Visualizing Pacemaker resource constraints

Tue 24 February 2015 by Lars Kellogg-Stedman Tags pacemaker visualization

If a picture is worth a thousand words, then code that generates pictures from words is worth...uh, anyway, I wrote a script that produces dot output from Pacemaker start and colocation constraints:

You can pass this output to graphviz to create visualizations of your …

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Stupid Pacemaker XML tricks

Thu 19 February 2015 by Lars Kellogg-Stedman Tags pacemaker xml xpath

I've recently spent some time working with Pacemaker, and ended up with an interesting collection of XPath snippets that I am publishing here for your use and/or amusement.

Check if there are any inactive resources

pcs status xml |
  xmllint --xpath '//resource[@active="false"]' - >&/dev/null &&
  echo "There are inactive …
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Unpacking Docker images with Undocker

Fri 13 February 2015 by Lars Kellogg-Stedman Tags docker

In some ways, the most exciting thing about Docker isn't the ability to start containers. That's been around for a long time in various forms, such as LXC or OpenVZ. What Docker brought to the party was a convenient method of building and distributing the filesystems necessary for running containers …

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Installing nova-docker with devstack

Wed 11 February 2015 by Lars Kellogg-Stedman Tags openstack docker devstack

This is a long-form response to this question, and describes how to get the nova-docker driver up running with devstack under Ubuntu 14.04 (Trusty). I wrote a similar post for Fedora 21, although that one was using the RDO Juno packages, while this one is using devstack and the …

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External networking for Kubernetes services

Tue 10 February 2015 by Lars Kellogg-Stedman Tags docker kubernetes

I have recently started running some "real" services (that is, "services being consumed by someone other than myself") on top of Kubernetes (running on bare metal), which means I suddenly had to confront the question of how to provide external access to Kubernetes hosted services. Kubernetes provides two solutions to …

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