From 516d475f16dde60e114c1528926df2d3f70e3593 Mon Sep 17 00:00:00 2001
From: Seth Vargo <sethvargo@gmail.com>
Date: Fri, 10 Jul 2015 11:32:02 -0600
Subject: [PATCH] Checksum args to each docker container in local data

This allows Vagrant to calculate if a container's arguments (such as the run
arguments) have changed in the Vagrantfile since the original run.

Fixes GH-3055
---
 plugins/provisioners/docker/client.rb | 76 ++++++++++++++++++++++-----
 templates/locales/en.yml              |  4 +-
 2 files changed, 65 insertions(+), 15 deletions(-)

diff --git a/plugins/provisioners/docker/client.rb b/plugins/provisioners/docker/client.rb
index 6f0e39ad3..391c76395 100644
--- a/plugins/provisioners/docker/client.rb
+++ b/plugins/provisioners/docker/client.rb
@@ -59,7 +59,15 @@ module VagrantPlugins
         id = "$(cat #{config[:cidfile]})"
 
         if container_exists?(id)
-          start_container(id)
+          if container_args_changed?(config)
+            @machine.ui.info(I18n.t("vagrant.docker_restarting_container",
+              name: config[:name],
+            ))
+            stop_container(id)
+            create_container(config)
+          else
+            start_container(id)
+          end
         else
           create_container(config)
         end
@@ -75,27 +83,41 @@ module VagrantPlugins
         end
       end
 
+      def stop_container(id)
+        @machine.communicate.sudo %[
+          docker stop #{id}
+          docker rm #{id}
+        ]
+      end
+
       def container_running?(id)
         lookup_container(id)
       end
 
+      def container_args_changed?(config)
+        path = container_data_path(config)
+        return true if !path.exist?
+
+        args = container_run_args(config)
+        sha  = Digest::SHA1.hexdigest(args)
+        return true if path.read.chomp != sha
+
+        return false
+      end
+
       def create_container(config)
-        name = config[:name]
+        args = container_run_args(config)
 
-        # If the name is the automatically assigned name, then
-        # replace the "/" with "-" because "/" is not a valid
-        # character for a docker container name.
-        name = name.gsub("/", "-") if name == config[:original_name]
-
-        args = "--cidfile=#{config[:cidfile]} "
-        args << "-d " if config[:daemonize]
-        args << "--name #{name} " if name && config[:auto_assign_name]
-        args << "--restart=#{config[:restart]}" if config[:restart]
-        args << " #{config[:args]}" if config[:args]
         @machine.communicate.sudo %[
           rm -f #{config[:cidfile]}
-          docker run #{args} #{config[:image]} #{config[:cmd]}
+          docker run #{args}
         ]
+
+        name = container_name(config)
+        sha  = Digest::SHA1.hexdigest(args)
+        container_data_path(config).open("w+") do |f|
+          f.write(sha)
+        end
       end
 
       def lookup_container(id, list_all = false)
@@ -110,6 +132,33 @@ module VagrantPlugins
         end
       end
 
+      def container_name(config)
+        name = config[:name]
+
+        # If the name is the automatically assigned name, then
+        # replace the "/" with "-" because "/" is not a valid
+        # character for a docker container name.
+        name = name.gsub("/", "-") if name == config[:original_name]
+        name
+      end
+
+      def container_run_args(config)
+        name = container_name(config)
+
+        args = "--cidfile=#{config[:cidfile]} "
+        args << "-d " if config[:daemonize]
+        args << "--name #{name} " if name && config[:auto_assign_name]
+        args << "--restart=#{config[:restart]}" if config[:restart]
+        args << " #{config[:args]}" if config[:args]
+
+        "#{args} #{config[:image]} #{config[:cmd]}".strip
+      end
+
+      def container_data_path(config)
+        name = container_name(config)
+        @machine.data_dir.join("docker-#{name}")
+      end
+
       protected
 
       # This handles outputting the communication data back to the UI
@@ -125,7 +174,6 @@ module VagrantPlugins
           @machine.ui.info(data.chomp, options)
         end
       end
-
     end
   end
 end
diff --git a/templates/locales/en.yml b/templates/locales/en.yml
index b906e8f0b..87373d758 100644
--- a/templates/locales/en.yml
+++ b/templates/locales/en.yml
@@ -141,7 +141,9 @@ en:
       Building Docker images...
     docker_running: |-
       -- Container: %{name}
-    docker_starting_containers:
+    docker_restarting_container: |-
+      -- Detected changes to container '%{name}', restarting...
+    docker_starting_containers: |-
       Starting Docker containers...
     inserted_key: |-
       Key inserted! Disconnecting and reconnecting using new SSH key...