From: Matt Palmer <mpalmer@hezmatt.org>
Date: Tue, 19 Apr 2016 20:05:43 +0000 (+1000)
Subject: Assign a stable but unique MAC address to each container
X-Git-Url: https://vcs.fsf.org/?a=commitdiff_plain;h=8cf19a402d4ba308f858461e3a5e0390f96eff81;p=discourse_docker.git

Assign a stable but unique MAC address to each container

This does Very Good Things for IPv6 addresses (at least on versions of
Docker that aren't [buggy](https://github.com/docker/docker/issues/17739)).
You get an IPv6 address which doesn't change on each reboot, and at the same
time you don't get different containers having the same IPv6 address at
different times.  Wins all round!
---

diff --git a/launcher b/launcher
index ed91e79..0a77911 100755
--- a/launcher
+++ b/launcher
@@ -528,9 +528,12 @@ run_start(){
      # docker added more hostname rules
      hostname=${hostname/_/-}
 
+     mac_address="--mac-address $(echo $hostname | md5sum | sed 's/^\(..\)\(..\)\(..\)\(..\)\(..\).*$/02:\1:\2:\3:\4:\5/')"
+
      set -x
      $docker_path run $user_args $links $attach_on_run $restart_policy "${env[@]}" -h "$hostname" \
-        -e DOCKER_HOST_IP=$docker_ip --name $config -t $ports $volumes $docker_args $run_image $boot_command
+        -e DOCKER_HOST_IP=$docker_ip --name $config -t $ports $volumes $mac_address $docker_args \
+        $run_image $boot_command
 
    )
    exit 0