Environment variables are nil in Rails app (can't connect to Google Drive)

Working with the book Learn Ruby on Rails, I'm stuck on the section of the tutorial where you connect to Google Drive to save the form submission to a spreadsheet. I'm not able to authenticate w/ Google because `Rails.application.secrets.email_provider_username` and `Rails.application.secrets.email_provider_password` are nil. More specifically, it seems like my rails app isn't seeing any of my environment variables. I've verified that the variables are set properly: ``` ynkwinl-ujurvt0:learn-rails katie$ printenv | grep GMAIL_USERNAME GMAIL_USERNAME=kjXXXXXX@gmail.com ``` And from the console: ``` learn-rails :001 > ENV["GMAIL_USERNAME"] => "kjXXXXXX@gmail.com" ``` But trying to access it via Rails: ``` learn-rails :001 > Rails.application.secrets.email_provider_username => nil ``` The relevant line of secrets.yml: ``` email_provider_username: <%= ENV["GMAIL_USERNAME"] %> ``` I've been stuck on this for an hour and can't find an answer (the previous question on this topic covered a slightly different scenario). I've worked around it by hard coding my username/password into the `secrets.yml` file, but I'd like to understand what's going on for future reference. Full 'secrets.yml' file for reference: ``` development: email_provider_username: <%= ENV["GMAIL_USERNAME"] %> email_provider_password: <%= ENV["GMAIL_PASSWORD"] %> domain_name: example.com mailchimp_api_key: <%= ENV["MAILCHIMP_API_KEY"] %> mailchimp_list_id: <%= ENV["MAILCHIMP_LIST_ID"] %> owner_email: <%= ENV["OWNER_EMAIL"] %> secret_key_base: very_long_random_string test: secret_key_base: very_long_random_string # Do not keep production secrets in the repository, # instead read values from the environment. production: email_provider_username: <%= ENV["GMAIL_USERNAME"] %> email_provider_password: <%= ENV["GMAIL_PASSWORD"] %> domain_name: <%= ENV["DOMAIN_NAME"] %> mailchimp_api_key: <%= ENV["MAILCHIMP_API_KEY"] %> mailchimp_list_id: <%= ENV["MAILCHIMP_LIST_ID"] %> owner_email: <%= ENV["OWNER_EMAIL"] %> secret_key_base: <%= ENV["SECRET_KEY_BASE"] %> ```