dotenv instead of Rails credentials

The deployment is done on a Dokku server. It sets the DATABASE_URL
automatically.

Gemfile.lock

@@ -124,9 +124,6 @@ GEM
       responders
       warden (~> 1.2.3)
     dotenv (3.1.7)
-    dotenv-rails (3.1.7)
-      dotenv (= 3.1.7)
-      railties (>= 6.1)
     down (5.4.2)
       addressable (~> 2.8)
     drb (2.2.1)
@@ -575,7 +572,7 @@ DEPENDENCIES
   cssbundling-rails
   debug
   devise
-  dotenv-rails
+  dotenv
   factory_bot_rails
   fastimage
   font-awesome-rails

config/credentials/development.yml.enc

@@ -1 +0,0 @@
-p4iCDmwxjQ5zC6i3QVNCnlW++oxVLD0AKnflI6lsRBQ1bLTcBA3+8EFI9itIiv7WUJYF+0xGz1bqNq8e9Kk+tEq7C1GVgbuS3xEjG2I0Kt1GbTjvl0aeCd7WHR5xWHlCIXmZVhO/OL4SNc876WYpQqwWRwHkPND0QGAmfWOgy2H14V6LVYh1d7fhPdSYBr4b6oPMMQW6fqAjQ8Oq5TVUznRiRLQfFhAYz2DklMAoASjhAWK39U76JWYqu8VCq08+3V/geXYtQfcsvQ1twq08RFcJbZsCG7slOI8fPW5Oq2dCpw==--mvh3V6FOm1I5+pal--y0AKTyuXuwhXl6iMcT29tw==

config/database.yml

@@ -9,7 +9,7 @@ production:
   primary:
     <<: *default
     # database: storage/production.sqlite3
-    url: <%= Rails.application.credentials.db.url %>
+    url: <%= ENV['DATABASE_URL'] %>
     pool: 10
   cache:
     <<: *default

config/environments/development.rb

@@ -1,4 +1,4 @@
-require "active_support/core_ext/integer/time"
+require 'active_support/core_ext/integer/time'
 
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
@@ -17,10 +17,10 @@ Rails.application.configure do
 
   # Enable/disable Action Controller caching. By default Action Controller caching is disabled.
   # Run rails dev:cache to toggle Action Controller caching.
-  if Rails.root.join("tmp/caching-dev.txt").exist?
+  if Rails.root.join('tmp/caching-dev.txt').exist?
     config.action_controller.perform_caching = true
     config.action_controller.enable_fragment_cache_logging = true
-    config.public_file_server.headers = { "cache-control" => "public, max-age=#{2.days.to_i}" }
+    config.public_file_server.headers = { 'cache-control' => "public, max-age=#{2.days.to_i}" }
   else
     config.action_controller.perform_caching = false
   end
@@ -34,12 +34,12 @@ Rails.application.configure do
   # Don't care if the mailer can't send.
   config.action_mailer.raise_delivery_errors = false
   config.action_mailer.smtp_settings = {
-    address:              'localhost',
+    address: 'localhost',
-    port:                 25,
+    port: 25,
     enable_starttls_auto: false
   }
   config.action_mailer.default_url_options = {
-    host: "screenshots.debian.net",
+    host: 'screenshots.debian.net',
     protocol: 'https'
   }
 
@@ -47,7 +47,7 @@ Rails.application.configure do
   config.action_mailer.perform_caching = false
 
   # Set localhost to be used by links generated in mailer templates.
-  config.action_mailer.default_url_options = { host: "localhost", port: 3000 }
+  config.action_mailer.default_url_options = { host: 'localhost', port: 3000 }
 
   # Print deprecation notices to the Rails logger.
   config.active_support.deprecation = :log
@@ -77,8 +77,8 @@ Rails.application.configure do
   config.package_sources = [
     {
       description: 'Debian Unstable (Sid)', type: 'apt', url: 'http://ftp.de.debian.org/debian/dists/sid',
-      architectures: ['i386' ,'amd64']
+      architectures: %w[i386 amd64]
-      #components: ['main','restricted','universe','multiverse']
+      # components: ['main','restricted','universe','multiverse']
     }
   ]
 
@@ -101,4 +101,3 @@ Rails.application.configure do
   # Apply autocorrection by RuboCop to files generated by `bin/rails generate`.
   # config.generators.apply_rubocop_autocorrect_after_generate!
 end
-

config/environments/production.rb

@@ -53,7 +53,7 @@ Rails.application.configure do
   config.active_job.queue_adapter = :solid_queue
   config.solid_queue.connects_to = { database: { writing: :queue } }
   config.action_mailer.smtp_settings = {
-    address: Rails.application.credentials.smtp.server,
+    address: ENV['SMTP_SERVER'],
     port: 25,
     enable_starttls_auto: false
   }