Diagnosing problems with an OpenStack deployment

Mon 09 March 2015 by Lars Kellogg-Stedman Tags openstack

I recently had the chance to help a colleague debug some problems in his OpenStack installation. The environment was unique because it was booting virtualized aarch64 instances, which at the time did not have any PCI bus support...which in turn precluded things like graphic consoles (i.e., VNC or ...

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Converting hexadecimal ip addresses to dotted quads with Bash

Sun 08 March 2015 by Lars Kellogg-Stedman Tags bash docker

This is another post that is primarily for my own benefit for the next time I forget how to do this.

I wanted to read routing information directly from /proc/net/route using bash, because you never know what may or may not be available in the minimal environment of ...

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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:

https://github.com/larsks/pacemaker-tools/

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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