Reduce Deployment Risk with Blue-Green Deployments

This page shows you how to deploy a new version of your App and migrate traffic over from an old to a new version.

Pushing the initial App

Use the Kf CLI to push the initial version of your App with any Routes:

$ kf push app-v1 --route my-app.my-space.example.com

Pushing the updated App

Use the Kf CLI to push a new version of your App without any Routes:

$ kf push app-v2 --no-route

Adding Routes to the updated App

Use the Kf CLI to bind all existing Routes to the updated App with a weight of 0 to ensure they don't get any requests.

$ kf map-route app-v2 my-space.example.com --hostname my-app --weight 0

Shifting traffic

Start shifting traffic from the old App to the updated App by updating the weights on the Routes.

$ kf map-route app-v1 my-space.example.com --hostname my-app --weight 80
$ kf map-route app-v2 my-space.example.com --hostname my-app --weight 20

If the deployment is going well, you can shift more traffic by updating the weights again:

$ kf map-route app-v1 my-space.example.com --hostname my-app --weight 50
$ kf map-route app-v2 my-space.example.com --hostname my-app --weight 50

Note: Weights split traffic proportionally to the sum of the weights of all Apps mapped to the Route. It's common practice to treat weights as percentages.

Completing traffic shifting

Once you're satisfied that the new service hasn't introduced regressions, complete the rollout by shifting all traffic to the new instance:

$ kf map-route app-v1 my-space.example.com --hostname my-app --weight 0
$ kf map-route app-v2 my-space.example.com --hostname my-app --weight 100

Turning down the original App

Once you're satisfied that quick rollbacks aren't needed, remove the original route and stop the App:

$ kf unmap-route app-v1 myspace.example.com --hostname my-app
$ kf stop app-v1

Or delete the App and all associated Route mappings:

$ kf delete app-v1