<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Windows-1252">
</head>
<body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; color: rgb(0, 0, 0); font-size: 14px; font-family: Calibri, sans-serif;">
<div>Hi,</div>
<div><br>
</div>
<div>I am working on Containerizing OpenStack in the Kolla project (<a href="http://launchpad.net/kolla">http://launchpad.net/kolla</a>). One of the key things we want to do over the next few months is add H/A support to our container tech. David Vossel had
suggested using systemctl to monitor the containers themselves by running healthchecking scripts within the containers. That idea is sound.</div>
<div><br>
</div>
<div>There is another technology called “super-privileged containers”. Essentially it allows more host access for the container, allowing the treatment of Pacemaker as a container rather than a RPM or DEB file. I’d like corosync to run in a separate container.
These containers will communicate using their normal mechanisms in a super-privileged mode. We will implement this in Kolla.</div>
<div><br>
</div>
<div>Where I am stuck is how does Pacemaker within a container control other containers in the host os. One way I have considered is using the docker —pid=host flag, allowing pacemaker to communicate directly with the host systemctl process. Where I am stuck
is our containers don’t run via systemctl, but instead via shell scripts that are executed by third party deployment software.</div>
<div><br>
</div>
<div>An example:</div>
<div>Lets say a rabbitmq container wants to run:</div>
<div><br>
</div>
<div>The user would run</div>
<div>kolla-mgr deploy messaging</div>
<div><br>
</div>
<div>This would run a small bit of code to launch the docker container set for messaging.</div>
<div><br>
</div>
<div>Could pacemaker run something like</div>
<div><br>
</div>
<div>Kolla-mgr status messaging</div>
<div><br>
</div>
<div>To control the lifecycle of the processes?</div>
<div><br>
</div>
<div>Or would we be better off with some systemd integration with kolla-mgr?</div>
<div><br>
</div>
<div>Thoughts welcome</div>
<div><br>
</div>
<div>Regards,</div>
<div>-steve</div>
</body>
</html>