Ruby version mismatch

Questions / Help Build debugging
1

I’ve spent a couple hours trying to get my first deploy of an existing rails app (running on Heroku) to deploy on Fly.io, but seem to keep getting stuck:

My cmd in the fly.toml is just

cmd = 'bin/rails server -p $PORT -e $RAILS_ENV'

(same as the Procfile for heroku)

but it just fails with:

Your Ruby version is 2.7.0, but your Gemfile specified 3.1.0
2

I switched buildpacks to use


[build]
  builder = "paketobuildpacks/builder:full"
  buildpacks = ["docker://gcr.io/paketo-buildpacks/mri:0.6.0", "gcr.io/paketo-buildpacks/ruby"]

and now ruby 3.1.0 and bundle install work, but the build process doesn’t have access to secrets or env vars now, so the builds fail:

Paketo Rails Assets Buildpack 0.4.1
  Executing build process
    Running 'bundle exec rails assets:precompile assets:clean'
failed to execute bundle exec output:
Calling `DidYouMean::SPELL_CHECKERS.merge!(error_name => spell_checker)' has been deprecated. Please call `DidYouMean.correct_error(error_name, spell_checker)' instead.
Calling `DidYouMean::SPELL_CHECKERS.merge!(error_name => spell_checker)' has been deprecated. Please call `DidYouMean.correct_error(error_name, spell_checker)' instead.
rails aborted!
KeyError: key not found: "MY_ENV_VAR"
3

I think my real issue is that the builder and buildpacks don’t have access to the env vars or secrets, so I’ll need to find a way to inject them into the [build.args section]


[build]
  builder = "paketobuildpacks/builder:full"
  buildpacks = ["docker://gcr.io/paketo-buildpacks/mri:0.6.0", "gcr.io/paketo-buildpacks/ruby"]
  [build.args]
    MY_ENV_VAR="1234567890"

[env]
  MY_ENV_VAR = "1234567890"
4

Finally got a build to deploy, just had to seed the build.args with copies of blank env vars (only used at runtime):

build]
  builder = "paketobuildpacks/builder:full"
  buildpacks = ["docker://gcr.io/paketo-buildpacks/mri:0.6.0", "gcr.io/paketo-buildpacks/ruby"]
  [build.args]
    DATABASE_URL="sqlite:///tmp/db.sqlite3"
    CRON_PROCESS=""
    RAILS_MASTER_KEY=""
    FIREBASE_API_KEY=""
    S3_BUCKET_NAME=""
    S3_REGION=""
    SECOND_DATABASE_URL=""
    SOME_API_KEY=""
    ANOTHER_API_KEY=""
    SENTRY_DSN=""
    THIRD_API_KEY=""
    SOME_OTHER_ENV=""
    HOSTNAME=""

[env]
    DATABASE_URL="postgres://user@host:5434/dbname?ssl_mode=verify"
    CRON_PROCESS="123456789"
    RAILS_MASTER_KEY="123456789"
    FIREBASE_API_KEY="123456789"
    S3_BUCKET_NAME="123456789"
    S3_REGION="123456789"
    SECOND_DATABASE_URL="123456789"
    SOME_API_KEY="123456789"
    ANOTHER_API_KEY="123456789"
    SENTRY_DSN="123456789"
    THIRD_API_KEY="123456789"
    SOME_OTHER_ENV="123456789"
    HOSTNAME="123456789"
5

I’m glad you got it working! Unfortunately that’s the best way to handle missing secrets during a build. We deliberately don’t leak secrets to flyctl because of the security risk, and you probably don’t want connections opening to your prod db anyway.

6

Thank you for not passing the secrets! My build command doesn’t and shouldn’t even rely on them. Just took me a second to figure things out. Thanks!

1 Like
7

It’s usually a library doing sanity checks when loaded as a byproduct of building assets. fwiw this conversation gave me an idea that might help make this less of an issue Inject placeholder secrets/envs into build vars · Issue #778 · superfly/flyctl · GitHub

1 Like
8

I’m seeing the exact same ruby mismatch error with the heroku/buildpacks:20 buildback!

My app is deployed and running just fine, but I need to run a one-off rake process (seeding the db with data), and so I ssh in with fly ssh console (which works), then I cd app, but I can’t run anything in the bin folder of my rails project! I’m getting these confusing errors:

# bin/rails console
Your Ruby version is 2.7.0, but your Gemfile specified 3.0.2
# bin/bundle exec rails console
bundler: command not found: rails
Install missing gem executables with `bundle install`
# bundle -v
/bin/sh: 6: bundle: not found

Maybe I am just new to Docker, but how is it that my app is running just fine and yet when I SSH in the container, bundler isn’t installed, nor rails, nor the proper version of ruby? Any links to resources where I can learn more about this aspect of Docker would also be appreciated.

Or even just tips on how to run a rake db:seed task as a one-off. Thank you!

1 Like
9

Same problem here, I haven’t found a way to run a rails console while ssh into the app.

10

@password @user98 I fixed it by checking the Dockerfile.

ARG RUBY_VERSION=X.X.X