Add version tag

app/assets/stylesheets/app.css.scss

@@ -16,3 +16,9 @@
   display:block;
   font-size:10px;
 }
+
+.footer {
+  color: #777;
+  padding-top: 15px;
+  font-size: 10px;
+}

app/views/layouts/application.haml

@@ -62,3 +62,6 @@
         .alert{class: type}= flash[:notice] || flash[:alert]
       = yield
 
+      .footer.text-right
+        Version
+        = CURRENT_COMMIT_HASH

config/deploy.rb

@@ -38,6 +38,7 @@ end
 set :shared_paths, [
   'config/application.yml',
   'config/database.yml',
+  'config/initializers/current_commit_hash.rb',
   'log',
   'public/system',
   'export/zonefiles'
@@ -93,6 +94,7 @@ task deploy: :environment do
     # Put things that will set up an empty directory into a fully set-up
     # instance of your project.
     invoke :'git:clone'
+    invoke :load_commit_hash
     invoke :'deploy:link_shared_paths'
     invoke :'bundle:install'
     invoke :'rails:db_migrate'
@@ -118,6 +120,14 @@ task rollback: :environment do
   end
 end
 
+desc 'Loads current commit hash'
+task load_commit_hash: :environment do
+  queue! %(
+    echo "CURRENT_COMMIT_HASH = '$(git --git-dir #{deploy_to}/scm rev-parse --short HEAD)'" > \
+    #{deploy_to}/shared/config/initializers/current_commit_hash.rb
+  )
+end
+
 desc 'Restart Passenger application'
 task restart: :environment do
   queue "mkdir -p #{deploy_to}/current/tmp; touch #{deploy_to}/current/tmp/restart.txt"

config/initializers/current_commit_hash.rb

@@ -0,0 +1 @@
+CURRENT_COMMIT_HASH = `git rev-parse --short HEAD`