Create nginx_proxy role

Used to configure hosts entries in the Gitea and Drone VMs, as well as
the allowed webhooks config for Gitea.

roles/nginx_proxy.rb

@@ -0,0 +1,13 @@
+name "nginx_proxy"
+
+default_run_list = %w(
+  kosmos_discourse::nginx
+  kosmos_gitea::nginx
+  kosmos_drone::nginx
+)
+
+env_run_lists(
+  '_default' => default_run_list,
+  'development' => [],
+  'production' => default_run_list
+)