Git Deployment Workflow and a Capistrano Recipe

After experimenting with several workflows for deployment in git, I've finally found one I really like.

• You can push to staging at any time; every staging push is automatically tagged with a unique tag.
• You can only push an existing staging tag to production. This helps to enforce QA of all pushes to production.

Using tags instead of branches has a lot of benefits:

• No permanent remote branches on "canonical" git repo
• More transparent historical record of what's been pushed where & when, and easily seeing what's changed between deploys
• Uses tags for what they're meant for instead of "hacking" branches to do a job they weren't meant to do

One of the coolest things that fell out of this new workflow is the ability to see a changelog between two points:

$ git log --format=oneline production-2009-09-09.6..production-2009-09-17.11

5c0b4c9a3f45471926d8372d6dd3606b107ea3d3 Fix rake externals task to properly update phocoa cache. fix copy/paste naming bug.

62a943e96e90935c491f589efdc926c6975f7fb6 Merge branch 'master' of github.com:apinstein/neybor

9a5bd41d9ab9947b134db72bba2a226ed36107f8 [Story1111494] Make 0-priced syndicators show up as free.

8248fb1eecfc2c59007a99ab499bf6d86942d055 [Story1301780] Added a link to the dashboard on the main admin page

e2af47e70b3ba75fdd9c253f349ef35b7c61c01f Added site-wide stats and changed colors on all graphs

66b37218a4342f2e4ef6b16bd120f6e350284fea Merge branch 'master' into fixing_tests

The concepts used in this workflow can be used with any deployment engine, however we use Capistrano and have published our git+capistrano deployment recipe that allows you to easily implement this workflow in any git+capistrano project.

Requires the cap multistage extension:

gem install capistrano capistrano-ext

INSTALLATION: require the gitflow file after your multistage require

require 'capistrano/ext/multistage'

require 'git-deployment/gitflow.rb'

Expects stages "staging" and "production".

USE:

PUSH TO STAGING:

Whenever you want to push the currently checked-out code to staging, just do:

cap staging deploy

gitflow will automatically:

- create a unique tag in the format of 'staging-YYYY-MM-DD.X'

- configure multistage to use that tag for the deploy

- push the code and tags to the remote "origin"

- and run the normal deploy task for the staging stage.

PUSH TO PRODUCTION:

Whenever you want to push code to production, you must specify the staging tag you wish to promote to production:

cap production deploy -s tag=staging-2009-09-08.2

gitflow will automatically:

- alias the staging tag to a production tag like: production-2008-09-08.2

- configure multistage to use that tag for the deploy

- push the code and tags to the remote "origin"

- and run the normal deploy task for the production stage.

Influences and References:

• http://reinh.com/blog/2009/03/02/a-git-workflow-for-agile-teams.html - good concepts, but not automated or totally tag-based
• http://www.brynary.com/2008/8/3/our-git-deployment-workflow - Influential, but uses branches instead of tags