Heroku: Display Git Revision Hash and Timestamp in Views?

Question

Let's say I have a Rails application deployed on Heroku. How can I display these pieces of information in my views?

• The Git hash for the last revision
• The Timestamp for the last revision

Answer 1

Heroku sets an environment variable with the commit hash ENV['COMMIT_HASH'].

As for the timestamp, you could hit the github api with the hash if you host your code there. Looks like the ruby-github gem can help you with this, or you could do it yourself with HTTParty.

Answer 2

The reason for this is because when your app is deployed onto the dyno grid to serve requests, it's compiled into a "slug" for fast deployment, and this slug doesn't have the git repo with it anymore.