Add NPM mirror hosting to unified mirrors

This patch makes the necessary modifications to host npm packages
on our mirrors. Changes include:

- index.json as a DirectoryIndex
- Rewrite rules for the AFS folder structure
- mod_substitute invocation to correctly reference absolute tarball
  url's described in the index.json files.

Change-Id: I1a5d560068e37e20ec565b8d864f89732ff5ad74

modules/openstack_project/manifests/mirror.pp

@@ -7,6 +7,7 @@ class openstack_project::mirror (
   $mirror_root = '/afs/openstack.org/mirror'
   $pypi_root = "${mirror_root}/pypi"
   $wheel_root = "${mirror_root}/wheel"
+  $npm_root = "${mirror_root}/npm"
 
   $www_base = '/var/www'
   $www_root = "${www_base}/mirror"
@@ -61,6 +62,16 @@ class openstack_project::mirror (
     ]
   }
 
+  file { "${www_root}/npm":
+    ensure  => link,
+    target  => "${npm_root}",
+    owner   => root,
+    group   => root,
+    require => [
+      File["${www_root}"],
+    ]
+  }
+
   file { "${www_root}/robots.txt":
     ensure   => present,
     owner    => 'root',
@@ -80,6 +91,12 @@ class openstack_project::mirror (
     }
   }
 
+  if ! defined(Httpd::Mod['substitute']) {
+    httpd::mod { 'substitute':
+      ensure => present,
+    }
+  }
+
   ::httpd::vhost { $vhost_name:
     port     => 80,
     priority => '50',

modules/openstack_project/templates/mirror.vhost.erb

@@ -42,6 +42,22 @@ NameVirtualHost <%= @vhost_name %>:<%= @port %>
     RewriteCond %{DOCUMENT_ROOT}/wheel/$1/$2/$2$3 -d
     RewriteRule ^/wheel/([^/]+)/([^/])([^/]*)(/.*)?$ /wheel/$1/$2/$2$3$4 [L]
 
+    <Directory <%= @docroot %>/npm/>
+      DirectoryIndex index.json
+
+      # npm's URL's are:
+      # /npm/-/index.json
+      # /npm/a/aabc/index.json
+      # /npm/a/aabc/latest/index.json
+      # /npm/a/aabc/-/aabc-0.0.0.tgz
+      RewriteCond %{REQUEST_URI} ^/npm/([^/])([^/]*)
+      RewriteCond %{DOCUMENT_ROOT}/npm/$1/$1$2 -d
+      RewriteRule ^([^/])([^/]*)(/.*)?$ $1/$1$2$3 [L]
+
+      AddOutputFilterByType SUBSTITUTE application/json
+      Substitute "s|http://localhost|http://<%= @srvname %>/npm|ni"
+    </Directory>
+
     ErrorLog /var/log/<%= scope.lookupvar("httpd::params::apache_name") %>/<%= @name %>_error.log
     LogLevel warn
     CustomLog /var/log/<%= scope.lookupvar("httpd::params::apache_name") %>/<%= @name %>_access.log combined