Add a socket_service definition

For systemd socket activated services it's needed to have both the
.socket and .service unit defintions in place when starting the service.
Prior to 97dd16f the systemctl
daemon-reload took care of it, but now this must be done explicitly.

This new defined type makes it easy and reduces the burden on modules
that define the unit/service pair.

manifests/socket_service.pp

@@ -0,0 +1,61 @@
+# @summary Create a systemd socket activated service
+# @api public
+#
+# Systemd socket activated services have their own dependencies. This is a
+# convenience wrapper around systemd::unit_file.
+#
+# @param name [Pattern['^[^/]+$']]
+#   The target unit file to create
+# @param socket_content
+#   The content for the socket unit file. Required if ensure isn't absent.
+# @param service_content
+#   The content for the service unit file. Required if ensure isn't absent.
+# @param enable
+#   Whether to enable or disable the service. By default this is derived from
+#   $ensure but can be overridden for advanced use cases where the service is
+#   running during a migration but shouldn't be enabled on boot.
+define systemd::socket_service (
+  Enum['running', 'stopped', 'present', 'absent'] $ensure = 'running',
+  Optional[String[1]] $socket_content = undef,
+  Optional[String[1]] $service_content = undef,
+  Optional[Boolean] $enable = undef,
+) {
+  assert_type(Pattern['^[^/]+$'], $name)
+
+  if $ensure != 'absent' {
+    assert_type(NotUndef, $socket_content)
+    assert_type(NotUndef, $service_content)
+  }
+
+  $active = $ensure ? {
+    'running' => true,
+    'stopped' => false,
+    'absent'  => false,
+    default   => undef,
+  }
+  $real_enable = pick_default($enable, $active)
+
+  $unit_file_ensure = bool2str($ensure == 'absent', 'absent', 'present')
+
+  systemd::unit_file { "${name}.socket":
+    ensure  => $unit_file_ensure,
+    content => $socket_content,
+    active  => $active,
+    enable  => $real_enable,
+  }
+
+  systemd::unit_file { "${name}.service":
+    ensure  => $unit_file_ensure,
+    content => $service_content,
+    active  => $active,
+    enable  => $real_enable,
+  }
+
+  if $active or $real_enable {
+    # Systemd needs both .socket and .service to be loaded when starting the
+    # service. The unit_file takes care of matching, this ensures the
+    # non-matching order.
+    File["/etc/systemd/system/${name}.socket"] -> Service["${name}.service"]
+    File["/etc/systemd/system/${name}.service"] -> Service["${name}.socket"]
+  }
+}

spec/defines/socket_service_spec.rb

@@ -0,0 +1,187 @@
+require 'spec_helper'
+
+describe 'systemd::socket_service' do
+  let(:title) { 'myservice' }
+
+  on_supported_os.each do |os, os_facts|
+    context "on #{os}" do
+      let(:facts) { os_facts }
+
+      context 'ensure => running' do
+        let(:params) do
+          {
+            ensure: 'running',
+            socket_content: "[Socket]\nListenStream=/run/myservice.socket\n",
+            service_content: "[Service]\nType=notify\n",
+          }
+        end
+
+        it { is_expected.to compile.with_all_deps }
+        it 'sets up the socket unit file' do
+          is_expected.to contain_file('/etc/systemd/system/myservice.socket')
+            .with_ensure('file')
+            .with_content(%r{\[Socket\]})
+            .that_comes_before(['Service[myservice.socket]', 'Service[myservice.service]'])
+        end
+        it 'sets up the socket service' do
+          is_expected.to contain_service('myservice.socket')
+            .with_ensure(true)
+            .with_enable(true)
+        end
+        it 'sets up the service unit file' do
+          is_expected.to contain_file('/etc/systemd/system/myservice.service')
+            .with_ensure('file')
+            .with_content(%r{\[Service\]})
+            .that_comes_before('Service[myservice.service]')
+        end
+        it 'sets up the service service' do
+          is_expected.to contain_service('myservice.service')
+            .with_ensure(true)
+            .with_enable(true)
+        end
+
+        context 'enable => false' do
+          let(:params) { super().merge(enable: false) }
+
+          it { is_expected.to compile.with_all_deps }
+          it 'sets up the socket service' do
+            is_expected.to contain_service('myservice.socket')
+              .with_ensure(true)
+              .with_enable(false)
+          end
+          it 'sets up the service service' do
+            is_expected.to contain_service('myservice.service')
+              .with_ensure(true)
+              .with_enable(false)
+          end
+        end
+      end
+
+      context 'ensure => stopped' do
+        let(:params) do
+          {
+            ensure: 'stopped',
+            socket_content: "[Socket]\nListenStream=/run/myservice.socket\n",
+            service_content: "[Service]\nType=notify\n",
+          }
+        end
+
+        it { is_expected.to compile.with_all_deps }
+        it 'sets up the socket unit file' do
+          is_expected.to contain_file('/etc/systemd/system/myservice.socket')
+            .with_ensure('file')
+            .with_content(%r{\[Socket\]})
+            .that_comes_before(['Service[myservice.socket]', 'Service[myservice.service]'])
+        end
+        it 'sets up the socket service' do
+          is_expected.to contain_service('myservice.socket')
+            .with_ensure(false)
+            .with_enable(false)
+        end
+        it 'sets up the service unit file' do
+          is_expected.to contain_file('/etc/systemd/system/myservice.service')
+            .with_ensure('file')
+            .with_content(%r{\[Service\]})
+            .that_comes_before('Service[myservice.service]')
+        end
+        it 'sets up the service service' do
+          is_expected.to contain_service('myservice.service')
+            .with_ensure(false)
+            .with_enable(false)
+        end
+
+        context 'enable => true' do
+          let(:params) { super().merge(enable: true) }
+
+          it { is_expected.to compile.with_all_deps }
+          it 'sets up the socket service' do
+            is_expected.to contain_service('myservice.socket')
+              .with_ensure(false)
+              .with_enable(true)
+          end
+          it 'sets up the service service' do
+            is_expected.to contain_service('myservice.service')
+              .with_ensure(false)
+              .with_enable(true)
+          end
+        end
+      end
+
+      context 'ensure => present' do
+        let(:params) do
+          {
+            ensure: 'present',
+            socket_content: "[Socket]\nListenStream=/run/myservice.socket\n",
+            service_content: "[Service]\nType=notify\n",
+          }
+        end
+
+        it { is_expected.to compile.with_all_deps }
+        it 'sets up the socket unit file' do
+          is_expected.to contain_file('/etc/systemd/system/myservice.socket')
+            .with_ensure('file')
+            .with_content(%r{\[Socket\]})
+        end
+        it "doesn't set up the socket service" do
+          is_expected.not_to contain_service('myservice.socket')
+        end
+        it 'sets up the service unit file' do
+          is_expected.to contain_file('/etc/systemd/system/myservice.service')
+            .with_ensure('file')
+            .with_content(%r{\[Service\]})
+        end
+        it "doesn't set up the service service" do
+          is_expected.not_to contain_service('myservice.service')
+        end
+
+        context 'enable => true' do
+          let(:params) { super().merge(enable: true) }
+
+          it { is_expected.to compile.with_all_deps }
+          it 'sets up the socket service' do
+            is_expected.to contain_service('myservice.socket')
+              .without_ensure
+              .with_enable(true)
+          end
+          it 'sets up the service service' do
+            is_expected.to contain_service('myservice.service')
+              .without_ensure
+              .with_enable(true)
+          end
+        end
+      end
+
+      context 'ensure => absent' do
+        let(:params) do
+          {
+            ensure: 'absent',
+          }
+        end
+
+        it { is_expected.to compile.with_all_deps }
+        it 'sets up the socket unit file' do
+          is_expected.to contain_file('/etc/systemd/system/myservice.socket')
+            .with_ensure('absent')
+            .without_content
+            .that_requires('Service[myservice.socket]')
+        end
+        it 'sets up the socket service' do
+          is_expected.to contain_service('myservice.socket')
+            .with_ensure(false)
+            .with_enable(false)
+        end
+        it 'sets up the service unit file' do
+          is_expected.to contain_file('/etc/systemd/system/myservice.service')
+            .with_ensure('absent')
+            .without_content
+            .that_requires('Service[myservice.service]')
+        end
+        it 'sets up the service service' do
+          is_expected.to contain_service('myservice.service')
+            .with_ensure(false)
+            .with_enable(false)
+        end
+      end
+    end
+  end
+end