Release phase

[kingdonb]

Note the release command—this is run by Heroku just before a new release of the app is deployed, and we’ll use it to make sure our database is migrated.

ref: https://blog.heroku.com/a-rock-solid-modern-web-stack

https://devcenter.heroku.com/articles/release-phase

Is this supported in Builder?

(I think the answer is no, not yet... introduced on Heroku in Jun 2017)

[kingdonb]

I think the reference to the canonical answer for this has been reduced to:

apps:run run a command in an ephemeral app container

The original was a bit more expressive – http://docs.deis.io/en/latest/using_deis/manage-application/#administer-the-application

Deis applications use one-off processes for admin tasks like database migrations and other commands that must run against the live application.

actually, here it is:

https://deis.com/docs/workflow/applications/managing-app-lifecycle/#run-one-off-administration-tasks