nginx / Puppet configuration for staging.zulip.com

We create a new sites-available entry which is essentially a duplicate of
sites-available/humbug-staging with s/humbug/zulip, and add the associated
symlink directive in Puppet.

(imported from commit febcb585ce93c21c6849d96458cc2bd096b30538)

servers/puppet/modules/humbug/files/nginx/sites-available/zulip-staging

@@ -0,0 +1,20 @@
+server {
+    listen 80;
+    server_name staging.zulip.com;
+    return 301 https://$server_name$request_uri;
+}
+
+server {
+    listen 443;
+
+    ssl on;
+    ssl_certificate /etc/ssl/certs/staging.zulip.com.combined-chain.crt;
+    ssl_certificate_key /etc/ssl/private/staging_and_dev.humbughq.com.key;
+
+    server_name staging.zulip.com;
+
+    # Avoid clickjacking attacks
+    add_header X-Frame-Options DENY;
+
+    include /etc/nginx/humbug-include/app;
+}

servers/puppet/modules/humbug/manifests/staging_app_frontend.pp

@@ -13,5 +13,9 @@ class humbug::staging_app_frontend {
     ensure => 'link',
     target => '/etc/nginx/sites-available/humbug-staging',
   }
+  file { '/etc/nginx/sites-enabled/zulip-staging':
+    ensure => 'link',
+    target => '/etc/nginx/sites-available/zulip-staging',
+  }
 
 }