Hidden Features of the Heroku CLI

Heroku’s CLI interface, the Heroku Toolbelt, has a lot of features which aren’t obvious, or are hidden away. Here are some of the useful ones I’ve found.

heroku run

Most people who use Heroku for Rails know about heroku run. For Rails apps, it’s used to run rake all the time. But did you know you can run bash and explore your app?

$ heroku run bash
Running `bash` attached to terminal... up, run.1563
$ ls -1
$ rm Gemfile # you can even delete files

I’ve used heroku run bash to debug filesystem problems and detect files that should be on Heroku, but were somehow missing in the compiled slug.

heroku open

heroku open is simple: it will open your Heroku site in your web browser. If you have a staging Heroku remote, you could do heroku open --remote staging. Or you can use the --app option and do heroku open --app sushi.

heroku ps

Are your processes running smoothly after that last deploy? Check with heroku ps:

$ watch heroku ps
Every 2.0s: heroku ps -r staging          Tue Dec 24 10:46:07 2013

=== web (1X): `bundle exec unicorn -p $PORT -c ./config/unicorn.rb`
web.1: starting 2013/12/20 17:21:48

I’ll let that run for a minute to ensure nothing crashes after a deploy.

heroku git:remote

heroku git:remote can add a git remote to your app:

# Add a git remote named foobar that points to the app-staging application
heroku git:remote --app app-staging --remote foobar

This command would be a good addition to a bin/setup script.

heroku addons

I’m sure you’ve used heroku addons:add newrelic to add an addon, but how about these two?

heroku pg:psql

Sometimes I need to run SQL against a Heroku database. I could do heroku pg:psql to get a psql prompt and type in my SQL, but what if I need to run the same command a few times in a row? Then I use shell here strings, like this:

heroku run pg:psql <<<"SELECT COUNT(*) FROM users WHERE email = 'gabebw@gabebw.com'"

This prints out the results immediately, and I can re-run it easily since the whole command is in my shell history.

Any suggestions?

Any suggestions? I’m available on Twitter: @gabebw.