railties/lib/rails/generators/rails/credentials/templates/credentials.yml.tt
# aws:
# access_key_id: 123
# secret_access_key: 345
<% unless options.skip_secret_key_base? -%>
# Used as the base secret for all MessageVerifiers in Rails, including the one protecting cookies.
secret_key_base: <%= secret_key_base %>
<% end -%>