cf-blue-green

Cloud Foundry blue-green deployment

Allows zero-downtime deployments of applications within Cloud Foundry, with no additional setup needed.

Usage

1. Install the cf CLI, v6.12.0 or v6.12.1.
   • See Notes below for more info about the version restriction.
2. Run npm install -g cf-blue-green.
   • See Notes below for non-Node installation.
3. Run cf-blue-green <appname> (instead of cf-push) from your application directory to deploy.

This creates a copy of your already-running application, and safely switches traffic over to it. It's recommended that you try this script on a non-production application environment first, just to ensure that everything is switched over properly.

Notes

CF CLI

The reasons for the tight version restriction on the CF CLI is:

• < 6.12.0 doesn't respect the buildpack parameter.
• 6.12.2+ has an unresolved bug (as of this writing) that breaks cf-blue-green

To downgrade to 6.12.1 on Mac, if you use Homebrew:

brew uninstall cloudfoundry-cli
brew install https://raw.githubusercontent.com/pivotal/homebrew-tap/b39786b30125187bfa37a71eebef88222aa2c435/cloudfoundry-cli.rb

Manual installation

The script is distributed via NPM, but doesn't actually require Node.js beyond that. If you don't want to install Node, simply:

1. Download the script.
2. Run chmod a+x cf-blue-green.
3. Move the file somewhere in your PATH.

Using with Travis

Travis supports continuous deployment, which will automatically deploy your application after its tests pass on a specified branch. To use cf-blue-green with Travis, you need to use a script provider instead of the default Cloud Foundry provider. Your Cloud Foundry settings are read from environment variables.

Set up continuous deployment with the following settings in your .travis.yml file:

sudo: true
env:
  global:
  - CF_APP=[app name]
  - CF_API=[API endpoint]
  - CF_USERNAME=[user]
  - CF_ORGANIZATION=[organization]
  - CF_SPACE=[space]
  - secure: [CF_PASSWORD=[encrypted with Travis](http://docs.travis-ci.com/user/environment-variables/#Encrypted-Variables)]
before_deploy: npm install -g cf-blue-green
deploy:
  provider: script
  script: cf-blue-green-travis
  on:
    branch: [git branch you want to deploy]

Manifests

cf-blue-green creates a temporary manifest from your live application, meaning that it ignores the manifest.yml in your directory, if you have one. To deploy any changes to your manifest, use cf push directly.

Resources

More information about blue-green deployment, all of which this script drew from.

• http://www.cloudfoundry.rocks/blue-green-deployment-with-cloudfoundry/
• http://martinfowler.com/bliki/BlueGreenDeployment.html
• http://docs.pivotal.io/pivotalcf/devguide/deploy-apps/blue-green.html
• https://github.com/dlapiduz/step-cloud-foundry-deploy/blob/master/run.sh