Changes to Container Registry deployment behavior on 5/29

Change effective on 15 May 2018

On Tuesday 5/29, we will be making changes to Container Registry (Docker deploys) deployment behavior.

Today, when you run heroku container:push, your Docker images are built locally and then released to your app.

In the future, heroku container:push will no longer release your images. Instead, heroku container:push will build your images locally and push them to Container Registry, but it will not release them for deployment to your app.

To create a new release, using the images pushed to Container Registry, run heroku container:release.

We are changing this behavior to allow you to:

  1. Push several images and then release them all at the same time
  2. Use the release phase feature (run tasks before a new release of your app is deployed)
  3. Push one image, and release it to multiple process types with different CMDs, via heroku.yml or API

If you would like to try this new behavior before 5/29, you can run heroku labs:enable no-docker-releases --app $app_name.