canonicalize libraries: script to convert from Apache format to Nginx

Merge of Vid's #533 with some fixes.

README.md

@@ -101,6 +101,28 @@ X-Page-Speed: 1.6.29.5-...
 Looking at the source of a few pages you should see various changes, such as
 urls being replaced with new ones like `yellow.css.pagespeed.ce.lzJ8VcVi1l.css`.
 
+### Use Google Hosted JS (Canonicalize Javascript Libraries)
+
+This is handy when you want to allow some of the more common javascript files to
+load from Google's servers.  See [the
+documentation](https://developers.google.com/speed/pagespeed/module/filter-canonicalize-js).
+
+To make this work with ngx_pagespeed, run:
+
+```bash
+$ scripts/pagespeed_libraries_generator.sh > ~/pagespeed_libraries.conf
+$ sudo mv ~/pagespeed_libraries.conf /etc/nginx/
+```
+
+In the Nginx.conf file above, right after you say `pagespeed on`; add this
+
+```nginx
+include pagespeed_libraries.conf;
+pagespeed EnableFilters canonicalize_javascript_libraries;
+```
+
+Now most of your common JS files will load from `//ajax.googleapis.com/...``.
+
 For complete documentation, see [Using
 PageSpeed](https://developers.google.com/speed/pagespeed/module/using).
 

scripts/pagespeed_libraries_generator.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+#
+# Converts pagespeed_libraries.conf from Apache-format to Nginx-format,
+# supporting the canonicalize_javascript_libraries filter.
+# Inspired by https://github.com/pagespeed/ngx_pagespeed/issues/532
+#
+# Usage:
+#   scripts/pagespeed_libraries_generator.sh > pagespeed_libraries.conf
+#
+# Then have nginx include that configuration file and enable the filter
+# canonicalize_javascript_libraries.
+#
+# Author: vid@zippykid.com (Vid Luther)
+#         jefftk@google.com (Jeff Kaufman)
+
+URL="https://modpagespeed.googlecode.com/svn/trunk/src/"
+URL+="net/instaweb/genfiles/conf/pagespeed_libraries.conf"
+curl -s "$URL" \
+    | grep ModPagespeedLibrary \
+    | while read library size hash url ; do
+  echo "  pagespeed Library $size $hash $url;"
+done