ssh allows you to run a command on a remote machine. You may want to use a shell variable in a remote command. You have to be aware of when that variable gets evaluated.
Continue readingShell variable expansion across ssh sessions
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Category Archives: Sysadmin
Ironic Clean PXE failure
One of our ironic baremetal nodes was suffering a cleaing failure. Fixing it was easy…once we knew the cause/
Continue readingA simple HTML table for comma separated variable files.
Enough of us are looking at the cluster that I want an easy to read snapshot of the node state. So, I convert the csv output of the openstack command into a simple HTML table.
Continue readingSelect only the Jades
Some custom jq for RegEx selection of OpenStack Ironic baremetal nodes. Our Server types show up in their names. I want to be able to build lists of only the Mt. Jade Servers, which have names that look like this:
jade09-r097
openstack baremetal node list --sort provision_state:asc -c UUID -c Name -f json | jq '.[] | select(.Name | test("jade."))' |
What Nodes are broken?
While I tend to think about the nodes in OpenStack term, the people that physically move the servers around are more familiar with their IPMI address. We have several nodes that are not responding to IPMI requests. Some have been put into the manageable state, some are in error.
Here’s the query I used to list them.
Legible Error traces from openstack server show
If an OpenStack server (Ironic or Nova) has an error, it shows up in a nested field. That field is hard to read in its normal layout, due to JSON formatting. Using jq to strip the formatting helps a bunch
The nested field is fault.details.
The -r option strips off the quotes.
Continue readingDebugging a Clean Failure in Ironic
Table of contents
My team is running a small OpenStack cluster with reposnsibility for providing bare metal nodes via Ironic. Currently, we have a handful of nodes that are not usable. They show up as “Cleaning failed.” I’m learning how to debug this process.
Continue readingIPMI triggering a PXE install
To reinstall a machine that is managed by IPMI, you tell it to PXE boot and then power cycle. Here are my notes.
Continue readingKeeping Kdenlive from crashing
QT_QPA_PLATFORM=xcb kdenlive |
I don’t understand, yet, why this works, but it does. Thanks to this post
QJackCtl and Pipewire
It took me a few tries, but I finally got a passable demo/tutorial about Pipewire and QJackCtl.
Here’s the final version. Well, final for now.
Here’s the version before that that got hit by a copyright claim and thus was not visible in Canada. I chose the “auto edit” option to remove the copywritten material. I think that means that you don’t see how you can feed browser audio back into itself. I’ve not watched it since it got cut.
Here is the original Camcorder version. This was really the approach I wanted to take, with the camera picking up the same audio that I was hearing. But the video was unwatchable.