For various reasons I wanted to play with docker containers backed by persistent Ceph storage. rexray seemed like the way to do that, so here are my notes on getting that working… First off, I needed to install rexray: root@labosa:~/rexray# curl -sSL https://dl.bintray.com/emccode/rexray/install | sh Selecting previously unselected package rexray. (Reading database … 177547 files…
Author: mikal
So you want to setup a Ceph dev environment using OSA
Support for installing and configuring Ceph was added to openstack-ansible in Ocata, so now that I have a need for a Ceph development environment it seems logical that I would build it by building an openstack-ansible Ocata AIO. There were a few gotchas there, so I want to explain the process I used. First off,…
The Collapsing Empire
This is a fun fast read, as is everything by Mr Scalzi. The basic premise here is that of a set of interdependent colonies that are about to lose their ability to trade with each other, and are therefore doomed. Oh, except they don’t know that and are busy having petty trade wars instead. It…
Python3 venvs for people who are old and grumpy
I’ve been using virtualenvwrapper to make venvs for python2 for probably six or so years. I know it, and understand it. Now some bad man (hi Ramon!) is making me do python3, and virtualenvwrapper just isn’t a thing over there as best as I can tell. So how do I make a venv? Its really…
Things I read today: the best description I’ve seen of metadata routing in neutron
I happened upon a thread about OVN’s proposal for how to handle nova metadata traffic, which linked to this very good Suse blog post about how metadata traffic is routed in neutron. I’m just adding the link here because I think it will be useful to others. The OVN proposal is also an interesting read.
Nova vendordata deployment, an excessively detailed guide
Nova presents configuration information to instances it starts via a mechanism called metadata. This metadata is made available via either a configdrive, or the metadata service. These mechanisms are widely used via helpers such as cloud-init to specify things like the root password the instance should use. There are three separate groups of people who…
Giving serial devices meaningful names
This is a hack I’ve been using for ages, but I thought it deserved a write up. I have USB serial devices. Lots of them. I use them for home automation things, as well as for talking to devices such as the console ports on switches and so forth. For the permanently installed serial devices…
A pythonic example of recording metrics about ephemeral scripts with prometheus
In my previous post we talked about how to record information from short lived scripts (I call them ephemeral scripts by the way) with prometheus. The example there was a script which checked the SMART status of each of the disks in a machine and reported that via pushgateway. I now want to work through…
Game review: Betrayal at House on the Hill
At the insistence of Uncle David, we had to try this one again after he filed a formal protest at our previous review. I must say this game went much better than last time… David: oh boy I want to be the traitor. Shit I’m not. Then I died. First loser! Mikal: this went much…
Recording performance information from short lived processes with prometheus
Now that I’m recording basic statistics about the behavior of my machines, I now want to start tracking some statistics from various scripts I have lying around in cron jobs. In order to make myself sound smarter, I’m going to call these short lived scripts “ephemeral scripts” throughout this document. You’re welcome. The promethean way…