Missing `secret_key_base` for 'production' environment on Ubuntu 18.04 server (Rails 6.0), multiple topics tried

Rails 5.2 and later uses encrypted credentials for storing sensitive app's information, which includes secret_key_base by default. These credentials are encrypted with the key stored in master.key file. Git repository, generated by default Rails application setup, includes credentials.yml.enc but ignores master.key. After the deployment, which usually involves git push, Rails production environment should be augmented with this key some way.

So you have two options. You can securely upload master.key to production host via scp or sftp. Or you can establish shell environment variable RAILS_MASTER_KEY within the context of a user that runs rails server process. The former option is preferred, but as you have dotenv-rails gem installed, you'd create .env.production file under app's root and put there a line

RAILS_MASTER_KEY="your_master-key_content"

Don't forget to ensure that gem dotenv-rails isn't restricted within Gemfile by development and test Rails environments.

By the way since passenger module ver. 5.0.0 you can set shell environment variables right from nginx.conf

run rake secret in your local machine and this will generate a key for you

make config/secrets.yml file

add the generated secret key here

production: secret_key_base: asdja1234sdbjah1234sdbjhasdbj1234ahds…

and redeploy the application after commiting

i had the same issue and resolved by this method.

It would be more secure to generate your key on the server and use it there, rather than push it to your repo from a local machine.

Instead of ~/.bashrc do this for using environment variables;

1. As root user, navigate to the # directory (can probably just use cd ..)
2. Enter nano home/<yourAppUser>/.bash_profile to navigate to (and create) the file to store the ENV
3. As you have already, just write this in the file: export SECRET_KEY_BASE="GENERATED_KEY_1"

You can store your database password here as well.