feat: add an easy maintenance page support

manifests/resource/vhost.pp

@@ -231,6 +231,7 @@ define nginx::resource::vhost (
   $owner                        = $::nginx::config::global_owner,
   $group                        = $::nginx::config::global_group,
   $mode                         = $::nginx::config::global_mode,
+  $maintenance                  = false,
 ) {
 
   validate_re($ensure, '^(present|absent)$',

templates/vhost/vhost_header.erb

@@ -102,6 +102,14 @@ server {
   add_header              <%= key %> <%= @add_header[key] %>;
   <%- end -%>
 <% end -%>
+<% if @maintenance -%>
+  set $maintenance "on";
+<% else -%>
+  set $maintenance "off";
+<% end -%>
+  if ($maintenance = "on") {
+      return 503;
+  }
 <% if @rewrite_to_https -%>
   if ($ssl_protocol = "") {
        return 301 https://$host<% if @ssl_port.to_i != 443 %>:<%= @ssl_port %><% end %>$request_uri;

templates/vhost/vhost_ssl_header.erb

@@ -72,6 +72,14 @@ server {
   <%- end -%>
 
 <% end -%>
+<% if @maintenance -%>
+  set $maintenance "on";
+<% else -%>
+  set $maintenance "off";
+<% end -%>
+  if ($maintenance = "on") {
+      return 503;
+  }
 <% if Array(@resolver).count > 0 -%>
   resolver                  <% Array(@resolver).each do |r| %> <%= r %><% end %>;
 <% end -%>