Ubuntu 22.04 and Kubernetes recently Broke Compatibility with Each Other (and how to work around it)

Here’s another blog post today, that I’m creating for the same reason as the previous one. It took me a bit longer than I’d like to admit to figure this out, and if anyone else out there is wondering why their automated Kubernetes builds on Ubuntu 22.04 started failing on them suddenly for no apparent reason. Specifically, your Kubernetes cluster builds started failing on December 9th. (You literally can’t make this stuff up). So, after troubleshooting for countless hours I finally figured it out. I mentioned it to Jeff Geerling (yes THAT Jeff Geerling) and he mentioned I should write a blog post, in case it may help someone else. I figured that his suggestion was logical 🖖, so here it is.

What’s the problem I’m referring to? If you’re attempting to initialize a Kubernetes cluster on Ubuntu 22.04 and you see error messages that include output such as this:

CRI v1 runtime API is not implemented for endpoint

Or maybe even this:

unknown service runtime.v1.RuntimeService

Continue reading and I’ll let you know what the issue is, and how to fix it. I’ll also sneak in a quantum science reference and it’s going to be a good time.

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Quick Fix: “CrashLoopBackoff” While Building a Kubernetes Cluster with Ubuntu 22.04 on the Raspberry Pi

Normally, I like to make videos for Linux and Container-related things – it’s my favorite way to teach and inform. But some things don’t translate as well to videos, and this is one of them. Recently, I ran into an issue that I’ve been trying to solve for some time, where initializing a Kubernetes cluster on Ubuntu 22.04 seems to fail, specifically on the Raspberry Pi. Although I did ultimately find something while searching the web that led to my resolving this, search results were generally unhelpful, and neither was Stack Overflow. So what I wanted to do, was to create this article just so I could make sure that anyone else Googling for answers does find something.

Here’s the issue I ran into. For some reason, initializing Kubernetes clusters on Ubuntu 22.04 fails on the Raspberry Pi. More specifically, Flannel doesn’t seem to launch, with it stuck on “CrashLoopBackoff” most of the time. And not only that, the coredns pods will tend to stay stuck on “ContainerCreating” for eternity. Another symptom is that you’ll find errors in /var/log/syslog complaining about /run/flannel/subnet.env not being found. Oh, and another symptom. RPC errors will be mentioned in the syslog as well, and also complains about not being unable to create the sandbox.

Blogs and howto’s mention many “fixes” for this issue, but for me I didn’t have any luck there. Some of them will have you create the /run/flannel/subnet.env file manually – but you shouldn’t have to do that, it’s not your job. (That file should be created automatically). I’ve seen at least one blog post mention the order matters regarding when you apply Flannel (nonsense) and not to be outdone, the classic “remove the directory and reboot” trick that also never seemed to work for me.

So, what’s the fix?

Are you ready?

Here you go…

sudo apt install linux-modules-extra-raspi

Yeah, that’s literally it. I’m not kidding. See for yourself. You’re all set. Profit. Enjoy. I know, right?!

Thanks to this completely unrelated bug report that gave me the idea to install this package and ultimately led to my writing this article. It’s my sincere hope that this blog post finds its way into the Google searches of whoever out there needs this.

I wrote an Entire Book with Free and Open-Source Software

LibreOffice, an office suite from the Document Foundation contains all the features you’d expect in an office suite, including (but not limited to) the ability to create text, spreadsheet, and presentation documents. So why aren’t more people using it? In this video, Jay discusses some of the unreasonable stigma LibreOffice suffers from. Is LibreOffice inferior to Microsoft Office? Well, Jay wrote an entire book with LibreOffice – and naturally, has some thoughts!

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Want to help LearnLinuxTV?

Hello everyone! I wanted to take a moment and create a quick post to see if anyone is interested in helping out the channel. I have a number of you helping out on Patreon, and that’s awesome, I really appreciate it! But there’s also some non-monetary assistance that could help out too, so if you want to give back and you don’t have the budget to justify becoming a Patron, there’s some additional ways that you might consider as well. Read on to find out about some additional ways you can potentially help out.

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