Any new technology requires a mental effort to understand. When trying to automate the boring stuff, one decision I have to make is whether to use straight shell scripting or whether to perform that operation using Ansible. What I want to do is look at a simple Ansible playbook I have written, and then compare what the comparable shell script would look like to determine if it would help my team to use Ansible or not in this situation.
Continue readingAfter you get something working, you find you might have missed a step in documenting how you got that working. You might have installed a package that you didn’t remember. Or maybe you set up a network connection. In my case, I find I have often brute-forced the SSH setup for later provisioning. Since this is done once, and then forgotten, often in the push to “just get work done” I have had to go back and redo this (again usually manually) when I get to a new machine.
To avoid this, I am documenting what I can do to get a new machine up and running in a state where SSH connections (and forwarding) can be reliably run. This process should be automatable, but at a minimum, it should be understood.
Much of my work is done on machines that are only on load to me, not permanently assigned. Thus, I need to be able to provision them quickly and with a minimum of fuss. One action I routinely need to do is to check code out of a git server, such as gitlab.com. We use ssh keys to authenticate to gitlab. I need a way to do this securely when working on a remote machine. Here’s what I have found
We have an internal system for allocating hardware to developers on a short term basis. While the software does have a web API, it is not enabled by default, nor in our deployment. Thus, we end up caching a local copy of the data about the machine. The machine names are a glom of architecture, and location. So I make a file with the name of the machine, and a symlink to the one I am currently using.
Continue readingwhen run from inside a console/ssh session will tell you the ipmi address of the machine you are on.
Today I was reminded how easy it is to get fixed in your thinking.
The short lessons learned: if the Hostname fails (due to SSL) try the IP address.
Longer story:
Continue readingIn a recent article, I saw yet another example of using grep to pull information out of xml, and then to manually look for a field. However, XML is structured, and with XPath, we can pull out exactly what we need.
virsh dumpxml fedora-server-36 | xmllint --xpath "//domain/devices/disk[@device='disk']" - |
That will produce output like this:
<disk type="file" device="disk"> <driver name="qemu" type="qcow2" discard="unmap"/> <source file="/var/lib/libvirt/images/fedora-server-36.qcow2"/> <target dev="vda" bus="virtio"/> <address type="pci" domain="0x0000" bus="0x05" slot="0x00" function="0x0"/> </disk> |
Note that I did more in my XPath than required by the original article. I wanted to show an example of querying based on an attribute inside the selected node.
Update: Here is an example for what is done later in the article: pull the path out of the pool xml.
virsh pool-dumpxml default | xmllint --xpath "//pool/target/path/text()" - /var/lib/libvirt/images |
To make the AARCH64 ipxe process work using bifrost, I had to
git clone https://github.com/ipxe/ipxe.git cd ipxe/src/ make bin-arm64-efi/snponly.efi ARCH=arm64 sudo cp bin-arm64-efi/snponly.efi /var/lib/tftpboot/ipxe.efi |
This works for the Ampere reference implementation servers that use a Mellanox network interface card, which supports (only) snp.
(With apologies to Bergman and Legrand)
I need to modify how the ipxe container mounts directories. Why? AARCH64 iPXE stuff. Specifically, I need to get my own version of a file into the directory that a container mounts when it is running. How do I do that? I don’t know yet, so I am going to look.
Continue readingFor the past week I worked on getting a Ironic standalone to run on an Ampere AltraMax server in our lab. As I recently was able to get a baremetal node to boot, I wanted to record the steps I went through.
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