Preventing Kubernetes from pulling the pause image from the internet

https://kyle.cascade.family/posts/preventing-kubernetes-from-pulling-the-pause-image-from-the-internet/

by meatmanek • 9 months ago

97 52 9 months ago

kyle.cascade.family

cmckn3• 9 months ago

It bugs me that this implementation detail of containerd has leaked to such an extent. This should be part of the containerd distribution, and should not be pulled at runtime.

Instead of just swapping out the registry, try baking it into your machine image.

chupasaurus2• 9 months ago

It's implementation of cri plugin.

This should be part of the containerd distribution

containerd is not the only CRI runtime out there.

cmckn3• 9 months ago

It's implementation of cri plugin.

Right, that’s the point. A user of the CRI should not have to care about this implementation detail.

containerd is not the only CRI runtime out there.

Any CRI that needs a pause executable should come with one.

spwa4• 9 months ago

More general one would wish that Kubernetes had a few extra ways to get images, so you could grow on a scale from "minimal infrastructure" to "fully CI/CD". Starting with just sending the image in the RPC itself or even just on local disk (you figure out how to get it there), all the way up to registries with tightly controlled versioning.

p_l• 9 months ago

It's possible to do that, as kubernetes only passes the image information to CRI.

You can also setup a separate service to "push" images directly to your container runtime, someone even demoed one in Show HN post some time ago I think.

kawsper• 9 months ago

Relying on an hosted image also caused some disruptions for Nomad (the scheduler from Hashicorp), because the default pause image was hosted at gcr.io which google killed, and it moved to registry.k8s.io.

The nomad team made this configurable afterwards.

verdverm• 9 months ago

That nomad was hit with this after years of notice and deprecation extension, seems a sign of serious maintenance issues

yencabulator• 9 months ago

It's almost as if Docker (the company) wants it this way.

fred_is_fred• 9 months ago

I've used k8s before a lot and at several companies. I am convinced that 99.9% of the people who use it should not be. But it's more fun than deploying VM images at least.

kachapopopow3• 9 months ago

I use k3s for my home and for dev envs I think it's completely fine especially when it comes to deployment documentation.

I am way more comfortable managing a system that is k3s rather than something that is still using tmux that gets wiped every reboot.

Well... it's what I would have said until bitnami pulled the rug and pretty much ruined the entire ecosystem as now you don't have a way to pull something that you know is trusted with similar configuration and all from a single repository which makes deployments a pain in the ass.

However, on the plus side I've just been creating my own every time I need one with the help of claude using bitnami as reference and honestly it doesn't take that much more time and keeping them up to date is relatively easy as well with ci automations.

Imustaskforhelp2• 9 months ago

I am way more comfortable managing a system that is k3s rather than something that is still using tmux that gets wiped every reboot.

Thoughts on Tmux-resurrect[1] , it can even resurrect programs running inside of it as well. It feels like it can as such reduce complexity from something like k3s back to tmux. What are your thoughts on it?

[1] https://github.com/tmux-plugins/tmux-resurrect?tab=readme-ov...

yupyupyups• 9 months ago

The situation with bitnami is getting fixed, but it takes time for all the holes to be plugged.

I knew bitnami were trouble when I saw their paid tier prices. Relevant article: https://devoriales.com/post/402/from-free-to-fee-how-broadco...

Oh, and it's owned by Broadcom.

SlavikCA2• 9 months ago

I'm running k3s at home on single node with local storage. Few blogs, forum, minIO.

Very easy, reliable.

Without k3s I would have use Docker, but k3s really adds important features: easier to manage network, more declarative configuration, bundled Traefik...

So, I'm convinced that quite a few people can happily and efficiently use k8s.

In the past I used other k8s distro (Harvester) which was much more complicated to use and fragile to maintain.

esseph2• 9 months ago

Check out Talos Linux if you haven't already, it's pretty cool (if you want k8s).

Chilinot2• 9 months ago

What makes you come to that conclusion?

cyberpunk• 9 months ago

They’ve never worked on a real soa/multi-team/microservices project with more than 20 separate deployments before and assumes no one else does.

pjmlp• 9 months ago

Same here, I went through a few projects since 2021 where doing Kubernetes setups were part of my role on the consulting project, and I would say prefer managed containers solutions, e.g. Azure Web Apps, or when running locally plain systemd or Docker Compose.

Anything else, most companies aren't Web scale enough to set their full Kubernetes clusters with failover regions from scratch.

Gabrys1• 9 months ago

I like Docker(compose) + Portainer for small deployments

nneonneo• 9 months ago

O/T, but I'm getting a cert error on this page - wonder if it's just me or if this site is just serving a weird cert. Looks like it's signed by some Fortinet appliance - maybe I'm getting MITMed? Would be kind of exciting/frightening if so.

EDIT: I loaded the page from a cloud box, and wow, I'm getting MITMed! Seems to only be for this site, wonder if it's some kind of sensitivity to the .family TLD.

gregoryl• 9 months ago

Ooft. If it helps, this is the PEM I'm getting. LetEncrypt signed.

nodesocket• 9 months ago

Nice to know, though I wonder how many companies are really using all private images? I've certainly had a client running their own Harbor instance, but almost all others pulled from Docker Hub or Github (ghcr.io).

redrove• 9 months ago

Pretty much all enterprises are using their own ECR/GCR/ACR.

j-scott2• 9 months ago

I work on the container registry team at my current company running a custom container registry service!

hanikesn• 9 months ago

How does this require a whole team? Unless you're working at a hyperscaler

wvh• 9 months ago

Lots of medical and governmental organisations are not allowed to run in public cloud environments. It's part of my job to help them get set up. However, in reality that often boils down to devs wining about adding a registry to Harbor to cache; nobody is going to recompile base images and read through millions of lines of third party code.

A lot of security is posturing and posing to legally cover your ass by following an almost arbitrary set of regulations. In practice, most end up running the same code as the rest of us anyway. People need to get stuff done.

rcbdev• 9 months ago

The Public Sector and anyone concerned with compliance under the Cyber Resilience Act should really use their own private image store. Some do, some don't.

philipallstar• 9 months ago

Some people run Artifactory as a cache in front of Docker Hub etc, which allows some governance

arccy• 9 months ago

I think once your eng org > 300 people and you have a dedicated infra and security team, it's going to be on their radar to do at some point.

nevon• 9 months ago

Just to save someone 5 minutes of research, if you are using the EKS AMIs based on AL2023 or Bottlerocket, this is already done for you by pointing to an image on ECR. At least on Bottlerocket, I haven't checked AL2023, the image is baked into the AMI so you don't even need to pull it from ECR.

Chilinot2• 9 months ago

Thank you, was just about to task my team with figuring out how affected we are by this.

cmckn3• 9 months ago

We removed the image registry dependency on AL2023 as well. :)

https://github.com/awslabs/amazon-eks-ami/pull/2000

rcarmo2• 9 months ago

I believe this has been patched time and time again in on-premises variants like OpenShift. Curious to check if it’s there in small variants like microk8s, k3s, etc., as I’m considering moving a few offline services to Talos.

anttiharju2• 9 months ago

Talos' KubeSpan is backed by Sidero-hosted disovery service that cannot be self-hosted without a commercial license

rcarmo2• 9 months ago

Hmmm. So I need to find something equivalent as a base OS. Maybe it's time to do Fedora Core.

hexo• 9 months ago

Easy. Dont use kubernetes. You'll thank me later.

preisschild• 9 months ago

Yeah that pause image was really annoying when I was hosting a k8s cluster on Hetzner, since the `registry.k8s.io` -registry was blocking some Hetzner IPs, since its hosted on Google.

ralgozino• 9 months ago

I went down this rabbit hole not so long ago too.

There was a discussion open on containerd's GitHub on removing the dependency on the pause image but it has been closed as won't fix: https://github.com/containerd/containerd/issues/10505

Also, if you are using kubeadm to create your cluster, beware that kubeadm may be pre-pulling a different pause image if it does not match your containerd configuration: https://github.com/kubernetes/kubeadm/issues/2020

thiht• 9 months ago

This is insane, am I the only one being shocked to learn about this? This reeks of bad engineering, is there at least a plan to make this go away by embedding "pause" with the distribution?

Preventing Kubernetes from pulling the pause image from the internet

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