Supports *experimental* ey.yml option sync_assets

When set to true, asset compilation will be executed on the primary
deployment server and rsync'd to other servers.

This feature is experimental.

It has been tested live but the current approach may not prove to be the
most effective way to speed up asset compilation. Future versions will
attempt to maintain a similar feature, but the implementation is subject
to change.

ChangeLog.md

@@ -3,9 +3,11 @@
 ## NEXT
 
   * Supports `config.ref` in deploy hooks. Synonymous with `config.branch` but more correct because the `input_ref` is automatically resolved to a SHA before deploy.
-  * Add new ey.yml option `precompile_assets_command`
+  * Supports new ey.yml option `precompile_assets_command`
     Setting `precompile_assets_command` overrides the asset precompile rake command. (default: `rake assets:precompile RAILS_GROUPS=assets`)
     Bundler binstubs are in PATH so gem binaries will load through bundler.
+  * Supports new ey.yml option `experimental_sync_assets`
+    Setting to `true` will cause assets to be compiled once and rsync'd to other servers.
 
 ## v2.5.0 (2014-09-23)
 

lib/engineyard-serverside/configuration.rb

@@ -102,8 +102,6 @@ def fetch_deprecated(attr, replacement, default)
       def_option :services_check_command, "which /usr/local/ey_resin/ruby/bin/ey-services-setup >/dev/null 2>&1"
       def_option(:services_setup_command) { "/usr/local/ey_resin/ruby/bin/ey-services-setup #{app}" }
 
-      def_option :restart_groups,         1
-
       DEFAULT_KEEP_RELEASES = 3
 
       def_option :keep_releases,          DEFAULT_KEEP_RELEASES
@@ -119,6 +117,10 @@ def fetch_deprecated(attr, replacement, default)
       def_boolean_option :maintenance_on_migrate,          true
       def_boolean_option(:maintenance_on_restart)          { required_downtime_stack? }
 
+      # experimental, need feedback from people using it, feature implementation subject to change or removal
+      def_option :restart_groups, 1
+      def_boolean_option :experimental_sync_assets, false
+
       alias app_name app
       alias environment framework_env # legacy because it would be nice to have less confusion around "environment"
       alias migration_command migrate

lib/engineyard-serverside/deploy.rb

@@ -34,7 +34,7 @@ def cached_deploy
           setup_services
           symlink_configs
           setup_sqlite3_if_necessary
-          run_with_callbacks(:compile_assets) # defined in RailsAssetSupport
+          run_with_callbacks(:compile_assets)
           enable_maintenance_page
           run_with_callbacks(:migrate)
           callback(:before_symlink)

lib/engineyard-serverside/rails_assets.rb

@@ -54,7 +54,19 @@ def run_precompile_assets_task
         asset_strategy.prepare do
           cd   = "cd #{paths.active_release}"
           task = "PATH=#{paths.binstubs}:$PATH #{framework_envs} #{precompile_assets_command}"
-          runner.run "#{cd} && #{task}"
+
+          # This is a hack right now, but I haven't iterated over it enough for a good solution yet.
+          if config.experimental_sync_assets?
+            shell.status "Compiling assets once on localhost (experimental_sync_assets: true)"
+            shell.logged_system("sh -l -c '#{cd} && #{task}'")
+
+            shell.status "Syncing assets to other remote servers (experimental_sync_assets: true)"
+            runner.servers.remote.run_for_each do |server|
+              server.sync_directory_command(paths.public_assets)
+            end
+          else
+            runner.run "#{cd} && #{task}"
+          end
         end
       end