Heroku-22 and no system Ruby

[edmorley]

Hi!

The Heroku-22 stack was just released:
https://devcenter.heroku.com/changelog-items/2429

In Heroku-22, there is no longer a system install of Ruby:
https://devcenter.heroku.com/articles/heroku-22-stack#system-ruby-is-no-longer-installed

This buildpack is written entirely in Ruby, and so in order for this buildpack to work on Heroku-22, one of the following will be necessary:

1. Have the buildpack vendor Ruby for use by this script (for an example of a buildpack doing this, see Vendor Ruby if an installation is not found heroku/heroku-buildpack-nginx#103).
2. Convert the buildpack to use shell/bash scripts instead.
3. Have users of this buildpack add the heroku/ruby buildpack prior to this one (they will also need to add a minimal Gemfile to their app source, if not already present, so the Ruby buildpack passes detection). However if mysql is needed before a Ruby MySQL gem is installed, this option might not be viable for this buildpack.
4. Use the APT buildpack to instead install mysql CLI from Ubuntu's APT repo (or else a PPA repo), and sunset this buildpack.

[stebogit]

Hey @edmorley would you mind suggesting a "minimal Gemfile" that would just work with the heroku/ruby buildpack? I'd like to try your suggested option 3, but I have no knowledge of ruby whatsoever and our app is PHP based, so I'm lost here.

[edmorley]

Hi! An empty Gemfile might work - I'm not the Ruby buildpack maintainer, so I don't know for sure and would have to experiment.

However I would strongly recommend one of the other options here.

Looking at this buildpack again now, I see it's using mysql 5.5 which is quite out of date.

As such, I would recommend option (4) over the others - particularly given that mysql libs are already installed in the stack images from APT - so installing the CLI from there too is more consistent.

See:
https://github.com/heroku/heroku-buildpack-apt

I believe the package you'll need is mysql-client:
https://packages.ubuntu.com/jammy-updates/mysql-client

[stebogit]

Thanks but I do need the old MyQSL version.

After some trial and error I figure out both a Gemfile AND a Gemfile.lock files are required.
The following ones seem to be working:

# Gemfile
source 'https://rubygems.org'

# Gemfile.lock
GEM
  remote: https://rubygems.org/
  specs:

PLATFORMS
  ruby

DEPENDENCIES

BUNDLED WITH
   1.17.3