Issue 4068 - Redirect tailing-dot hostname requests to use canonical domain name

modules/nginx/templates/site.erb

 <% include_file = lambda do |url| %>
   <% content = Puppet::FileServing::Content.indirection.find(url) %>
   <% if content %>
     <%= content.content %>
   <% else %>
     <% raise StandardError, "Failed to resolve source URL #{url}" %>
   <% end %>
 <% end %>
 
 <% server_name = lambda do |domain, alt_names| %><%= domain %><% @alt_names.each do |name| %>, <%= name %><% end %><% end %>
@@ skipping 18 matching lines @@
     location /
     {
       rewrite (.*) https://$host$1 permanent;
     }
   }
   server
   {
     server_name <% server_name[domain, alt_names] %>;
 
     <% if is_default %>
-      listen 443 ssl spdy default_server;
-      listen [::]:443 ssl spdy default_server;
+      listen 443 ssl http2 default_server;
+      listen [::]:443 ssl http2 default_server;
     <% else %>
-      listen 443 ssl spdy;
-      listen [::]:443 ssl spdy;
+      listen 443 ssl http2;
+      listen [::]:443 ssl http2;
     <% end %>
 
     ssl_certificate <%= certificate %>;
     ssl_certificate_key <%= private_key %>;
 
     add_header Strict-Transport-Security max-age=31536000;
 <% else %>
   server
   {
     server_name <% server_name[domain, alt_names] %>;
@@ skipping 10 matching lines @@
 access_log /var/log/nginx/<%= log %> <%= log_format %>;
 
 # redirect server error pages to the static page /50x.html
 #
 error_page 500 502 503 504 /50x.html;
 location = /50x.html
 {
   root /usr/share/nginx/html;
 }
 
-if ($http_host ~ "\.$") {

[Wladimir Palant, 2016/05/24 19:08:07]

Nit: The opening bracket belong on the next line.

-  rewrite ^(.*) $scheme://$host$1 permanent;

[Wladimir Palant, 2016/05/24 19:08:07]

This relies on undocumented behavior, namely $host being identical to $http_host
but with the trailing dot removed. At the very least you should link to
https://www.ruby-forum.com/topic/163942#719893 which seems to be your source for
this information (via Stack Overflow). A better option might be avoiding
undocumented behavior altogether:

  if ($http_host ~ "^(.*)\.$")
  {
    set $host_without_trailing_dot $1;
    rewrite ^(.*) $scheme://$host_without_trailing_dot$1 permanent;
  }

+if ($http_host ~ "^(.+)\.$")
+{
+  set $canonical_host $1;
+  rewrite ^(.*) $scheme://$canonical_host$1 permanent;
 }
 
 <% if @content %>
   <%= content %>
 <% end %>
 
 <% if @source %>
   <% include_file[source] %>
 <% end %>
 }