feat: add droneci runner

- ensure /data and docker are available
- add droneci runner configuration

modules/droneci/manifests/runner.pp

@@ -0,0 +1,24 @@
+class droneci::runner (
+  Hash $env_vars = {},
+  String $docker_image = 'drone/drone-runner-docker:1',
+  Array[String] $ports = [],
+  Array[String] $volumes = [],
+  Stdlib::Absolutepath $env_file = '/etc/sysconfig/droneci_runner',
+) {
+
+  # Create the environment file from a template
+  file { $env_file:
+    ensure  => file,
+    content => template('droneci/droneci_env.erb'),
+    mode    => '0644',
+  }
+
+  # Define the systemd service for Drone CI runner
+  systemd::unit_file { 'droneci-runner.service':
+    ensure    => present,
+    content   => template('droneci/droneci_runner_service.erb'),
+    enable    => true,
+    active    => true,
+    subscribe => File[$env_file],
+  }
+}