Running Rake Commands
Last updated March 24, 2023
Table of Contents
Rake tasks are executed as one-off dynos on Heroku, using the same environment as your app’s dynos. You can run Rake tasks within the remote app environment using the heroku run rake command as follows:
$ heroku run rake db:version
Running `rake db:version` attached to terminal... up, run.1
(in /home/slugs/41913_06f36ef_ab3a/mnt)
Current version: 20231118092504
You can pass Rake arguments, run multiple tasks, and pass environment variables just as you would locally. For instance, to migrate the database to a specific version with verbose backtraces:
$ heroku run rake --trace db:migrate VERSION=20231118092504
After running a migration, you’ll want to restart your app with heroku restart to reload the schema and pick up any schema changes.
Limitations
Not all Rake features are supported on Heroku. The following is a list of known limitations:
Rake tasks that write to disk, such as
rake db:schema:dump, aren’t compatible with Heroku’s ephemeral filesystem.The
db:resettask isn’t supported. Heroku apps don’t have permission to drop and create databases. Use theheroku pg:resetcommand instead.
Heroku run bash
You can access the rake command interactively through the heroku run bash command. This command spins up a one-off dyno and give you shell access where you can run rake commands:
$ heroku run bash
Running bash on ⬢ polar-inlet-4930... up, run.2581 (Standard-1X)
~$ rake db:migrate --trace
** Invoke db:migrate (first_time)
** Invoke db:load_config (first_time)
** Invoke environment (first_time)
** Execute environment
...