implement configfile validation (#18)

* implement configfile validation

* update Reference file

REFERENCE.md

@@ -47,6 +47,7 @@ The following parameters are available in the `otelcol` class:
 * [`package_name`](#-otelcol--package_name)
 * [`package_ensure`](#-otelcol--package_ensure)
 * [`service_name`](#-otelcol--service_name)
+* [`service_configcheck`](#-otelcol--service_configcheck)
 * [`environment_file`](#-otelcol--environment_file)
 * [`run_options`](#-otelcol--run_options)
 * [`config_file`](#-otelcol--config_file)
@@ -93,6 +94,14 @@ Name of the service used
 
 Default value: `$package_name`
 
+##### <a name="-otelcol--service_configcheck"></a>`service_configcheck`
+
+Data type: `Boolean`
+
+Check config before service reloads
+
+Default value: `true`
+
 ##### <a name="-otelcol--environment_file"></a>`environment_file`
 
 Data type: `String`

manifests/init.pp

@@ -6,6 +6,8 @@
 #   Ensure for the package
 # @param service_name
 #   Name of the service used
+# @param service_configcheck
+#   Check config before service reloads
 # @param environment_file
 #   path of the environment file used for service
 # @param run_options
@@ -52,6 +54,7 @@
   String  $package_name                          = 'otelcol',
   Enum['present','absent','installed','latest']  $package_ensure       = 'installed',
   String  $service_name                          = $package_name,
+  Boolean $service_configcheck                   = true,
   String  $environment_file                      = "/etc/${package_name}/${package_name}.conf",
   Optional[String]  $run_options                 = undef,
   String  $config_file                           = "/etc/${package_name}/config.yaml",

manifests/service.pp

@@ -14,20 +14,36 @@
 # @api private
 class otelcol::service (
   Stdlib::Ensure::Service $ensure            = $otelcol::service_ensure,
+  String  $config_check_command              = "${otelcol::service_name} validate --config=${otelcol::config_file}",
+  Boolean $config_check                      = $otelcol::service_configcheck,
 ) {
   # include install
   include otelcol::install
 
-  # systemd::dropin_file { 'otelcol_service':
-  #   unit     => 'otelcol.service',
-  #   content  => epp('otelcol/otelcol.dropin.epp'),
-  #   filename => 'otelcol_override.conf',
-  # }
-  # ~>
+  if $config_check {
+    exec { 'otelcol_config_check':
+      command     => $config_check_command,
+      refreshonly => true,
+      path        => [
+        '/usr/local/sbin',
+        '/usr/local/bin',
+        '/usr/sbin',
+        '/usr/bin',
+        '/sbin',
+        '/bin',
+      ],
+    }
+  }
+
+  $service_require = $config_check ? {
+    true => [Exec['otelcol_config_check'], Package['otelcol']],
+    false => Package['otelcol'],
+  }
+
   service { 'otelcol':
     ensure    => $ensure,
     name      => $otelcol::service_name,
-    require   => Package['otelcol'],
+    require   => $service_require,
     subscribe => [Concat['otelcol-config'], File['otelcol-environment']],
   }
 }

spec/classes/otelcol_spec.rb

@@ -341,6 +341,17 @@
         it { is_expected.to contain_service('otelcol').with_ensure('stopped') }
       end
 
+      context 'with service_configcheck' do
+        let :params do
+          {
+            service_configcheck: true,
+          }
+        end
+
+        it { is_expected.to compile.with_all_deps }
+        it { is_expected.to contain_service('otelcol').that_requires('Exec[otelcol_config_check]') }
+      end
+
       context 'do not manage Service' do
         let :params do
           {