Add zipassets.sh to facilitate gzip_static use (#537)

.gitignore

@@ -7,3 +7,4 @@ controllers/config.go*
 testing/
 *.orig
 debug
+public/**/*.gz

README.md

@@ -182,7 +182,8 @@ MySQL> CREATE DATABASE stakepool;
 ### Nginx/web server
 
 - Adapt sample-nginx.conf or setup a different web server in a proxy
-  configuration.
+  configuration. To prepare pre-zipped files to save the reverse proxy the
+  trouble of compressing data on-the-fly, see the zipassets.sh script.
 
 ### stakepoold setup
 

sample-nginx.conf

@@ -55,6 +55,8 @@ http {
 
         # Serve static resources directly.
         location /assets/* {
+                # See the zipassets.sh script, which can be used to prepare the
+                # pre-zipped files used by gzip_static.
                 gzip_static on; # use .gz files for pre-compressed data
                 root /opt/dcrstakepool/public;
                 # Set the Cache-Control and Expires headers for the static assets.

zipassets.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+#
+# This script helps prepare pre-zipped static assets for use with reverse proxy
+# features like nginx's gzip_static.
+
+echo "Gzipping assets for use with gzip_static..."
+find ./public -type f -name "*.gz" -execdir rm {} \;
+# Use GNU parallel if it is installed.
+if [ -x "$(command -v parallel)" ]; then
+    if [ -x "$(command -v 7za)" ]; then
+        find ./public -type f -not -name "*.gz" | parallel --will-cite --bar 7za a -tgzip -mx=9 -mpass=13 {}.gz {} > /dev/null
+    else
+        find ./public -type f -not -name "*.gz" | parallel --will-cite --bar gzip -k9f {} > /dev/null
+    fi
+elif [ -x "$(command -v 7za)" ]; then
+    find ./public -type f -not -name "*.gz" -execdir 7za a -tgzip -mx=9 -mpass=13 {}.gz {} \; > /dev/null    
+else
+    find ./public -type f -not -name "*.gz" -execdir gzip -k9f {} \; > /dev/null
+fi
+
+# Clean up incompressible files.
+find ./public -type f -name "*.png.gz" -execdir rm {} \;
+find ./public -type f -name "*.eot.gz" -execdir rm {} \;
+find ./public -type f -name "*.gz.gz" -execdir rm {} \;
+find ./public -type f -name "*.woff*.gz" -execdir rm {} \;