fmt::Display for AcmeCertChain<'a, D, C> {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "AcmeCertChain {}", self.domain)
+    write!(f, "AcmeCertChain {}", self.domain.as_ref())
   }
 }
 
 const DAYS_IN_SECONDS: u32 = 24 * 60 * 60;
 
-impl<'a, C: CommandRunner> Symbol for AcmeCertChain<'a, C> {
+impl<'a, D: AsRef<str>, C: CommandRunner> Symbol for AcmeCertChain<'a, D, C> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    if !Path::new(&self.get_cert_chain_path()).exists() {
+    if !self.get_cert_chain_path().exists() {
       return Ok(false);
     }
 
     let stdout = self.command_runner.get_output(
       "openssl",
-      &[
+      args![
         "x509",
         "-in",
-        &self.get_cert_chain_path(),
+        self.get_cert_chain_path(),
         "-noout",
         "-subject",
         "-checkend",
-        &(30 * DAYS_IN_SECONDS).to_string(),
+        (30 * DAYS_IN_SECONDS).to_string(),
       ],
     )?;
     if stdout
       != format!(
         "subject=CN = {}\nCertificate will not expire\n",
-        self.domain
+        self.domain.as_ref()
       )
       .as_bytes()
     {
@@ -72,11 +71,11 @@ impl<'a, C: CommandRunner> Symbol for AcmeCertChain<'a, C> {
         .command_runner
         .run_successfully(
           "openssl",
-          &[
+          args![
             "verify",
             "-untrusted",
             "/home/acme/lets_encrypt_x3_cross_signed.pem",
-            &self.get_cert_chain_path(),
+            self.get_cert_chain_path(),
           ],
         )
         .is_ok(),
@@ -86,8 +85,8 @@ impl<'a, C: CommandRunner> Symbol for AcmeCertChain<'a, C> {
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     let output = self.command_runner.get_output(
       "cat",
-      &[
-        self.get_single_cert_path().as_ref(),
+      args![
+        self.get_single_cert_path(),
         "/home/acme/lets_encrypt_x3_cross_signed.pem",
       ],
     )?;
@@ -97,7 +96,10 @@ impl<'a, C: CommandRunner> Symbol for AcmeCertChain<'a, C> {
   }
 
   fn get_prerequisites(&self) -> Vec<Resource> {
-    vec![Resource::new("file", self.get_single_cert_path())]
+    vec![Resource::new(
+      "file",
+      self.get_single_cert_path().to_str().unwrap(),
+    )]
   }
 
   fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
diff --git a/src/symbols/acme/user.rs b/src/symbols/acme/user.rs
index 927469d..0ba21d5 100644
--- a/src/symbols/acme/user.rs
+++ b/src/symbols/acme/user.rs
@@ -1,9 +1,4 @@
-use resources::Resource;
-use std::borrow::{Borrow, Cow};
-use std::error::Error;
-use std::fmt;
-use std::ops::Deref;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use command_runner::CommandRunner;
 use symbols::acme::AcmeAccountKey;
@@ -11,72 +6,32 @@ use symbols::dir::Dir;
 use symbols::file::File;
 use symbols::list::List;
 use symbols::owner::Owner;
-use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
+use symbols::Symbol;
 
-pub struct AcmeUser<'a>(Cow<'a, str>);
-
-impl<'a> AcmeUser<'a> {
-  pub fn new<S: Into<Cow<'a, str>>>(user_name: S) -> Self {
-    AcmeUser(user_name.into())
-  }
-}
-
-impl<'a> Symbol for AcmeUser<'a> {
-  fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    Ok(false)
-  }
-  fn execute(&self) -> Result<(), Box<dyn Error>> {
-    Ok(())
-  }
-  fn get_prerequisites(&self) -> Vec<Resource> {
-    vec![]
-  }
-  fn provides(&self) -> Option<Vec<Resource>> {
-    None
-  }
-  fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
-    Box::new(SymbolAction::new(runner, self))
-  }
-
-  fn into_action<'b>(self: Box<Self>, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b>
-  where
-    Self: 'b,
-  {
-    Box::new(OwnedSymbolAction::new(runner, *self))
-  }
-}
-
-impl<'a> fmt::Display for AcmeUser<'a> {
-  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "AcmeUser {}", self.0)
-  }
-}
-
-pub fn new<'a, S: Into<Cow<'a, str>>, C: CommandRunner, P: 'a + Deref<Target = str>>(
-  command_runner: &'a C,
-  cert: P,
-  user_name: S,
+pub fn new<'a, R: CommandRunner, C: 'a + AsRef<str>, U: 'a + AsRef<str>, H: AsRef<Path>>(
+  command_runner: &'a R,
+  cert: C,
+  user_name: U,
+  home: H,
 ) -> impl Symbol + 'a {
-  // impl trait
-  let user_name_cow = user_name.into();
-  let account_key_file: PathBuf = ["/home", user_name_cow.borrow(), "account.key"]
-    .iter()
-    .collect();
+  let path = |rel: &str| [home.as_ref(), rel.as_ref()].iter().collect::<PathBuf>();
+  let account_key_file = path("account.key");
   List::from((
-    AcmeAccountKey::new(account_key_file.clone().into(), command_runner),
+    AcmeAccountKey::new(account_key_file.clone(), command_runner),
+    // FIXME into or cow or clone
     Owner::new(
-      account_key_file.to_string_lossy().into_owned(),
-      user_name_cow.clone(),
+      account_key_file,
+      user_name.as_ref().to_owned(),
       command_runner,
     ),
-    Dir::new("/home/acme/challenges"),
+    Dir::new(path("challenges")),
     Owner::new(
-      "/home/acme/challenges",
-      user_name_cow.clone(),
+      path("challenges"),
+      user_name.as_ref().to_owned(),
       command_runner,
     ),
     Dir::new("/etc/ssl/local_certs"),
-    Owner::new("/etc/ssl/local_certs", user_name_cow, command_runner),
-    File::new("/home/acme/lets_encrypt_x3_cross_signed.pem", cert),
+    Owner::new("/etc/ssl/local_certs", user_name, command_runner),
+    File::new(path("lets_encrypt_x3_cross_signed.pem"), cert),
   ))
 }
diff --git a/src/symbols/cron.rs b/src/symbols/cron.rs
index 23ca311..1e68da6 100644
--- a/src/symbols/cron.rs
+++ b/src/symbols/cron.rs
@@ -1,51 +1,39 @@
 use std::error::Error;
 use std::fmt;
-use std::ops::Deref;
 
 use command_runner::CommandRunner;
-use resources::Resource;
+
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct Cron<'r, C, U, R: 'r + CommandRunner>
-where
-  C: Deref<Target = str>,
-  U: Deref<Target = str>,
-{
+pub struct Cron<'r, C: AsRef<str>, U: AsRef<str>, R: CommandRunner> {
   user: U,
   content: C,
   command_runner: &'r R,
 }
 
-impl<'r, U, R: 'r + CommandRunner> Cron<'r, String, U, R>
-where
-  U: Deref<Target = str>,
-{
-  pub fn new<C: Deref<Target = str>>(user: U, content: C, command_runner: &'r R) -> Self {
+impl<'r, U: AsRef<str>, R: CommandRunner> Cron<'r, String, U, R> {
+  pub fn new<C: AsRef<str>>(user: U, content: C, command_runner: &'r R) -> Self {
     Cron {
       user,
-      content: String::from(&*content) + "\n",
+      content: String::from(content.as_ref()) + "\n",
       command_runner,
     }
   }
 }
 
-impl<'r, C, U, R: 'r + CommandRunner> Symbol for Cron<'r, C, U, R>
-where
-  C: Deref<Target = str>,
-  U: Deref<Target = str>,
-{
+impl<'r, C: AsRef<str>, U: AsRef<str>, R: CommandRunner> Symbol for Cron<'r, C, U, R> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     let tab = self
       .command_runner
-      .get_output("crontab", &["-l", "-u", &self.user])?;
-    Ok(tab == self.content.bytes().collect::<Vec<u8>>())
+      .get_output("crontab", args!["-l", "-u", self.user.as_ref(),])?;
+    Ok(tab == self.content.as_ref().bytes().collect::<Vec<u8>>())
   }
 
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     let output = self.command_runner.run_with_args_and_stdin(
       "crontab",
-      &["-u", &self.user, "-"],
-      &self.content,
+      args!["-u", self.user.as_ref(), "-",],
+      self.content.as_ref(),
     )?;
     if !output.status.success() {
       return Err(String::from_utf8(output.stderr)?.into());
@@ -53,10 +41,6 @@ where
     Ok(())
   }
 
-  fn get_prerequisites(&self) -> Vec<Resource> {
-    vec![]
-  }
-
   fn as_action<'a>(&'a self, runner: &'a dyn SymbolRunner) -> Box<dyn Action + 'a> {
     Box::new(SymbolAction::new(runner, self))
   }
@@ -69,12 +53,8 @@ where
   }
 }
 
-impl<'r, C, U, R: 'r + CommandRunner> fmt::Display for Cron<'r, C, U, R>
-where
-  C: Deref<Target = str>,
-  U: Deref<Target = str>,
-{
+impl<'r, C: AsRef<str>, U: AsRef<str>, R: CommandRunner> fmt::Display for Cron<'r, C, U, R> {
   fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-    write!(f, "Cron {}", &*self.user)
+    write!(f, "Cron {}", self.user.as_ref())
   }
 }
diff --git a/src/symbols/dir.rs b/src/symbols/dir.rs
index 7b38b77..d2414f3 100644
--- a/src/symbols/dir.rs
+++ b/src/symbols/dir.rs
@@ -7,44 +7,29 @@ use std::path::Path;
 use resources::Resource;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct Dir<D>
-where
-  D: AsRef<str>,
-{
+pub struct Dir<D: AsRef<Path>> {
   path: D,
 }
 
-impl<D> Dir<D>
-where
-  D: AsRef<str>,
-{
+impl<D: AsRef<Path>> Dir<D> {
   pub fn new(path: D) -> Self {
     Dir { path }
   }
 }
 
-impl<D> Symbol for Dir<D>
-where
-  D: AsRef<str>,
-{
+impl<D: AsRef<Path>> Symbol for Dir<D> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    let metadata = fs::metadata(self.path.as_ref());
-    // Check if dir exists
-    if let Err(e) = metadata {
-      return if e.kind() == io::ErrorKind::NotFound {
-        Ok(false)
-      } else {
-        Err(Box::new(e))
-      };
+    if !self.path.as_ref().exists() {
+      return Ok(false);
     }
-    if metadata.unwrap().is_dir() {
-      Ok(true)
-    } else {
-      Err(Box::new(io::Error::new(
+    let metadata = fs::metadata(self.path.as_ref())?;
+    if !metadata.is_dir() {
+      return Err(Box::new(io::Error::new(
         io::ErrorKind::AlreadyExists,
         "Could not create a directory, non-directory file exists",
-      )))
+      )));
     }
+    Ok(true)
   }
 
   fn execute(&self) -> Result<(), Box<dyn Error>> {
@@ -52,15 +37,18 @@ where
   }
 
   fn get_prerequisites(&self) -> Vec<Resource> {
-    if let Some(parent) = Path::new(self.path.as_ref()).parent() {
-      vec![Resource::new("dir", parent.to_string_lossy())]
+    if let Some(parent) = self.path.as_ref().parent() {
+      vec![Resource::new("dir", parent.to_str().unwrap())]
     } else {
       vec![]
     }
   }
 
   fn provides(&self) -> Option<Vec<Resource>> {
-    Some(vec![Resource::new("dir", self.path.as_ref())])
+    Some(vec![Resource::new(
+      "dir",
+      self.path.as_ref().to_str().unwrap(),
+    )])
   }
 
   fn as_action<'a>(&'a self, runner: &'a dyn SymbolRunner) -> Box<dyn Action + 'a> {
@@ -75,11 +63,8 @@ where
   }
 }
 
-impl<D> fmt::Display for Dir<D>
-where
-  D: AsRef<str>,
-{
+impl<D: AsRef<Path>> fmt::Display for Dir<D> {
   fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-    write!(f, "Dir {}", self.path.as_ref())
+    write!(f, "Dir {}", self.path.as_ref().display())
   }
 }
diff --git a/src/symbols/factory.rs b/src/symbols/factory.rs
index e18014c..c8e8654 100644
--- a/src/symbols/factory.rs
+++ b/src/symbols/factory.rs
@@ -1,20 +1,22 @@
 use std::borrow::Cow;
-use std::ops::Deref;
+
 use std::path::Path;
+use std::path::PathBuf;
 
 use command_runner::{CommandRunner, SetuidCommandRunner};
 use storage::{SimpleStorage, Storage};
-use symbols::acme::{AcmeCert, AcmeCertChain};
+use symbols::acme::{newAcmeUser, AcmeCert, AcmeCertChain};
 use symbols::cron::Cron;
 use symbols::file::File;
 use symbols::git::checkout::GitCheckout;
 use symbols::hook::Hook;
 use symbols::list::List;
 use symbols::mariadb::{DatabaseDump, MariaDBDatabase, MariaDBUser};
-use symbols::nginx::server::{php_server_config_snippet, server_config, NginxServer};
+use symbols::nginx::server::{server_config, NginxServer};
 use symbols::owner::Owner;
 use symbols::stored_directory::{StorageDirection, StoredDirectory};
 use symbols::systemd::reload::ReloadService;
+use symbols::systemd::user_service::UserService;
 use symbols::tls::SelfSignedTlsCert;
 use symbols::{Symbol, SymbolRunner};
 
@@ -22,8 +24,11 @@ pub trait Policy {
   fn user_name_for_host(&self, host_name: &'static str) -> String {
     host_name.split('.').rev().fold(String::new(), |result, part| if result.is_empty() { result } else { result + "_" } + part)
   }
-  fn home_for_user(&self, user_name: &str) -> String {
-    format!("/home/{}", user_name)
+  fn home_for_user(&self, user_name: &str) -> PathBuf {
+    format!("/home/{}", user_name).into()
+  }
+  fn socket_path(&self, user_name: &str, service_name: &str) -> PathBuf {
+    format!("/var/tmp/{}-{}.socket", user_name, service_name).into()
   }
 }
 
@@ -42,7 +47,7 @@ impl<'b, C: 'b + CommandRunner, R: 'b + SymbolRunner, P: 'b + Policy> SymbolFact
   pub fn new(command_runner: &'b C, symbol_runner: &'b R, policy: &'b P) -> Self {
     let acme_user = "acme"; // FIXME: CONFIG
 
-    let acme_command_runner = SetuidCommandRunner::new(acme_user, command_runner);
+    let acme_command_runner = SetuidCommandRunner::new(acme_user.into(), command_runner);
     SymbolFactory {
       command_runner,
       acme_command_runner,
@@ -57,14 +62,14 @@ impl<'b, C: 'b + CommandRunner, R: 'b + SymbolRunner, P: 'b + Policy> SymbolFact
     nginx_server_symbol: S,
   ) -> impl Symbol + 'a {
     List::from((
-      SelfSignedTlsCert::new(host.into(), self.command_runner),
+      SelfSignedTlsCert::new(host, self.command_runner),
       Hook::new(
         nginx_server_symbol,
         ReloadService::new("nginx", self.command_runner),
       ),
-      AcmeCert::new(host.into(), &self.acme_command_runner),
+      AcmeCert::new(host, &self.acme_command_runner),
       Hook::new(
-        AcmeCertChain::new(host.into(), &self.acme_command_runner),
+        AcmeCertChain::new(host, &self.acme_command_runner),
         ReloadService::new("nginx", self.command_runner),
       ),
     ))
@@ -79,8 +84,8 @@ impl<'b, C: 'b + CommandRunner, R: 'b + SymbolRunner, P: 'b + Policy> SymbolFact
     )
   }
 
-  fn get_php_fpm_pool_socket_path<'a>(&'a self, user_name: &str) -> String {
-    format!("/run/php/{}.sock", user_name)
+  fn get_php_fpm_pool_socket_path<'a>(&'a self, user_name: &str) -> PathBuf {
+    format!("/run/php/{}.sock", user_name).into()
   }
 
   fn get_php_fpm_pool<'a>(&'a self, user_name: &str) -> impl Symbol + 'a {
@@ -100,17 +105,18 @@ pm.max_children = 10
 catch_workers_output = yes
 env[PATH] = /usr/local/bin:/usr/bin:/bin
 ",
-          user_name, socket
+          user_name,
+          socket.to_str().unwrap()
         ),
       ),
       ReloadService::new("php7.0-fpm", self.command_runner),
     )
   }
 
-  pub fn serve_php<'a>(
+  pub fn serve_php<'a, ROOT: AsRef<Path>>(
     &'a self,
     host_name: &'static str,
-    root_dir: Cow<'a, str>,
+    root_dir: ROOT,
     additional_config: &'a str,
   ) -> impl Symbol + 'a {
     let user_name = self.policy.user_name_for_host(host_name);
@@ -121,7 +127,7 @@ env[PATH] = /usr/local/bin:/usr/bin:/bin
         host_name,
         NginxServer::new_php(
           host_name,
-          socket.into(),
+          socket,
           root_dir,
           self.command_runner,
           additional_config,
@@ -130,10 +136,10 @@ env[PATH] = /usr/local/bin:/usr/bin:/bin
     ))
   }
 
-  pub fn serve_wordpress<'a>(
+  pub fn serve_wordpress<'a, ROOT: 'a + AsRef<Path>>(
     &'a self,
     host_name: &'static str,
-    root_dir: Cow<'a, str>,
+    root_dir: ROOT,
   ) -> impl Symbol + 'a {
     self.serve_php(
       host_name,
@@ -179,16 +185,16 @@ env[PATH] = /usr/local/bin:/usr/bin:/bin
       }}
   ",
         root_dir,
-        socket)),
+        socket.to_str().unwrap())),
         self.command_runner
       ))
     ))
   }
 
-  pub fn serve_nextcloud<'a>(
+  pub fn serve_nextcloud<'a, ROOT: 'a + AsRef<Path>>(
     &'a self,
     host_name: &'static str,
-    root_dir: Cow<'a, str>,
+    root_dir: ROOT,
   ) -> impl Symbol + 'a {
     self.serve_php(
       host_name,
@@ -272,13 +278,13 @@ env[PATH] = /usr/local/bin:/usr/bin:/bin
     let string_target = target.into();
     (
       StoredDirectory::new(
-        string_target.clone().into(),
+        string_target.clone(),
         data.clone(),
         StorageDirection::Save,
         self.command_runner,
       ),
       StoredDirectory::new(
-        string_target.into(),
+        string_target,
         data.clone(),
         StorageDirection::Load,
         self.command_runner,
@@ -290,11 +296,8 @@ env[PATH] = /usr/local/bin:/usr/bin:/bin
     let db_dump = SimpleStorage::new("/root/data".to_string(), format!("{}.sql", name));
     List::from((
       MariaDBDatabase::new(
-        name.into(),
-        db_dump
-          .read_filename()
-          .expect("Initial db dump missing")
-          .into(),
+        name,
+        db_dump.read_filename().expect("Initial db dump missing"),
         self.command_runner,
       ),
       DatabaseDump::new(name, db_dump, self.command_runner),
@@ -302,10 +305,10 @@ env[PATH] = /usr/local/bin:/usr/bin:/bin
   }
 
   pub fn get_mariadb_user<'a>(&'a self, user_name: &'static str) -> impl Symbol + 'a {
-    MariaDBUser::new(user_name.into(), self.command_runner)
+    MariaDBUser::new(user_name, self.command_runner)
   }
 
-  pub fn get_git_checkout<'a, T: 'a + AsRef<str>>(
+  pub fn get_git_checkout<'a, T: 'a + AsRef<Path>>(
     &'a self,
     target: T,
     source: &'a str,
@@ -314,11 +317,15 @@ env[PATH] = /usr/local/bin:/usr/bin:/bin
     GitCheckout::new(target, source, branch, self.command_runner)
   }
 
-  pub fn get_owner<'a, F: 'a + AsRef<str>>(&'a self, file: F, user: &'a str) -> impl Symbol + 'a {
-    Owner::new(file, user.into(), self.command_runner)
+  pub fn get_owner<'a, U: 'a + AsRef<str>, F: 'a + AsRef<Path>>(
+    &'a self,
+    file: F,
+    user: U,
+  ) -> impl Symbol + 'a {
+    Owner::new(file, user, self.command_runner)
   }
 
-  pub fn get_file<'a, F: 'a + Deref<Target = str>, Q: 'a + AsRef<Path>>(
+  pub fn get_file<'a, F: 'a + AsRef<str>, Q: 'a + AsRef<Path>>(
     &'a self,
     path: Q,
     content: F,
@@ -326,11 +333,94 @@ env[PATH] = /usr/local/bin:/usr/bin:/bin
     File::new(path, content)
   }
 
-  pub fn get_cron<'a, T: 'a + Deref<Target = str>, U: 'a + Deref<Target = str>>(
+  pub fn get_cron<'a, T: 'a + AsRef<str>, U: 'a + AsRef<str>>(
     &'a self,
     user: U,
     content: T,
   ) -> impl Symbol + 'a {
     Cron::new(user, content, self.command_runner)
   }
+
+  pub fn get_acme_user<'a, S: 'a + AsRef<str>, D: 'a + AsRef<str>>(
+    &'a self,
+    cert: D,
+    user_name: S,
+  ) -> impl Symbol + 'a {
+    let home = self.policy.home_for_user(user_name.as_ref());
+    newAcmeUser(self.command_runner, cert, user_name, home)
+  }
+
+  pub fn get_systemd_user_service<'a>(
+    &'a self,
+    user_name: Cow<'a, str>,
+    service_name: &'a str,
+    config: Cow<'a, str>,
+  ) -> impl Symbol + 'a {
+    let socket_path = self.policy.socket_path(&user_name, service_name);
+    let home = self.policy.home_for_user(&user_name);
+    UserService::new(
+      socket_path.into(),
+      home.into(),
+      user_name,
+      service_name,
+      self.command_runner,
+      config.into(),
+    )
+  }
+
+  fn get_nodejs_systemd_user_service<'a, T: Into<Cow<'a, Path>>>(
+    &'a self,
+    user_name: Cow<'a, str>,
+    service_name: &'a str,
+    path: T,
+  ) -> impl Symbol + 'a {
+    let socket_path = self.policy.socket_path(&user_name, service_name);
+    let home = self.policy.home_for_user(&user_name);
+    UserService::new_nodejs(
+      home.into(),
+      user_name,
+      service_name,
+      path.into(),
+      self.command_runner,
+      socket_path.into(),
+    )
+  }
+
+  pub fn proxy_socket<'a, T: Into<Cow<'a, Path>>>(
+    &'a self,
+    host_name: &'static str,
+    service_name: &'a str,
+    root_dir: T,
+  ) -> impl Symbol + 'a {
+    let user_name = self.policy.user_name_for_host(host_name);
+    let socket_path = self.policy.socket_path(&user_name, service_name);
+    self.get_nginx_acme_server(
+      host_name,
+      NginxServer::new_proxy(host_name, socket_path, root_dir.into(), self.command_runner),
+    )
+  }
+
+  pub fn serve_nodejs<
+    'a,
+    'c: 'a,
+    S: 'a + Symbol,
+    T: 'a + Into<Cow<'a, Path>>,
+    SP: 'a + Into<Cow<'a, Path>>,
+  >(
+    &'c self,
+    host: &'static str,
+    service_name: &'a str,
+    path: T,
+    static_path: SP,
+    nodejs_symbol: S,
+  ) -> impl Symbol + 'a {
+    let user_name = self.policy.user_name_for_host(host);
+    List::from((
+      Hook::new(
+        nodejs_symbol,
+        self.get_nodejs_systemd_user_service(user_name.into(), service_name, path),
+      ),
+      self.proxy_socket(host, service_name, static_path),
+    ))
+  }
 }
diff --git a/src/symbols/file.rs b/src/symbols/file.rs
index dcc1ce3..1c20183 100644
--- a/src/symbols/file.rs
+++ b/src/symbols/file.rs
@@ -1,51 +1,34 @@
 use std::error::Error;
 use std::fmt;
 use std::fs::File as FsFile;
-use std::io;
+
 use std::io::{Read, Write};
-use std::ops::Deref;
+
 use std::path::Path;
 
 use resources::Resource;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct File<C, D>
-where
-  C: Deref<Target = str>,
-  D: AsRef<Path>,
-{
+pub struct File<C: AsRef<str>, D: AsRef<Path>> {
   path: D,
   content: C,
 }
 
-impl<C, D> File<C, D>
-where
-  C: Deref<Target = str>,
-  D: AsRef<Path>,
-{
+impl<C: AsRef<str>, D: AsRef<Path>> File<C, D> {
   pub fn new(path: D, content: C) -> Self {
     File { path, content }
   }
 }
 
-impl<C, D> Symbol for File<C, D>
-where
-  C: Deref<Target = str>,
-  D: AsRef<Path>,
-{
+impl<C: AsRef<str>, D: AsRef<Path>> Symbol for File<C, D> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    let file = FsFile::open(self.path.as_ref());
-    // Check if file exists
-    if let Err(e) = file {
-      return if e.kind() == io::ErrorKind::NotFound {
-        Ok(false)
-      } else {
-        Err(Box::new(e))
-      };
+    if !self.path.as_ref().exists() {
+      return Ok(false);
     }
+    let file = FsFile::open(self.path.as_ref())?;
     // Check if content is the same
-    let mut file_content = file.unwrap().bytes();
-    let mut target_content = self.content.bytes();
+    let mut file_content = file.bytes();
+    let mut target_content = self.content.as_ref().bytes();
     loop {
       match (file_content.next(), target_content.next()) {
         (None, None) => return Ok(true),
@@ -58,18 +41,16 @@ where
 
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     let mut file = FsFile::create(self.path.as_ref())?;
-    file.write_all(self.content.as_bytes())?;
+    file.write_all(self.content.as_ref().as_bytes())?;
     Ok(())
   }
 
   fn get_prerequisites(&self) -> Vec<Resource> {
-    vec![Resource::new(
-      "dir",
-      Path::new(self.path.as_ref())
-        .parent()
-        .unwrap()
-        .to_string_lossy(),
-    )]
+    if let Some(parent) = self.path.as_ref().parent() {
+      vec![Resource::new("dir", parent.to_str().unwrap())]
+    } else {
+      vec![]
+    }
   }
 
   fn as_action<'a>(&'a self, runner: &'a dyn SymbolRunner) -> Box<dyn Action + 'a> {
@@ -84,11 +65,7 @@ where
   }
 }
 
-impl<C, D> fmt::Display for File<C, D>
-where
-  C: Deref<Target = str>,
-  D: AsRef<Path>,
-{
+impl<C: AsRef<str>, D: AsRef<Path>> fmt::Display for File<C, D> {
   fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
     write!(f, "File {}", self.path.as_ref().display())
   }
diff --git a/src/symbols/git/checkout.rs b/src/symbols/git/checkout.rs
index 42e9d7e..88b26b7 100644
--- a/src/symbols/git/checkout.rs
+++ b/src/symbols/git/checkout.rs
@@ -1,5 +1,7 @@
 use std::error::Error;
+use std::ffi::OsStr;
 use std::fmt;
+use std::fs::metadata;
 use std::io;
 use std::path::Path;
 
@@ -7,14 +9,14 @@ use command_runner::CommandRunner;
 use resources::Resource;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct GitCheckout<'a, C: 'a + CommandRunner, T: AsRef<str>> {
+pub struct GitCheckout<'a, C: CommandRunner, T: AsRef<Path>> {
   target: T,
   source: &'a str,
   branch: &'a str,
   command_runner: &'a C,
 }
 
-impl<'a, C: CommandRunner, T: AsRef<str>> GitCheckout<'a, C, T> {
+impl<'a, C: CommandRunner, T: AsRef<Path>> GitCheckout<'a, C, T> {
   pub fn new(target: T, source: &'a str, branch: &'a str, command_runner: &'a C) -> Self {
     GitCheckout {
       target,
@@ -25,29 +27,27 @@ impl<'a, C: CommandRunner, T: AsRef<str>> GitCheckout<'a, C, T> {
   }
 }
 
-impl<'a, C: CommandRunner, T: AsRef<str>> fmt::Display for GitCheckout<'a, C, T> {
+impl<'a, C: CommandRunner, T: AsRef<Path>> fmt::Display for GitCheckout<'a, C, T> {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
     write!(
       f,
       "Checkout {} (branch {}) into {}",
       self.source,
       self.branch,
-      self.target.as_ref()
+      self.target.as_ref().display()
     )
   }
 }
 
-use std::fs::metadata;
-
-impl<'a, C: CommandRunner, T: AsRef<str>> GitCheckout<'a, C, T> {
-  fn _run_in_target_repo(&self, args: &[&str]) -> Result<Vec<u8>, Box<dyn Error>> {
-    let mut new_args = vec!["-C", self.target.as_ref()];
-    new_args.extend_from_slice(args);
+impl<'a, C: CommandRunner, T: AsRef<Path>> GitCheckout<'a, C, T> {
+  fn _run_in_target_repo<S: AsRef<OsStr>>(&self, args: &[S]) -> Result<Vec<u8>, Box<dyn Error>> {
+    let mut new_args = vec![OsStr::new("-C"), self.target.as_ref().as_ref()];
+    new_args.extend(args.iter().map(AsRef::as_ref));
     self.command_runner.get_output("git", &new_args)
   }
 }
 
-impl<'a, C: CommandRunner, T: AsRef<str>> Symbol for GitCheckout<'a, C, T> {
+impl<'a, C: CommandRunner, T: AsRef<Path>> Symbol for GitCheckout<'a, C, T> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     if let Err(e) = metadata(self.target.as_ref()) {
       return if e.kind() == io::ErrorKind::NotFound {
@@ -64,17 +64,17 @@ impl<'a, C: CommandRunner, T: AsRef<str>> Symbol for GitCheckout<'a, C, T> {
   }
 
   fn execute(&self) -> Result<(), Box<dyn Error>> {
-    if !Path::new(self.target.as_ref()).exists() {
+    if !self.target.as_ref().exists() {
       return self.command_runner.run_successfully(
         "git",
         &[
-          "clone",
-          "--depth",
-          "1",
-          "-b",
-          self.branch,
-          self.source,
-          self.target.as_ref(),
+          OsStr::new("clone"),
+          "--depth".as_ref(),
+          "1".as_ref(),
+          "-b".as_ref(),
+          self.branch.as_ref(),
+          self.source.as_ref(),
+          self.target.as_ref().as_ref(),
         ],
       );
     }
@@ -86,15 +86,15 @@ impl<'a, C: CommandRunner, T: AsRef<str>> Symbol for GitCheckout<'a, C, T> {
   fn get_prerequisites(&self) -> Vec<Resource> {
     vec![Resource::new(
       "dir",
-      Path::new(self.target.as_ref())
-        .parent()
-        .unwrap()
-        .to_string_lossy(),
+      self.target.as_ref().parent().unwrap().to_string_lossy(),
     )]
   }
 
   fn provides(&self) -> Option<Vec<Resource>> {
-    Some(vec![Resource::new("dir", self.target.as_ref().to_string())])
+    Some(vec![Resource::new(
+      "dir",
+      self.target.as_ref().to_str().unwrap(),
+    )])
   }
 
   fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
diff --git a/src/symbols/git/submodules.rs b/src/symbols/git/submodules.rs
index 1adc7fc..81dcad8 100644
--- a/src/symbols/git/submodules.rs
+++ b/src/symbols/git/submodules.rs
@@ -1,17 +1,18 @@
 use std::error::Error;
+use std::ffi::OsStr;
 use std::fmt;
 use std::path::Path;
 
 use command_runner::CommandRunner;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct GitSubmodules<'a, C: 'a + CommandRunner> {
-  target: &'a str,
+pub struct GitSubmodules<'a, P: AsRef<Path>, C: CommandRunner> {
+  target: P,
   command_runner: &'a C,
 }
 
-impl<'a, C: CommandRunner> GitSubmodules<'a, C> {
-  pub fn new(target: &'a str, command_runner: &'a C) -> Self {
+impl<'a, P: AsRef<Path>, C: CommandRunner> GitSubmodules<'a, P, C> {
+  pub fn new(target: P, command_runner: &'a C) -> Self {
     GitSubmodules {
       target,
       command_runner,
@@ -19,26 +20,27 @@ impl<'a, C: CommandRunner> GitSubmodules<'a, C> {
   }
 }
 
-impl<'a, C: CommandRunner> fmt::Display for GitSubmodules<'a, C> {
+impl<'a, P: AsRef<Path>, C: CommandRunner> fmt::Display for GitSubmodules<'a, P, C> {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "Submodules for {}", self.target)
+    write!(f, "Submodules for {}", self.target.as_ref().display())
   }
 }
 
-impl<'a, C: CommandRunner> GitSubmodules<'a, C> {
-  fn _run_in_target_repo(&self, args: &[&str]) -> Result<Vec<u8>, Box<dyn Error>> {
-    let mut new_args = vec!["-C", self.target];
+impl<'a, P: AsRef<Path>, C: CommandRunner> GitSubmodules<'a, P, C> {
+  fn _run_in_target_repo(&self, args: &[&OsStr]) -> Result<Vec<u8>, Box<dyn Error>> {
+    let mut new_args: Vec<&OsStr> = vec![];
+    new_args.extend_from_slice(args!["-C", self.target.as_ref()]);
     new_args.extend_from_slice(args);
     self.command_runner.get_output("git", &new_args)
   }
 }
 
-impl<'a, C: CommandRunner> Symbol for GitSubmodules<'a, C> {
+impl<'a, P: AsRef<Path>, C: CommandRunner> Symbol for GitSubmodules<'a, P, C> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    if !Path::new(self.target).exists() {
+    if !self.target.as_ref().exists() {
       return Ok(false);
     }
-    let output = String::from_utf8(self._run_in_target_repo(&["submodule", "status"])?)?;
+    let output = String::from_utf8(self._run_in_target_repo(args!["submodule", "status"])?)?;
     Ok(
       output
         .lines()
@@ -47,7 +49,7 @@ impl<'a, C: CommandRunner> Symbol for GitSubmodules<'a, C> {
   }
 
   fn execute(&self) -> Result<(), Box<dyn Error>> {
-    self._run_in_target_repo(&["submodule", "update", "--init"])?;
+    self._run_in_target_repo(args!["submodule", "update", "--init"])?;
     Ok(())
   }
 
diff --git a/src/symbols/mariadb/database.rs b/src/symbols/mariadb/database.rs
index 83cf8da..8861adf 100644
--- a/src/symbols/mariadb/database.rs
+++ b/src/symbols/mariadb/database.rs
@@ -1,18 +1,18 @@
-use std::borrow::Cow;
 use std::error::Error;
 use std::fmt;
+use std::path::Path;
 
 use command_runner::CommandRunner;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct MariaDBDatabase<'a, C: 'a + CommandRunner> {
-  db_name: Cow<'a, str>,
-  seed_file: Cow<'a, str>,
+pub struct MariaDBDatabase<'a, D: AsRef<str>, S: AsRef<Path>, C: CommandRunner> {
+  db_name: D,
+  seed_file: S,
   command_runner: &'a C,
 }
 
-impl<'a, C: CommandRunner> MariaDBDatabase<'a, C> {
-  pub fn new(db_name: Cow<'a, str>, seed_file: Cow<'a, str>, command_runner: &'a C) -> Self {
+impl<'a, D: AsRef<str>, S: AsRef<Path>, C: CommandRunner> MariaDBDatabase<'a, D, S, C> {
+  pub fn new(db_name: D, seed_file: S, command_runner: &'a C) -> Self {
     MariaDBDatabase {
       db_name,
       seed_file,
@@ -23,34 +23,40 @@ impl<'a, C: CommandRunner> MariaDBDatabase<'a, C> {
   fn run_sql(&self, sql: &str) -> Result<String, Box<dyn Error>> {
     let b = self
       .command_runner
-      .get_output("mariadb", &["--skip-column-names", "-B", "-e", sql])?;
+      .get_output("mariadb", args!["--skip-column-names", "-B", "-e", sql])?;
     Ok(String::from_utf8(b)?)
   }
 }
 
-impl<'a, C: CommandRunner> fmt::Display for MariaDBDatabase<'a, C> {
+impl<'a, D: AsRef<str>, S: AsRef<Path>, C: CommandRunner> fmt::Display
+  for MariaDBDatabase<'a, D, S, C>
+{
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "MariaDB Database {}", self.db_name)
+    write!(f, "MariaDB Database {}", self.db_name.as_ref())
   }
 }
 
-impl<'a, C: CommandRunner> Symbol for MariaDBDatabase<'a, C> {
+impl<'a, D: AsRef<str>, S: AsRef<Path>, C: CommandRunner> Symbol for MariaDBDatabase<'a, D, S, C> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     Ok(
       self
-        .run_sql(&format!("SHOW DATABASES LIKE '{}'", self.db_name))?
+        .run_sql(&format!("SHOW DATABASES LIKE '{}'", self.db_name.as_ref()))?
         .trim_end()
-        == self.db_name,
+        == self.db_name.as_ref(),
     )
   }
 
   fn execute(&self) -> Result<(), Box<dyn Error>> {
-    self.run_sql(&format!("CREATE DATABASE {}", self.db_name))?;
+    self.run_sql(&format!("CREATE DATABASE {}", self.db_name.as_ref()))?;
     self.command_runner.run_successfully(
       "sh",
-      &[
+      args![
         "-c",
-        &format!("mariadb '{}' < {}", self.db_name, self.seed_file),
+        format!(
+          "mariadb '{}' < {}",
+          self.db_name.as_ref(),
+          self.seed_file.as_ref().to_str().unwrap()
+        ),
       ],
     )
   }
diff --git a/src/symbols/mariadb/database_dump.rs b/src/symbols/mariadb/database_dump.rs
index 6577c6a..64d3f22 100644
--- a/src/symbols/mariadb/database_dump.rs
+++ b/src/symbols/mariadb/database_dump.rs
@@ -6,12 +6,7 @@ use command_runner::CommandRunner;
 use storage::Storage;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct DatabaseDump<'a, N, C, S>
-where
-  N: 'a + AsRef<str>,
-  C: 'a + CommandRunner,
-  S: Storage,
-{
+pub struct DatabaseDump<'a, N: AsRef<str>, C: CommandRunner, S: Storage> {
   db_name: N,
   storage: S,
   command_runner: &'a C,
@@ -29,7 +24,7 @@ impl<'a, N: AsRef<str>, C: CommandRunner, S: Storage> DatabaseDump<'a, N, C, S>
   fn run_sql(&self, sql: &str) -> Result<String, Box<dyn Error>> {
     let b = self
       .command_runner
-      .get_output("mariadb", &["--skip-column-names", "-B", "-e", sql])?;
+      .get_output("mariadb", args!["--skip-column-names", "-B", "-e", sql])?;
     Ok(String::from_utf8(b)?)
   }
 }
@@ -43,7 +38,7 @@ impl<'a, N: AsRef<str>, C: CommandRunner, S: Storage> fmt::Display for DatabaseD
 impl<'a, N: AsRef<str>, C: CommandRunner, S: Storage> Symbol for DatabaseDump<'a, N, C, S> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     let dump_date = self.storage.recent_date()?;
-    let modified_date = try!(self.run_sql(&format!("select UNIX_TIMESTAMP(MAX(UPDATE_TIME)) from information_schema.tables WHERE table_schema = '{}'", self.db_name.as_ref())));
+    let modified_date = self.run_sql(&format!("select UNIX_TIMESTAMP(MAX(UPDATE_TIME)) from information_schema.tables WHERE table_schema = '{}'", self.db_name.as_ref()))?;
     if modified_date.trim_end() == "NULL" {
       return Ok(false);
     }
@@ -53,9 +48,9 @@ impl<'a, N: AsRef<str>, C: CommandRunner, S: Storage> Symbol for DatabaseDump<'a
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     self.command_runner.run_successfully(
       "sh",
-      &[
+      args![
         "-c",
-        &format!(
+        format!(
           "mysqldump '{}' > {}",
           self.db_name.as_ref(),
           self.storage.write_filename()
diff --git a/src/symbols/mariadb/user.rs b/src/symbols/mariadb/user.rs
index ca923ab..9a6d4e0 100644
--- a/src/symbols/mariadb/user.rs
+++ b/src/symbols/mariadb/user.rs
@@ -1,4 +1,3 @@
-use std::borrow::Cow;
 use std::error::Error;
 use std::fmt;
 
@@ -6,13 +5,13 @@ use command_runner::CommandRunner;
 use resources::Resource;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct MariaDBUser<'a, C: 'a + CommandRunner> {
-  user_name: Cow<'a, str>,
+pub struct MariaDBUser<'a, U: AsRef<str>, C: CommandRunner> {
+  user_name: U,
   command_runner: &'a C,
 }
 
-impl<'a, C: CommandRunner> MariaDBUser<'a, C> {
-  pub fn new(user_name: Cow<'a, str>, command_runner: &'a C) -> Self {
+impl<'a, U: AsRef<str>, C: CommandRunner> MariaDBUser<'a, U, C> {
+  pub fn new(user_name: U, command_runner: &'a C) -> Self {
     MariaDBUser {
       user_name,
       command_runner,
@@ -22,40 +21,40 @@ impl<'a, C: CommandRunner> MariaDBUser<'a, C> {
   fn run_sql(&self, sql: &str) -> Result<String, Box<dyn Error>> {
     let b = self
       .command_runner
-      .get_output("mariadb", &["--skip-column-names", "-B", "-e", sql])?;
+      .get_output("mariadb", args!["--skip-column-names", "-B", "-e", sql])?;
     Ok(String::from_utf8(b)?)
   }
 }
 
-impl<'a, C: CommandRunner> fmt::Display for MariaDBUser<'a, C> {
+impl<'a, U: AsRef<str>, C: CommandRunner> fmt::Display for MariaDBUser<'a, U, C> {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "MariaDB User {}", self.user_name)
+    write!(f, "MariaDB User {}", self.user_name.as_ref())
   }
 }
 
-impl<'a, C: CommandRunner> Symbol for MariaDBUser<'a, C> {
+impl<'a, U: AsRef<str>, C: CommandRunner> Symbol for MariaDBUser<'a, U, C> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     Ok(
       self
         .run_sql(&format!(
           "SELECT User FROM mysql.user WHERE User = '{}' AND plugin = 'unix_socket'",
-          self.user_name
+          self.user_name.as_ref()
         ))?
         .trim_end()
-        == self.user_name,
+        == self.user_name.as_ref(),
     )
   }
 
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     self.run_sql(&format!(
       "GRANT ALL ON {0}.* TO {0} IDENTIFIED VIA unix_socket",
-      self.user_name
+      self.user_name.as_ref()
     ))?;
     Ok(())
   }
 
   fn get_prerequisites(&self) -> Vec<Resource> {
-    vec![Resource::new("user", self.user_name.to_string())]
+    vec![Resource::new("user", self.user_name.as_ref())]
   }
 
   fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
diff --git a/src/symbols/nginx/server.rs b/src/symbols/nginx/server.rs
index 75c67ec..97a82e0 100644
--- a/src/symbols/nginx/server.rs
+++ b/src/symbols/nginx/server.rs
@@ -1,7 +1,7 @@
 use std::error::Error;
 use std::fmt;
 use std::io;
-use std::ops::Deref;
+use std::path::{Path, PathBuf};
 
 use command_runner::CommandRunner;
 use resources::Resource;
@@ -41,16 +41,11 @@ impl<E: Error> fmt::Display for NginxServerError<E> {
   }
 }
 
-pub struct NginxServer<'a, C: 'a + CommandRunner, T>
-where
-  T: Deref<Target = str>,
-{
+pub struct NginxServer<'a, C: CommandRunner, T: AsRef<str>, P: AsRef<Path>> {
   command_runner: &'a C,
-  file: FileSymbol<T, String>,
+  file: FileSymbol<T, P>,
 }
 
-use std::borrow::Cow;
-
 pub fn server_config(domain: &str, content: &str) -> String {
   format!(
     "server {{
@@ -80,9 +75,9 @@ server {{
   )
 }
 
-pub fn php_server_config_snippet<'a>(
-  socket_path: Cow<'a, str>,
-  static_path: Cow<'a, str>,
+pub fn php_server_config_snippet<'a, SOCKET: AsRef<Path>, STATIC: AsRef<Path>>(
+  socket_path: SOCKET,
+  static_path: STATIC,
 ) -> String {
   format!(
     "
@@ -92,7 +87,8 @@ pub fn php_server_config_snippet<'a>(
       fastcgi_pass      unix:{};
       include           \"snippets/fastcgi-php.conf\";
     }}",
-    static_path, socket_path
+    static_path.as_ref().to_str().unwrap(),
+    socket_path.as_ref().to_str().unwrap()
   )
 }
 
@@ -100,9 +96,12 @@ pub trait SocketSpec {
   fn to_nginx(&self) -> String;
 }
 
-impl SocketSpec for &str {
+impl<T> SocketSpec for T
+where
+  T: AsRef<Path>,
+{
   fn to_nginx(&self) -> String {
-    format!("unix:{}:", self)
+    format!("unix:{}:", self.as_ref().to_str().unwrap())
   }
 }
 
@@ -120,7 +119,7 @@ impl SocketSpec for LocalTcpSocket {
   }
 }
 
-impl<'a, C: CommandRunner> NginxServer<'a, C, String> {
+impl<'a, C: CommandRunner> NginxServer<'a, C, String, PathBuf> {
   pub fn new_redir(domain: &'a str, target: &'a str, command_runner: &'a C) -> Self {
     let content = server_config(
       domain,
@@ -134,10 +133,10 @@ impl<'a, C: CommandRunner> NginxServer<'a, C, String> {
     NginxServer::new(domain, content, command_runner)
   }
 
-  pub fn new_proxy<S: SocketSpec>(
+  pub fn new_proxy<S: SocketSpec, STATIC: AsRef<Path>>(
     domain: &'a str,
     socket_path: S,
-    static_path: &'a str,
+    static_path: STATIC,
     command_runner: &'a C,
   ) -> Self {
     let proxy_content = format!(
@@ -160,16 +159,17 @@ location @proxy {{
     root                    {};
     {}
 ",
-        static_path, proxy_content
+        static_path.as_ref().to_str().unwrap(),
+        proxy_content
       ),
     );
     NginxServer::new(domain, content, command_runner)
   }
 
-  pub fn new_php(
+  pub fn new_php<SOCKET: AsRef<Path>, STATIC: AsRef<Path>>(
     domain: &'a str,
-    socket_path: Cow<'a, str>,
-    static_path: Cow<'a, str>,
+    socket_path: SOCKET,
+    static_path: STATIC,
     command_runner: &'a C,
     additional_config: &'a str,
   ) -> Self {
@@ -180,7 +180,11 @@ location @proxy {{
     NginxServer::new(domain, content, command_runner)
   }
 
-  pub fn new_static(domain: &'a str, static_path: &'a str, command_runner: &'a C) -> Self {
+  pub fn new_static<S: AsRef<Path>>(
+    domain: &'a str,
+    static_path: S,
+    command_runner: &'a C,
+  ) -> Self {
     let content = server_config(
       domain,
       &format!(
@@ -188,14 +192,14 @@ location @proxy {{
     root                    {};
     try_files $uri $uri/ $uri.html =404;
 ",
-        static_path
+        static_path.as_ref().to_str().unwrap()
       ),
     );
     NginxServer::new(domain, content, command_runner)
   }
 
   pub fn new(domain: &'a str, content: String, command_runner: &'a C) -> Self {
-    let file_path = String::from("/etc/nginx/sites-enabled/") + domain;
+    let file_path: PathBuf = ["/etc/nginx/sites-enabled/", domain].iter().collect();
     NginxServer {
       command_runner,
       file: FileSymbol::new(file_path, content),
@@ -203,10 +207,7 @@ location @proxy {{
   }
 }
 
-impl<'a, C: CommandRunner, T> Symbol for NginxServer<'a, C, T>
-where
-  T: Deref<Target = str>,
-{
+impl<'a, C: CommandRunner, T: AsRef<str>, P: AsRef<Path>> Symbol for NginxServer<'a, C, T, P> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     if !self.file.target_reached()? {
       return Ok(false);
@@ -219,7 +220,7 @@ where
     self.file.execute()?;
     self
       .command_runner
-      .run_successfully("systemctl", &["reload-or-restart", "nginx"])
+      .run_successfully("systemctl", args!["reload-or-restart", "nginx"])
   }
 
   fn get_prerequisites(&self) -> Vec<Resource> {
@@ -238,9 +239,8 @@ where
   }
 }
 
-impl<'a, C: CommandRunner, T> fmt::Display for NginxServer<'a, C, T>
-where
-  T: Deref<Target = str>,
+impl<'a, C: CommandRunner, T: AsRef<str>, P: AsRef<Path>> fmt::Display
+  for NginxServer<'a, C, T, P>
 {
   fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
     write!(f, "Nginx server config")
diff --git a/src/symbols/npm.rs b/src/symbols/npm.rs
index f573e74..0cfa3e4 100644
--- a/src/symbols/npm.rs
+++ b/src/symbols/npm.rs
@@ -5,13 +5,13 @@ use std::path::Path;
 use command_runner::CommandRunner;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct NpmInstall<'a, C: 'a + CommandRunner> {
-  target: &'a str,
+pub struct NpmInstall<'a, T: AsRef<Path>, C: CommandRunner> {
+  target: T,
   command_runner: &'a C,
 }
 
-impl<'a, C: CommandRunner> NpmInstall<'a, C> {
-  pub fn new(target: &'a str, command_runner: &'a C) -> Self {
+impl<'a, T: AsRef<Path>, C: CommandRunner> NpmInstall<'a, T, C> {
+  pub fn new(target: T, command_runner: &'a C) -> Self {
     NpmInstall {
       target,
       command_runner,
@@ -19,20 +19,28 @@ impl<'a, C: CommandRunner> NpmInstall<'a, C> {
   }
 }
 
-impl<'a, C: CommandRunner> fmt::Display for NpmInstall<'a, C> {
+impl<'a, T: AsRef<Path>, C: CommandRunner> fmt::Display for NpmInstall<'a, T, C> {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "npm install in {}", self.target)
+    write!(
+      f,
+      "npm install in {}",
+      self.target.as_ref().to_str().unwrap()
+    )
   }
 }
 
-impl<'a, C: CommandRunner> Symbol for NpmInstall<'a, C> {
+impl<'a, T: AsRef<Path>, C: CommandRunner> Symbol for NpmInstall<'a, T, C> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    if !Path::new(self.target).exists() {
+    if !self.target.as_ref().exists() {
       return Ok(false);
     }
-    let result = self
-      .command_runner
-      .run_with_args("sh", &["-c", &format!("cd '{}' && npm ls", self.target)])?;
+    let result = self.command_runner.run_with_args(
+      "sh",
+      args![
+        "-c",
+        format!("cd '{}' && npm ls", self.target.as_ref().to_str().unwrap()),
+      ],
+    )?;
     Ok(
       result.status.success()
         && !String::from_utf8(result.stdout)
@@ -44,11 +52,11 @@ impl<'a, C: CommandRunner> Symbol for NpmInstall<'a, C> {
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     self.command_runner.run_successfully(
       "sh",
-      &[
+      args![
         "-c",
-        &format!(
+        format!(
           "cd '{}' && npm install --production --unsafe-perm",
-          self.target
+          self.target.as_ref().to_str().unwrap()
         ),
       ],
     )
diff --git a/src/symbols/owner.rs b/src/symbols/owner.rs
index 29d7c5a..6196a62 100644
--- a/src/symbols/owner.rs
+++ b/src/symbols/owner.rs
@@ -1,5 +1,6 @@
-use std::borrow::{Borrow, Cow};
+
 use std::error::Error;
+
 use std::fmt;
 use std::fs;
 use std::os::unix::fs::MetadataExt;
@@ -11,20 +12,14 @@ use command_runner::CommandRunner;
 use resources::Resource;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct Owner<'a, C: 'a + CommandRunner, D>
-where
-  D: AsRef<str>,
-{
+pub struct Owner<'a, C: CommandRunner, D: AsRef<Path>, U: AsRef<str>> {
   path: D,
-  user_name: Cow<'a, str>,
+  user_name: U,
   command_runner: &'a C,
 }
 
-impl<'a, C: CommandRunner, D> Owner<'a, C, D>
-where
-  D: AsRef<str>,
-{
-  pub fn new(path: D, user_name: Cow<'a, str>, command_runner: &'a C) -> Self {
+impl<'a, C: CommandRunner, D: AsRef<Path>, U: AsRef<str>> Owner<'a, C, D, U> {
+  pub fn new(path: D, user_name: U, command_runner: &'a C) -> Self {
     Owner {
       path,
       user_name,
@@ -33,28 +28,25 @@ where
   }
 }
 
-impl<'a, C: CommandRunner, D> Symbol for Owner<'a, C, D>
-where
-  D: AsRef<str>,
-{
+impl<'a, C: CommandRunner, D: AsRef<Path>, U: AsRef<str>> Symbol for Owner<'a, C, D, U> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     if !Path::new(self.path.as_ref()).exists() {
       return Ok(false);
     }
     let actual_uid = fs::metadata(self.path.as_ref()).unwrap().uid();
-    let target_uid = get_user_by_name(self.user_name.borrow()).unwrap().uid();
+    let target_uid = get_user_by_name(self.user_name.as_ref()).unwrap().uid();
     Ok(actual_uid == target_uid)
   }
 
   fn execute(&self) -> Result<(), Box<dyn Error>> {
-    self.command_runner.run_successfully(
-      "chown",
-      &["-R", self.user_name.borrow(), self.path.as_ref()],
-    )
+    let uname: &str = self.user_name.as_ref();
+    self
+      .command_runner
+      .run_successfully("chown", args!["-R", uname, self.path.as_ref(),])
   }
 
   fn get_prerequisites(&self) -> Vec<Resource> {
-    vec![Resource::new("user", self.user_name.to_string())]
+    vec![Resource::new("user", self.user_name.as_ref())]
   }
 
   fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
@@ -69,11 +61,13 @@ where
   }
 }
 
-impl<'a, C: CommandRunner, D> fmt::Display for Owner<'a, C, D>
-where
-  D: AsRef<str>,
-{
+impl<'a, C: CommandRunner, D: AsRef<Path>, U: AsRef<str>> fmt::Display for Owner<'a, C, D, U> {
   fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-    write!(f, "Owner {} for {}", self.user_name, self.path.as_ref())
+    write!(
+      f,
+      "Owner {} for {}",
+      self.user_name.as_ref(),
+      self.path.as_ref().display()
+    )
   }
 }
diff --git a/src/symbols/postgresql/database.rs b/src/symbols/postgresql/database.rs
index 7439d12..57e6653 100644
--- a/src/symbols/postgresql/database.rs
+++ b/src/symbols/postgresql/database.rs
@@ -1,18 +1,17 @@
-use std::borrow::Cow;
 use std::error::Error;
 use std::fmt;
 
 use command_runner::CommandRunner;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct PostgreSQLDatabase<'a, C: 'a + CommandRunner> {
-  name: Cow<'a, str>,
-  seed_file: Cow<'a, str>,
+pub struct PostgreSQLDatabase<'a, N: AsRef<str>, S: AsRef<str>, C: CommandRunner> {
+  name: N,
+  seed_file: S,
   command_runner: &'a C,
 }
 
-impl<'a, C: CommandRunner> PostgreSQLDatabase<'a, C> {
-  pub fn new(name: Cow<'a, str>, seed_file: Cow<'a, str>, command_runner: &'a C) -> Self {
+impl<'a, N: AsRef<str>, S: AsRef<str>, C: CommandRunner> PostgreSQLDatabase<'a, N, S, C> {
+  pub fn new(name: N, seed_file: S, command_runner: &'a C) -> Self {
     PostgreSQLDatabase {
       name,
       seed_file,
@@ -23,52 +22,68 @@ impl<'a, C: CommandRunner> PostgreSQLDatabase<'a, C> {
   fn run_sql(&self, sql: &str) -> Result<String, Box<dyn Error>> {
     let b = self.command_runner.get_output(
       "su",
-      &["-", "postgres", "-c", &format!("psql -t -c \"{}\"", sql)],
+      args!["-", "postgres", "-c", format!("psql -t -c \"{}\"", sql)],
     )?;
     Ok(String::from_utf8(b)?)
   }
 }
 
-impl<'a, C: CommandRunner> fmt::Display for PostgreSQLDatabase<'a, C> {
+impl<'a, N: AsRef<str>, S: AsRef<str>, C: CommandRunner> fmt::Display
+  for PostgreSQLDatabase<'a, N, S, C>
+{
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "PostgreSQL Database {}", self.name)
+    write!(f, "PostgreSQL Database {}", self.name.as_ref())
   }
 }
 
-impl<'a, C: CommandRunner> Symbol for PostgreSQLDatabase<'a, C> {
+impl<'a, N: AsRef<str>, S: AsRef<str>, C: CommandRunner> Symbol
+  for PostgreSQLDatabase<'a, N, S, C>
+{
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     Ok(
       self
         .run_sql(&format!(
           "SELECT datname FROM pg_database WHERE datname LIKE '{}'",
-          self.name
+          self.name.as_ref()
         ))?
         .trim()
-        == self.name,
+        == self.name.as_ref(),
     )
   }
 
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     self.command_runner.run_successfully(
       "su",
-      &["-", "postgres", "-c", &format!("createuser {}", self.name)],
+      args![
+        "-",
+        "postgres",
+        "-c",
+        format!("createuser {}", self.name.as_ref())
+      ],
     )?;
     self.command_runner.run_successfully(
       "su",
-      &[
+      args![
         "-",
         "postgres",
         "-c",
-        &format!("createdb -E UTF8 -T template0 -O {} {0}", self.name),
+        format!(
+          "createdb -E UTF8 -T template0 -O {} {0}",
+          self.name.as_ref()
+        ),
       ],
     )?;
     self.command_runner.run_successfully(
       "su",
-      &[
+      args![
         "-",
         "postgres",
         "-c",
-        &format!("psql '{}' < {}", self.name, self.seed_file),
+        format!(
+          "psql '{}' < {}",
+          self.name.as_ref(),
+          self.seed_file.as_ref()
+        ),
       ],
     )
   }
diff --git a/src/symbols/postgresql/database_dump.rs b/src/symbols/postgresql/database_dump.rs
index 6577c6a..64d3f22 100644
--- a/src/symbols/postgresql/database_dump.rs
+++ b/src/symbols/postgresql/database_dump.rs
@@ -6,12 +6,7 @@ use command_runner::CommandRunner;
 use storage::Storage;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct DatabaseDump<'a, N, C, S>
-where
-  N: 'a + AsRef<str>,
-  C: 'a + CommandRunner,
-  S: Storage,
-{
+pub struct DatabaseDump<'a, N: AsRef<str>, C: CommandRunner, S: Storage> {
   db_name: N,
   storage: S,
   command_runner: &'a C,
@@ -29,7 +24,7 @@ impl<'a, N: AsRef<str>, C: CommandRunner, S: Storage> DatabaseDump<'a, N, C, S>
   fn run_sql(&self, sql: &str) -> Result<String, Box<dyn Error>> {
     let b = self
       .command_runner
-      .get_output("mariadb", &["--skip-column-names", "-B", "-e", sql])?;
+      .get_output("mariadb", args!["--skip-column-names", "-B", "-e", sql])?;
     Ok(String::from_utf8(b)?)
   }
 }
@@ -43,7 +38,7 @@ impl<'a, N: AsRef<str>, C: CommandRunner, S: Storage> fmt::Display for DatabaseD
 impl<'a, N: AsRef<str>, C: CommandRunner, S: Storage> Symbol for DatabaseDump<'a, N, C, S> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     let dump_date = self.storage.recent_date()?;
-    let modified_date = try!(self.run_sql(&format!("select UNIX_TIMESTAMP(MAX(UPDATE_TIME)) from information_schema.tables WHERE table_schema = '{}'", self.db_name.as_ref())));
+    let modified_date = self.run_sql(&format!("select UNIX_TIMESTAMP(MAX(UPDATE_TIME)) from information_schema.tables WHERE table_schema = '{}'", self.db_name.as_ref()))?;
     if modified_date.trim_end() == "NULL" {
       return Ok(false);
     }
@@ -53,9 +48,9 @@ impl<'a, N: AsRef<str>, C: CommandRunner, S: Storage> Symbol for DatabaseDump<'a
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     self.command_runner.run_successfully(
       "sh",
-      &[
+      args![
         "-c",
-        &format!(
+        format!(
           "mysqldump '{}' > {}",
           self.db_name.as_ref(),
           self.storage.write_filename()
diff --git a/src/symbols/stored_directory.rs b/src/symbols/stored_directory.rs
index 7ed933f..9ad5d18 100644
--- a/src/symbols/stored_directory.rs
+++ b/src/symbols/stored_directory.rs
@@ -1,4 +1,3 @@
-use std::borrow::{Borrow, Cow};
 use std::error::Error;
 use std::fmt;
 use std::fs;
@@ -17,21 +16,15 @@ pub enum StorageDirection {
   Save,
 }
 
-pub struct StoredDirectory<'a, S, C: 'a + CommandRunner>
-where
-  S: Storage,
-{
-  path: Cow<'a, str>,
+pub struct StoredDirectory<'a, P: AsRef<Path>, S: Storage, C: CommandRunner> {
+  path: P,
   storage: S,
   dir: StorageDirection,
   command_runner: &'a C,
 }
 
-impl<'a, S, C: CommandRunner> StoredDirectory<'a, S, C>
-where
-  S: Storage,
-{
-  pub fn new(path: Cow<'a, str>, storage: S, dir: StorageDirection, command_runner: &'a C) -> Self {
+impl<'a, P: AsRef<Path>, S: Storage, C: CommandRunner> StoredDirectory<'a, P, S, C> {
+  pub fn new(path: P, storage: S, dir: StorageDirection, command_runner: &'a C) -> Self {
     StoredDirectory {
       path,
       storage,
@@ -41,19 +34,20 @@ where
   }
 }
 
-impl<'a, S, C: CommandRunner> fmt::Display for StoredDirectory<'a, S, C>
-where
-  S: Storage,
+impl<'a, P: AsRef<Path>, S: Storage, C: CommandRunner> fmt::Display
+  for StoredDirectory<'a, P, S, C>
 {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "Stored directory {} ({:?})", self.path, self.dir)
+    write!(
+      f,
+      "Stored directory {} ({:?})",
+      self.path.as_ref().display(),
+      self.dir
+    )
   }
 }
 
-impl<'a, S, C: CommandRunner> Symbol for StoredDirectory<'a, S, C>
-where
-  S: Storage,
-{
+impl<'a, P: AsRef<Path>, S: Storage, C: CommandRunner> Symbol for StoredDirectory<'a, P, S, C> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     let metadata = fs::metadata(self.path.as_ref());
     // Check if dir exists
@@ -74,11 +68,11 @@ where
     let dump_date = self.storage.recent_date()?;
     let output = self.command_runner.get_output(
       "sh",
-      &[
+      args![
         "-c",
-        &format!(
+        format!(
           "find {} -printf '%T@\\n' | sort -r | head -n1 | grep '^[0-9]\\+' -o",
-          self.path
+          self.path.as_ref().to_str().unwrap()
         ),
       ],
     )?;
@@ -90,7 +84,7 @@ where
     } {
       let output = self.command_runner.run_with_args(
         "diff",
-        &["-rq", &self.storage.read_filename()?, self.path.borrow()],
+        args!["-rq", self.storage.read_filename()?, self.path.as_ref()],
       )?;
       match output.status.code() {
         Some(0) => Ok(true),
@@ -106,15 +100,15 @@ where
     if self.dir == StorageDirection::Load {
       self
         .command_runner
-        .run_successfully("rm", &["-rf", self.path.borrow()])?;
+        .run_successfully("rm", args!["-rf", self.path.as_ref()])?;
       self.command_runner.run_successfully(
         "cp",
-        &["-a", &self.storage.read_filename()?, self.path.borrow()],
+        args!["-a", self.storage.read_filename()?, self.path.as_ref()],
       )
     } else {
       self.command_runner.run_successfully(
         "cp",
-        &["-a", self.path.borrow(), &self.storage.write_filename()],
+        args!["-a", self.path.as_ref(), self.storage.write_filename()],
       )
     }
   }
@@ -123,8 +117,8 @@ where
     if self.dir == StorageDirection::Save {
       return vec![];
     }
-    if let Some(parent) = Path::new(self.path.as_ref()).parent() {
-      vec![Resource::new("dir", parent.to_string_lossy())]
+    if let Some(parent) = self.path.as_ref().parent() {
+      vec![Resource::new("dir", parent.to_str().unwrap())]
     } else {
       vec![]
     }
@@ -132,7 +126,10 @@ where
 
   fn provides(&self) -> Option<Vec<Resource>> {
     if self.dir == StorageDirection::Load {
-      Some(vec![Resource::new("dir", self.path.to_string())])
+      Some(vec![Resource::new(
+        "dir",
+        self.path.as_ref().to_str().unwrap(),
+      )])
     } else {
       None
     }
diff --git a/src/symbols/systemd/reload.rs b/src/symbols/systemd/reload.rs
index 106df23..650ab94 100644
--- a/src/symbols/systemd/reload.rs
+++ b/src/symbols/systemd/reload.rs
@@ -26,7 +26,7 @@ impl<'a, C: CommandRunner> Symbol for ReloadService<'a, C> {
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     self
       .command_runner
-      .run_successfully("systemctl", &["reload-or-restart", self.service])
+      .run_successfully("systemctl", args!["reload-or-restart", self.service])
   }
 
   fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
diff --git a/src/symbols/systemd/user_service.rs b/src/symbols/systemd/user_service.rs
index 72a2d58..fa976e9 100644
--- a/src/symbols/systemd/user_service.rs
+++ b/src/symbols/systemd/user_service.rs
@@ -1,8 +1,12 @@
+use std::borrow::Cow;
 use std::error::Error;
+use std::ffi::OsStr;
 use std::fmt;
 use std::fs;
 use std::io;
-use std::ops::Deref;
+
+use std::path::Path;
+use std::path::PathBuf;
 use std::process::Output;
 use std::thread::sleep;
 use std::time::Duration;
@@ -51,29 +55,23 @@ impl<E: Error> fmt::Display for UserServiceError<E> {
   }
 }
 
-pub struct UserService<'a, C, R>
-where
-  C: Deref<Target = str>,
-  R: CommandRunner,
-{
+pub struct UserService<'a, C: AsRef<str>, R: CommandRunner> {
+  socket_path: Cow<'a, Path>,
   service_name: &'a str,
-  user_name: &'a str,
+  user_name: Cow<'a, str>,
   command_runner: R,
-  file: FileSymbol<C, String>,
+  config: FileSymbol<C, PathBuf>,
 }
 
-impl<'a, R> UserService<'a, String, SetuidCommandRunner<'a, R>>
-where
-  R: CommandRunner,
-{
-  pub fn new_nodejs(
-    home: &'a str,
-    user_name: &'a str,
+impl<'a, R: CommandRunner> UserService<'a, String, SetuidCommandRunner<'a, R>> {
+  pub fn new_nodejs<'b: 'a>(
+    home: Cow<'a, Path>,
+    user_name: Cow<'a, str>,
     service_name: &'a str,
-    path: &'a str,
+    path: Cow<'a, Path>,
     command_runner: &'a R,
+    socket_path: Cow<'a, Path>,
   ) -> Self {
-    let port = format!("/var/tmp/{}-{}.socket", user_name, service_name);
     let content = format!(
       "[Service]
 Environment=NODE_ENV=production
@@ -91,39 +89,46 @@ Restart=always
 [Install]
 WantedBy=default.target
 ",
-      path, port
+      path.to_str().unwrap(),
+      socket_path.to_str().unwrap()
     );
-    UserService::new(home, user_name, service_name, command_runner, content)
+    UserService::new(
+      socket_path,
+      home,
+      user_name,
+      service_name,
+      command_runner,
+      content,
+    )
   }
 
   pub fn new(
-    home: &'a str,
-    user_name: &'a str,
+    socket_path: Cow<'a, Path>,
+    home: Cow<'a, Path>,
+    user_name: Cow<'a, str>,
     service_name: &'a str,
     command_runner: &'a R,
     content: String,
   ) -> Self {
-    let file_path = format!(
-      "{}/.config/systemd/user/{}.service",
-      home.trim_end(),
-      service_name
-    );
+    let config_path: PathBuf = [
+      home.as_ref(),
+      format!(".config/systemd/user/{}.service", service_name).as_ref(),
+    ]
+    .iter()
+    .collect();
 
     UserService {
+      socket_path,
       service_name,
-      user_name,
+      user_name: user_name.clone(),
       command_runner: SetuidCommandRunner::new(user_name, command_runner),
-      file: FileSymbol::new(file_path, content),
+      config: FileSymbol::new(config_path, content),
     }
   }
 }
 
-impl<'a, C, R> UserService<'a, C, R>
-where
-  C: Deref<Target = str>,
-  R: CommandRunner,
-{
-  fn systemctl_wait_for_dbus(&self, args: &[&str]) -> Result<String, Box<dyn Error>> {
+impl<'a, C: AsRef<str>, R: CommandRunner> UserService<'a, C, R> {
+  fn systemctl_wait_for_dbus(&self, args: &[&OsStr]) -> Result<String, Box<dyn Error>> {
     let mut tries = 5;
     loop {
       let result = self.command_runner.run_with_args("systemctl", args)?;
@@ -146,7 +151,7 @@ where
 
   fn check_if_service(&self) -> Result<bool, Box<dyn Error>> {
     loop {
-      let active_state = self.systemctl_wait_for_dbus(&[
+      let active_state = self.systemctl_wait_for_dbus(args![
         "--user",
         "show",
         "--property",
@@ -160,7 +165,7 @@ where
           return Err(Box::new(
             UserServiceError::ActivationFailed(self.command_runner.run_with_args(
               "journalctl",
-              &["--user", &format!("--user-unit={}", self.service_name)],
+              args!["--user", format!("--user-unit={}", self.service_name)],
             )) as UserServiceError<io::Error>,
           ))
         }
@@ -170,22 +175,18 @@ where
   }
 }
 
-impl<'a, C, R> Symbol for UserService<'a, C, R>
-where
-  C: Deref<Target = str>,
-  R: CommandRunner,
-{
+impl<'a, C: AsRef<str>, R: CommandRunner> Symbol for UserService<'a, C, R> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    if !(self.file.target_reached()?) {
+    if !(self.config.target_reached()?) {
       return Ok(false);
     }
     self.check_if_service()
   }
 
   fn execute(&self) -> Result<(), Box<dyn Error>> {
-    self.file.execute()?;
-    self.systemctl_wait_for_dbus(&["--user", "enable", self.service_name])?;
-    self.systemctl_wait_for_dbus(&["--user", "restart", self.service_name])?;
+    self.config.execute()?;
+    self.systemctl_wait_for_dbus(args!["--user", "enable", self.service_name])?;
+    self.systemctl_wait_for_dbus(args!["--user", "restart", self.service_name])?;
 
     if !(self.check_if_service()?) {
       return Err(Box::new(
@@ -193,8 +194,7 @@ where
       ));
     }
 
-    let file_name = format!("/var/tmp/{}-{}.socket", self.user_name, self.service_name);
-    fs::metadata(&file_name)
+    fs::metadata(&self.socket_path)
       .map(|_| ())
       .map_err(|e| Box::new(e) as Box<dyn Error>)
   }
@@ -204,7 +204,7 @@ where
       "file",
       format!("/var/lib/systemd/linger/{}", self.user_name),
     )];
-    r.extend(self.file.get_prerequisites().into_iter());
+    r.extend(self.config.get_prerequisites().into_iter());
     r
   }
 
@@ -220,11 +220,7 @@ where
   }
 }
 
-impl<'a, C, R> fmt::Display for UserService<'a, C, R>
-where
-  C: Deref<Target = str>,
-  R: CommandRunner,
-{
+impl<'a, C: AsRef<str>, R: CommandRunner> fmt::Display for UserService<'a, C, R> {
   fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
     write!(f, "Systemd user service unit for {}", self.service_name)
   }
diff --git a/src/symbols/systemd/user_session.rs b/src/symbols/systemd/user_session.rs
index 92c7e78..602403d 100644
--- a/src/symbols/systemd/user_session.rs
+++ b/src/symbols/systemd/user_session.rs
@@ -1,4 +1,3 @@
-use std::borrow::{Borrow, Cow};
 use std::error::Error;
 use std::fmt;
 use std::path::PathBuf;
@@ -33,13 +32,13 @@ impl<E: Error> fmt::Display for SystemdUserSessionError<E> {
   }
 }
 
-pub struct SystemdUserSession<'a, C: 'a + CommandRunner> {
-  user_name: Cow<'a, str>,
+pub struct SystemdUserSession<'a, U: AsRef<str>, C: CommandRunner> {
+  user_name: U,
   command_runner: &'a C,
 }
 
-impl<'a, C: CommandRunner> SystemdUserSession<'a, C> {
-  pub fn new(user_name: Cow<'a, str>, command_runner: &'a C) -> Self {
+impl<'a, U: AsRef<str>, C: CommandRunner> SystemdUserSession<'a, U, C> {
+  pub fn new(user_name: U, command_runner: &'a C) -> Self {
     SystemdUserSession {
       user_name,
       command_runner,
@@ -47,10 +46,10 @@ impl<'a, C: CommandRunner> SystemdUserSession<'a, C> {
   }
 }
 
-impl<'a, C: CommandRunner> Symbol for SystemdUserSession<'a, C> {
+impl<'a, U: AsRef<str>, C: CommandRunner> Symbol for SystemdUserSession<'a, U, C> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     let mut path = PathBuf::from("/var/lib/systemd/linger");
-    path.push(self.user_name.borrow() as &str);
+    path.push(self.user_name.as_ref());
     Ok(path.exists())
     // Could also do `loginctl show-user ${self.user_name} | grep -F 'Linger=yes`
   }
@@ -58,7 +57,7 @@ impl<'a, C: CommandRunner> Symbol for SystemdUserSession<'a, C> {
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     self
       .command_runner
-      .run_successfully("loginctl", &["enable-linger", self.user_name.borrow()])
+      .run_successfully("loginctl", args!["enable-linger", self.user_name.as_ref()])
   }
 
   fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
@@ -73,8 +72,8 @@ impl<'a, C: CommandRunner> Symbol for SystemdUserSession<'a, C> {
   }
 }
 
-impl<'a, C: CommandRunner> fmt::Display for SystemdUserSession<'a, C> {
+impl<'a, U: AsRef<str>, C: CommandRunner> fmt::Display for SystemdUserSession<'a, U, C> {
   fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-    write!(f, "Systemd user session for {}", self.user_name)
+    write!(f, "Systemd user session for {}", self.user_name.as_ref())
   }
 }
diff --git a/src/symbols/tls/csr.rs b/src/symbols/tls/csr.rs
index 4df226f..de9681c 100644
--- a/src/symbols/tls/csr.rs
+++ b/src/symbols/tls/csr.rs
@@ -1,7 +1,8 @@
 use std::borrow::Cow;
 use std::error::Error;
+use std::ffi::OsStr;
 use std::fmt;
-use std::path::Path;
+use std::path::PathBuf;
 
 use command_runner::CommandRunner;
 use resources::Resource;
@@ -20,12 +21,12 @@ impl<'a, C: CommandRunner> TlsCsr<'a, C> {
     }
   }
 
-  fn get_key_path(&self) -> String {
-    format!("/etc/ssl/private/{}.key", self.domain)
+  fn get_key_path(&self) -> PathBuf {
+    format!("/etc/ssl/private/{}.key", self.domain).into()
   }
 
-  fn get_csr_path(&self) -> String {
-    format!("/etc/ssl/local_certs/{}.csr", self.domain)
+  fn get_csr_path(&self) -> PathBuf {
+    format!("/etc/ssl/local_certs/{}.csr", self.domain).into()
   }
 }
 
@@ -37,13 +38,19 @@ impl<'a, C: CommandRunner> fmt::Display for TlsCsr<'a, C> {
 
 impl<'a, C: CommandRunner> Symbol for TlsCsr<'a, C> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    if !Path::new(&self.get_csr_path()).exists() {
+    if !self.get_csr_path().exists() {
       return Ok(false);
     }
 
     let output = self.command_runner.get_stderr(
       "openssl",
-      &["req", "-in", &self.get_csr_path(), "-noout", "-verify"],
+      &[
+        OsStr::new("req"),
+        "-in".as_ref(),
+        self.get_csr_path().as_ref(),
+        "-noout".as_ref(),
+        "-verify".as_ref(),
+      ],
     )?;
     Ok(output == b"verify OK\n")
   }
@@ -52,22 +59,22 @@ impl<'a, C: CommandRunner> Symbol for TlsCsr<'a, C> {
     self.command_runner.run_successfully(
       "openssl",
       &[
-        "req",
-        "-new",
-        "-sha256",
-        "-key",
-        &self.get_key_path(),
-        "-out",
-        &self.get_csr_path(),
-        "-subj",
-        &format!("/CN={}", self.domain),
+        OsStr::new("req"),
+        "-new".as_ref(),
+        "-sha256".as_ref(),
+        "-key".as_ref(),
+        self.get_key_path().as_ref(),
+        "-out".as_ref(),
+        self.get_csr_path().as_ref(),
+        "-subj".as_ref(),
+        format!("/CN={}", self.domain).as_ref(),
       ],
     )?;
     Ok(())
   }
 
   fn get_prerequisites(&self) -> Vec<Resource> {
-    vec![Resource::new("file", self.get_key_path())]
+    vec![Resource::new("file", self.get_key_path().to_str().unwrap())]
   }
 
   fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
diff --git a/src/symbols/tls/key.rs b/src/symbols/tls/key.rs
index d347963..f25c754 100644
--- a/src/symbols/tls/key.rs
+++ b/src/symbols/tls/key.rs
@@ -1,7 +1,8 @@
 use std::borrow::Cow;
 use std::error::Error;
+use std::ffi::OsStr;
 use std::fmt;
-use std::path::Path;
+use std::path::PathBuf;
 
 use command_runner::CommandRunner;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
@@ -19,8 +20,10 @@ impl<'a, C: CommandRunner> TlsKey<'a, C> {
     }
   }
 
-  fn get_path(&self) -> String {
-    format!("/etc/ssl/private/{}.key", self.domain)
+  fn get_path(&self) -> PathBuf {
+    ["/etc/ssl/private", &format!("{}.key", self.domain)]
+      .iter()
+      .collect()
   }
 
   fn get_bytes(&self) -> u32 {
@@ -36,13 +39,20 @@ impl<'a, C: CommandRunner> fmt::Display for TlsKey<'a, C> {
 
 impl<'a, C: CommandRunner> Symbol for TlsKey<'a, C> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    if !Path::new(&self.get_path()).exists() {
+    if !self.get_path().exists() {
       return Ok(false);
     }
 
     let output = self.command_runner.get_output(
       "openssl",
-      &["rsa", "-in", &self.get_path(), "-noout", "-check", "-text"],
+      &[
+        OsStr::new("rsa"),
+        "-in".as_ref(),
+        self.get_path().as_ref(),
+        "-noout".as_ref(),
+        "-check".as_ref(),
+        "-text".as_ref(),
+      ],
     )?;
     Ok(output.starts_with(&format!("Private-Key: ({} bit)\n", self.get_bytes()).as_bytes()))
   }
@@ -51,10 +61,10 @@ impl<'a, C: CommandRunner> Symbol for TlsKey<'a, C> {
     self.command_runner.run_successfully(
       "openssl",
       &[
-        "genrsa",
-        "-out",
-        &self.get_path(),
-        &self.get_bytes().to_string(),
+        OsStr::new("genrsa"),
+        "-out".as_ref(),
+        self.get_path().as_ref(),
+        self.get_bytes().to_string().as_ref(),
       ],
     )
   }
diff --git a/src/symbols/tls/self_signed_cert.rs b/src/symbols/tls/self_signed_cert.rs
index cf09fea..059c154 100644
--- a/src/symbols/tls/self_signed_cert.rs
+++ b/src/symbols/tls/self_signed_cert.rs
@@ -1,57 +1,56 @@
-use std::borrow::Cow;
 use std::error::Error;
 use std::fmt;
-use std::path::Path;
+use std::path::PathBuf;
 
 use command_runner::CommandRunner;
 use resources::Resource;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct SelfSignedTlsCert<'a, C: 'a + CommandRunner> {
-  domain: Cow<'a, str>,
+pub struct SelfSignedTlsCert<'a, D: AsRef<str>, C: CommandRunner> {
+  domain: D,
   command_runner: &'a C,
 }
 
-impl<'a, C: CommandRunner> SelfSignedTlsCert<'a, C> {
-  pub fn new(domain: Cow<'a, str>, command_runner: &'a C) -> Self {
+impl<'a, D: AsRef<str>, C: CommandRunner> SelfSignedTlsCert<'a, D, C> {
+  pub fn new(domain: D, command_runner: &'a C) -> Self {
     SelfSignedTlsCert {
       domain,
       command_runner,
     }
   }
 
-  fn get_key_path(&self) -> String {
-    format!("/etc/ssl/private/{}.key", self.domain)
+  fn get_key_path(&self) -> PathBuf {
+    format!("/etc/ssl/private/{}.key", self.domain.as_ref()).into()
   }
 
-  fn get_cert_path(&self) -> String {
-    format!("/etc/ssl/local_certs/{}.chained.crt", self.domain)
+  fn get_cert_path(&self) -> PathBuf {
+    format!("/etc/ssl/local_certs/{}.chained.crt", self.domain.as_ref()).into()
   }
 }
 
-impl<'a, C: CommandRunner> fmt::Display for SelfSignedTlsCert<'a, C> {
+impl<'a, D: AsRef<str>, C: CommandRunner> fmt::Display for SelfSignedTlsCert<'a, D, C> {
   fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-    write!(f, "SelfSignedTlsCert {}", self.domain)
+    write!(f, "SelfSignedTlsCert {}", self.domain.as_ref())
   }
 }
 
 const DAYS_IN_SECONDS: u32 = 24 * 60 * 60;
 
-impl<'a, C: CommandRunner> Symbol for SelfSignedTlsCert<'a, C> {
+impl<'a, D: AsRef<str>, C: CommandRunner> Symbol for SelfSignedTlsCert<'a, D, C> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    if !Path::new(&self.get_cert_path()).exists() {
+    if !self.get_cert_path().exists() {
       return Ok(false);
     }
     let output = self.command_runner.run_with_args(
       "openssl",
-      &[
+      args![
         "x509",
         "-in",
-        &self.get_cert_path(),
+        self.get_cert_path(),
         "-noout",
         "-subject",
         "-checkend",
-        &(30 * DAYS_IN_SECONDS).to_string(),
+        (30 * DAYS_IN_SECONDS).to_string(),
       ],
     )?;
     println!("{}", output.status.code().unwrap());
@@ -60,13 +59,17 @@ impl<'a, C: CommandRunner> Symbol for SelfSignedTlsCert<'a, C> {
         output.stdout
           == format!(
             "subject=CN = {}\nCertificate will not expire\n",
-            self.domain
+            self.domain.as_ref()
           )
           .as_bytes(),
       ),
       Some(_) => {
         if output.stdout
-          == format!("subject=CN = {}\nCertificate will expire\n", self.domain).as_bytes()
+          == format!(
+            "subject=CN = {}\nCertificate will expire\n",
+            self.domain.as_ref()
+          )
+          .as_bytes()
         {
           Ok(false)
         } else {
@@ -80,24 +83,24 @@ impl<'a, C: CommandRunner> Symbol for SelfSignedTlsCert<'a, C> {
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     self.command_runner.run_successfully(
       "openssl",
-      &[
+      args![
         "req",
         "-x509",
         "-sha256",
         "-days",
         "90",
         "-key",
-        &self.get_key_path(),
+        self.get_key_path(),
         "-out",
-        &self.get_cert_path(),
+        self.get_cert_path(),
         "-subj",
-        &format!("/CN={}", self.domain),
+        format!("/CN={}", self.domain.as_ref()),
       ],
     )
   }
 
   fn get_prerequisites(&self) -> Vec<Resource> {
-    vec![Resource::new("file", self.get_key_path())]
+    vec![Resource::new("file", self.get_key_path().to_str().unwrap())]
   }
 
   fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
diff --git a/src/symbols/user.rs b/src/symbols/user.rs
index f2524c5..4b29501 100644
--- a/src/symbols/user.rs
+++ b/src/symbols/user.rs
@@ -69,7 +69,7 @@ impl fmt::Display for UserError {
   }
 }
 
-pub struct User<'a, C: 'a + CommandRunner, A: 'a + UserAdder> {
+pub struct User<'a, C: CommandRunner, A: UserAdder> {
   user_name: Cow<'a, str>,
   command_runner: &'a C,
   user_adder: &'a A,
@@ -95,7 +95,7 @@ impl<'a, C: CommandRunner, A: 'a + UserAdder> Symbol for User<'a, C, A> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     let output = self
       .command_runner
-      .run_with_args("getent", &["passwd", &*self.user_name])?;
+      .run_with_args("getent", args!["passwd", self.user_name.as_ref()])?;
     match output.status.code() {
       Some(2) => Ok(false),
       Some(0) => Ok(true),
@@ -106,12 +106,12 @@ impl<'a, C: CommandRunner, A: 'a + UserAdder> Symbol for User<'a, C, A> {
   fn execute(&self) -> Result<(), Box<dyn Error>> {
     self
       .user_adder
-      .add_user(&*self.user_name)
+      .add_user(self.user_name.as_ref())
       .map_err(|e| Box::new(e) as Box<dyn Error>)
   }
 
   fn provides(&self) -> Option<Vec<Resource>> {
-    Some(vec![Resource::new("user", self.user_name.to_string())])
+    Some(vec![Resource::new("user", self.user_name.to_owned())])
   }
 
   fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
@@ -140,7 +140,7 @@ impl<'a, C: CommandRunner> UserAdder for SystemUserAdder<'a, C> {
   fn add_user(&self, user_name: &str) -> Result<(), UserAdderError> {
     let output = self.command_runner.run_with_args(
       "adduser",
-      &[
+      args![
         // "-m", // Necessary for Fedora, not accepted in Debian
         "--system", user_name,
       ],
diff --git a/src/symbols/wordpress/plugin.rs b/src/symbols/wordpress/plugin.rs
index 0f2fe79..23230c0 100644
--- a/src/symbols/wordpress/plugin.rs
+++ b/src/symbols/wordpress/plugin.rs
@@ -4,29 +4,20 @@ use std::fmt;
 use std::fs::File as FsFile;
 use std::io;
 use std::io::{BufRead, BufReader};
-use std::ops::Deref;
 use std::path::{Path, PathBuf};
 
 use command_runner::CommandRunner;
 use resources::Resource;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct WordpressPlugin<'a, C, R>
-where
-  C: Deref<Target = str>,
-  R: 'a + CommandRunner,
-{
-  base: C,
-  name: C,
+pub struct WordpressPlugin<'a, P: AsRef<Path>, N: AsRef<str>, R: CommandRunner> {
+  base: P,
+  name: N,
   command_runner: &'a R,
 }
 
-impl<'a, C, R> WordpressPlugin<'a, C, R>
-where
-  C: Deref<Target = str>,
-  R: CommandRunner,
-{
-  pub fn new(base: C, name: C, command_runner: &'a R) -> Self {
+impl<'a, P: AsRef<Path>, N: AsRef<str>, R: CommandRunner> WordpressPlugin<'a, P, N, R> {
+  pub fn new(base: P, name: N, command_runner: &'a R) -> Self {
     WordpressPlugin {
       base,
       name,
@@ -35,22 +26,21 @@ where
   }
 
   fn get_path(&self) -> PathBuf {
-    Path::new(&*self.base)
+    self
+      .base
+      .as_ref()
       .join("wp-content/plugins")
-      .join(&*self.name)
+      .join(self.name.as_ref())
   }
 }
 
-impl<'a, C, R> Symbol for WordpressPlugin<'a, C, R>
-where
-  C: Deref<Target = str>,
-  R: CommandRunner,
-{
+impl<'a, P: AsRef<Path>, N: AsRef<str>, R: CommandRunner> Symbol for WordpressPlugin<'a, P, N, R> {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
-    if !self.get_path().exists() {
+    let base_path = self.get_path();
+    if !base_path.exists() {
       return Ok(false);
     }
-    let path = self.get_path().join(self.name.to_string() + ".php");
+    let path = base_path.join(self.name.as_ref().to_owned() + ".php");
     let mut version = String::new();
     let mut plugin_uri = String::new();
     match FsFile::open(path) {
@@ -78,11 +68,13 @@ where
     }
     let upstream = self.command_runner.get_output(
       "curl",
-      &[
+      args![
         "--form",
-        &format!(
+        format!(
           r###"plugins={{"plugins":{{"{0}/{0}.php":{{"Version":"{1}", "PluginURI":"{2}"}}}}}}"###,
-          &*self.name, version, plugin_uri
+          self.name.as_ref(),
+          version,
+          plugin_uri
         ),
         "https://api.wordpress.org/plugins/update-check/1.1/",
       ],
@@ -91,23 +83,20 @@ where
   }
 
   fn execute(&self) -> Result<(), Box<dyn Error>> {
-    let source = format!("https://downloads.wordpress.org/plugin/{}.zip", &*self.name);
-    let zip = format!("/tmp/{}.zip", &*self.name);
+    let source = format!(
+      "https://downloads.wordpress.org/plugin/{}.zip",
+      self.name.as_ref()
+    );
+    let zip = format!("/tmp/{}.zip", self.name.as_ref());
     self
       .command_runner
-      .run_successfully("curl", &[source.as_ref() as &str, "-o", zip.as_ref()])?;
+      .run_successfully("curl", args![source, "-o", zip])?;
     self
       .command_runner
-      .run_successfully("rm", &["-rf", &self.get_path().to_string_lossy()])?;
+      .run_successfully("rm", args!["-rf", self.get_path()])?;
     self.command_runner.run_successfully(
       "unzip",
-      &[
-        zip.as_ref(),
-        "-d".as_ref(),
-        Path::new(&*self.base)
-          .join("wp-content/plugins")
-          .as_os_str(),
-      ],
+      args![zip, "-d", self.base.as_ref().join("wp-content/plugins")],
     )
   }
 
@@ -130,12 +119,10 @@ where
   }
 }
 
-impl<'a, C, R> fmt::Display for WordpressPlugin<'a, C, R>
-where
-  C: Deref<Target = str>,
-  R: CommandRunner,
+impl<'a, P: AsRef<Path>, N: AsRef<str>, R: CommandRunner> fmt::Display
+  for WordpressPlugin<'a, P, N, R>
 {
   fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-    write!(f, "WordpressPlugin {}", &*self.name)
+    write!(f, "WordpressPlugin {}", self.name.as_ref())
   }
 }
diff --git a/src/symbols/wordpress/translation.rs b/src/symbols/wordpress/translation.rs
index dcf6f22..469406d 100644
--- a/src/symbols/wordpress/translation.rs
+++ b/src/symbols/wordpress/translation.rs
@@ -1,39 +1,31 @@
 use regex::Regex;
 use std::cmp::max;
 use std::error::Error;
+
 use std::fmt;
 use std::fs::File as FsFile;
 use std::io;
 use std::io::{BufRead, BufReader};
 use std::path::Path;
+use std::path::PathBuf;
 
 use command_runner::CommandRunner;
 use resources::Resource;
 use symbols::{Action, OwnedSymbolAction, Symbol, SymbolAction, SymbolRunner};
 
-pub struct WordpressTranslation<'a, C, D, R>
-where
-  C: AsRef<str>,
-  D: AsRef<str>,
-  R: 'a + CommandRunner,
-{
+pub struct WordpressTranslation<'a, C: AsRef<str>, D: AsRef<Path>, R: CommandRunner> {
   path: D,
   version: &'a str,
   locale: C,
   command_runner: &'a R,
 }
 
-impl<'a, C, R> WordpressTranslation<'a, C, String, R>
-where
-  C: AsRef<str>,
-  R: CommandRunner,
-{
-  pub fn new<D: AsRef<str>>(path: D, version: &'a str, locale: C, command_runner: &'a R) -> Self {
+impl<'a, C: AsRef<str>, R: CommandRunner> WordpressTranslation<'a, C, PathBuf, R> {
+  pub fn new<D: AsRef<Path>>(path: D, version: &'a str, locale: C, command_runner: &'a R) -> Self {
     WordpressTranslation {
-      path: Path::new(path.as_ref())
-        .join("wp-content/languages")
-        .to_string_lossy()
-        .to_string(),
+      path: [path.as_ref(), "wp-content/languages".as_ref()]
+        .iter()
+        .collect(),
       version,
       locale,
       command_runner,
@@ -41,19 +33,14 @@ where
   }
 }
 
-impl<'a, C, D, R> WordpressTranslation<'a, C, D, R>
-where
-  C: AsRef<str>,
-  D: AsRef<str>,
-  R: CommandRunner,
-{
-  fn get_pairs(&self) -> Vec<(String, String)> {
+impl<'a, C: AsRef<str>, D: AsRef<Path>, R: CommandRunner> WordpressTranslation<'a, C, D, R> {
+  fn get_pairs(&self) -> Vec<(String, PathBuf)> {
     let version_x = self
       .version
       .trim_end_matches(|c: char| c.is_digit(10))
       .to_owned()
       + "x";
-    let locale: &str = self.locale.as_ref();
+    let locale = self.locale.as_ref();
     let path_locale = if locale == "de_DE" {
       "de".to_owned()
     } else {
@@ -71,7 +58,7 @@ where
       for format in ["po", "mo"].iter() {
         res.push((
           format!("https://translate.wordpress.org/projects/wp/{}/{}{}/default/export-translations?format={}", version_x, in_slug, path_locale, format),
-          format!("{}/{}{}.{}", self.path.as_ref(), out_slug, self.locale.as_ref(), format)
+          [self.path.as_ref(), format!("{}{}.{}", out_slug, self.locale.as_ref(), format).as_ref()].iter().collect()
         ))
       }
     }
@@ -79,11 +66,8 @@ where
   }
 }
 
-impl<'a, C, D, R> Symbol for WordpressTranslation<'a, C, D, R>
-where
-  C: AsRef<str>,
-  D: AsRef<str>,
-  R: CommandRunner,
+impl<'a, C: AsRef<str>, D: AsRef<Path>, R: CommandRunner> Symbol
+  for WordpressTranslation<'a, C, D, R>
 {
   fn target_reached(&self) -> Result<bool, Box<dyn Error>> {
     let mut newest = String::new();
@@ -113,7 +97,7 @@ where
     }
     let upstream = self.command_runner.get_output(
       "curl",
-      &[&format!(
+      args![format!(
         "https://api.wordpress.org/core/version-check/1.7/?version={}&locale={}",
         self.version,
         self.locale.as_ref()
@@ -131,13 +115,13 @@ where
     for (source, target) in self.get_pairs() {
       self
         .command_runner
-        .run_successfully("curl", &["--compressed", "-o", &target, &source])?;
+        .run_successfully("curl", args!["--compressed", "-o", target, source,])?;
     }
     Ok(())
   }
 
   fn get_prerequisites(&self) -> Vec<Resource> {
-    vec![Resource::new("dir", self.path.as_ref())]
+    vec![Resource::new("dir", self.path.as_ref().to_str().unwrap())]
   }
 
   fn as_action<'b>(&'b self, runner: &'b dyn SymbolRunner) -> Box<dyn Action + 'b> {
@@ -152,13 +136,10 @@ where
   }
 }
 
-impl<'a, C, D, R> fmt::Display for WordpressTranslation<'a, C, D, R>
-where
-  C: AsRef<str>,
-  D: AsRef<str>,
-  R: CommandRunner,
+impl<'a, C: AsRef<str>, D: AsRef<Path>, R: CommandRunner> fmt::Display
+  for WordpressTranslation<'a, C, D, R>
 {
   fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-    write!(f, "WordpressTranslation {}", self.path.as_ref())
+    write!(f, "WordpressTranslation {}", self.path.as_ref().display())
   }
 }