Add function systemd::systemd_escape (#243)

* Add function systemd::systemd_escape

* Add function systemd::systemd_escape

* disable combine

* trim value

* fix tests

* Mock systemd

* Update README.md

Co-authored-by: Ewoud Kohl van Wijngaarden <ewoud@kohlvanwijngaarden.nl>

* Optimize unit tests

* Remove lint issues

Co-authored-by: Ewoud Kohl van Wijngaarden <ewoud@kohlvanwijngaarden.nl>

Author: jkroepke

README.md

@@ -423,7 +423,9 @@ loginctl_user { 'foo':
 or as a hash via the `systemd::loginctl_users` parameter.
 
 ### Systemd Escape Function
-Escapes strings as `systemd-escape` command does.
+Partially escape strings as `systemd-escape` command does.
+
+This functions only escapes a subset of chars. Non-ASCII character will not escape.
 
 ```puppet
 $result = systemd::escape('foo::bar/')
@@ -437,6 +439,23 @@ $result = systemd::escape('/mnt/foobar/', true)
 ```
 `$result` would be `mnt-foobar`.
 
+### Systemd Escape Function (uses systemd-escape)
+Escape strings by call the `systemd-escape` command in the background.
+
+It's highly recommend running the function as [deferred function](https://puppet.com/docs/puppet/6/deferring_functions.html) since it executes the command on the agent.
+
+```puppet
+$result = Deferred('systemd::systemd_escape', ["foo::bar"])
+```
+`$result` would be `foo::bar-`
+
+or path escape as if with `-p` option.
+
+```puppet
+$result = Deferred('systemd::systemd_escape', ["/mnt/foo-bar/", true])
+```
+`$result` would be `mnt-foo\x2dbar`.
+
 ## Transfer Notice
 
 This plugin was originally authored by [Camptocamp](http://www.camptocamp.com).

lib/puppet/functions/systemd/systemd_escape.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+# @summary Escape strings by call the `systemd-escape` command in the background.
+Puppet::Functions.create_function(:'systemd::systemd_escape') do
+  # @param input Input string
+  # @param path Use path (-p) ornon-path  style escaping.
+  dispatch :escape do
+    param 'String', :input
+    optional_param 'Optional[Boolean]', :path
+    return_type 'String'
+  end
+
+  def escape(input, path = false)
+    args = []
+
+    args.push('--path') if path
+
+    args.push(input)
+    exec_systemd(args)
+  end
+
+  def exec_systemd(*args)
+    exec_args = { failonfail: true, combine: false }
+    escaped = Puppet::Util::Execution.execute(['systemd-escape', args], **exec_args)
+    escaped.strip
+  end
+end

spec/functions/systemd_escape_spec.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+describe 'systemd::systemd_escape' do
+  context 'with path false' do
+    it do
+      allow(Puppet::Util::Execution).to receive(:execute).with(['systemd-escape', [['abcöäüß']]], { combine: false, failonfail: true }).and_return("abc\\xc3\\xb6\\xc3\\xa4\\xc3\\xbc\\xc3\\x9f\n")
+
+      is_expected.to run.with_params('abcöäüß', false).and_return('abc\xc3\xb6\xc3\xa4\xc3\xbc\xc3\x9f')
+    end
+  end
+
+  context 'with path true' do
+    it do
+      allow(Puppet::Util::Execution).to receive(:execute).with(['systemd-escape', [%w[--path abcöäüß]]], { combine: false, failonfail: true }).and_return("abc\\xc3\\xb6\\xc3\\xa4\\xc3\\xbc\\xc3\\x9f\n")
+
+      is_expected.to run.with_params('abcöäüß', true).and_return('abc\xc3\xb6\xc3\xa4\xc3\xbc\xc3\x9f')
+    end
+  end
+end