implemented pooling for Docker containers

config/docker.yml.erb

@@ -1,5 +1,8 @@
 default: &default
   connection_timeout: 3
+  pool:
+    active: false
+    interval: 60
   ports: !ruby/range 4500..4600
 
 development:
@@ -9,6 +12,8 @@ development:
 
 production:
   <<: *default
+  pool:
+    active: true
   workspace_root: <%= Rails.root.join('tmp', 'files', Rails.env) %>
 
 test:

config/initializers/docker.rb

@@ -0,0 +1,3 @@
+DockerClient.initialize_environment
+DockerContainerPool.start_refill_task if DockerContainerPool.config[:active]
+at_exit { DockerContainerPool.clean_up } unless Rails.env.test?

config/locales/de.yml

@@ -13,6 +13,7 @@ de:
         help: Hilfetext
         name: Name
         permitted_execution_time: Erlaubte Ausführungszeit (in Sekunden)
+        pool_size: Docker-Container-Pool-Größe
         run_command: Ausführungsbefehl
         test_command: Testbefehl
         testing_framework: Testing-Framework

config/locales/en.yml

@@ -13,6 +13,7 @@ en:
         help: Help Text
         name: Name
         permitted_execution_time: Permitted Execution Time (in Seconds)
+        pool_size: Docker Container Pool Size
         run_command: Run Command
         test_command: Test Command
         testing_framework: Testing Framework