From e448e403ba4c92b483f4fe2a308b3d3afd4d5635 Mon Sep 17 00:00:00 2001
From: Ralf Teusner <ralf.teusner@hpi.uni-potsdam.de>
Date: Tue, 21 Apr 2015 18:28:34 +0200
Subject: [PATCH] restart containers if they are running for more than 15
 minutes (900 seconds)

---
 lib/docker_client.rb          |  1 +
 lib/docker_container_mixin.rb |  4 ++++
 lib/docker_container_pool.rb  | 20 +++++++++++++++++++-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/lib/docker_client.rb b/lib/docker_client.rb
index 95b89e50..8bb6ce4f 100644
--- a/lib/docker_client.rb
+++ b/lib/docker_client.rb
@@ -53,6 +53,7 @@ class DockerClient
     local_workspace_path = generate_local_workspace_path
     FileUtils.mkdir(local_workspace_path)
     container.start(container_start_options(execution_environment, local_workspace_path))
+    container.start_time = Time.now
     container
   rescue Docker::Error::NotFoundError => error
     destroy_container(container)
diff --git a/lib/docker_container_mixin.rb b/lib/docker_container_mixin.rb
index a8d3c8a4..fde9fe5b 100644
--- a/lib/docker_container_mixin.rb
+++ b/lib/docker_container_mixin.rb
@@ -1,4 +1,8 @@
 module DockerContainerMixin
+
+  attr_accessor :start_time
+  attr_accessor :status
+
   def binds
     json['HostConfig']['Binds']
   end
diff --git a/lib/docker_container_pool.rb b/lib/docker_container_pool.rb
index 8823d989..47a8bf5c 100644
--- a/lib/docker_container_pool.rb
+++ b/lib/docker_container_pool.rb
@@ -3,6 +3,8 @@ require 'concurrent/timer_task'
 require 'concurrent/utilities'
 
 class DockerContainerPool
+  TIME_TILL_RESTART = 900
+
   @containers = ThreadSafe::Hash[ExecutionEnvironment.all.map { |execution_environment| [execution_environment.id, ThreadSafe::Array.new] }]
   #as containers are not containing containers in use
   @all_containers = ThreadSafe::Hash[ExecutionEnvironment.all.map { |execution_environment| [execution_environment.id, ThreadSafe::Array.new] }]
@@ -22,12 +24,28 @@ class DockerContainerPool
   end
 
   def self.return_container(container, execution_environment)
+    container.status = 'available'
     @containers[execution_environment.id].push(container)
   end
 
   def self.get_container(execution_environment)
     if config[:active]
-      @containers[execution_environment.id].try(:shift) || nil
+      container = @containers[execution_environment.id].try(:shift) || nil
+
+      if((Time.now - container.start_time).to_i.abs > TIME_TILL_RESTART)
+        # remove container from @all_containers
+        @all_containers[execution_environment.id]-=[container]
+
+        # destroy container
+        DockerClient.destroy_container(container)
+
+        # create new container and add it to @all_containers. will be added to @containers on return_container
+        container = create_container(@execution_environment)
+        @all_containers[execution_environment.id]+=[container]
+      end
+      container.status = 'used'
+      container
+
     else
       create_container(execution_environment)
     end