Problems deploying Phoenix to Heroku

I tried to deploy a sample Phoenix application to Heroku so I read some blogposts about it etc. Didn’t get it to work.

There were essentialiy two probelms.

• Migrations.
• Assets.

Preconditions

• Elixir 1.0.4
• Erlang 17.5
• Phoenix 0.11.0
• Ecto 0.10.0
• HashNuke heroku-buildpack-elixit (17 April 2015)

Migrations

heroku run ecto migrate --no-create

You need the --no-create, otherwise mix complains that the db could not be created. The error message is sort of disguised.

** (Mix) The database for repo Cronos.Repo couldn't be created, reason given: Error: You must install at least one postgresql-client-<version> package.

Assets

I deployed my app, and it was just plain HTML. No css. Instead i got 404 NOT FOUND for all assets.

Apperantly heroku builds and compiles the app, collects all dependencies but does not compile sass. So the repo you published to Heroku does not have any css at all. Turns out that /priv/static/css and priv/static/js are included in the standard .gitignore for Phoenix applications.

So as a quickfix we just have to unigore those files. Push the new commit and voila!

However, compiled css and js in the repo is not very nice is it. I asked around abit and googled some; no solution at the moment. If you find any, let me know.

Written by Simon Ström as a way to remember. It's a dev log of thinks I want to remember.