env_variables cannot be used in deployment

[nek023]

Hi,

This is a issue about ruby25_app_builder rather than this gem.
Sorry if it isn't the right place to ask.

I found that environment variables defined in app.yaml cannot be used in gcloud app deploy.

For example, my Rails app initializes an API client on launch.
So I wrote an initializer that reads API key from environment variable:

config/initializers/sample_initializer.rb

api_key = ENV['SAMPLE_API_KEY']
raise 'sample_api_key is required' if api_key.blank?

SampleClient.config.api_key = api_key

Then I deploy this app with gcloud app deploy.
During deploy, ruby25_app_builder automatically runs rails assets:precompile if public/assets does not exists.
But this command fails due to missing env var.

Logs from Cloud Build:

Step #1 - "builder": [2019-12-15 09:59:24 INFO] => Checking for Rails sprockets
Step #1 - "builder": [2019-12-15 09:59:24 INFO] => Running Rails asset precompilation
Step #1 - "builder": [2019-12-15 09:59:24 INFO] ["bundle", "exec", "bin/rails", "assets:precompile"]
Step #1 - "builder": rails aborted!
Step #1 - "builder": sample_api_key is required

This can be avoided by running RAILS_ENV=production rails assets:precompile in advance.
But I think this should be done by ruby25_app_builder.
Are there any plans to fix this?