containerd VS flannel

Containerd and nerdctl

Kubernetes on the backend used to utilize docker for much of its container runtime solutions. One of the modular features of Kubernetes is the ability to utilize a Container Runtime Interface or CRI. The problem was that Docker didn't really meet the spec properly and they had to maintain a shim to translate properly. Instead users could utilize the popular containerd or cri-o runtimes. These follow the Open Container Initiative or OCI's guidelines on container formats.

Container Engine: A runtime that executes and manages containers. Docker and containerd are popular container engines.

Multiple container runtimes are supported, like conatinerd, cri-o, or other CRI compliant runtimes.

This is a failed attempt to upstream part of containerd changes: https://github.com/containerd/containerd/pull/8789

Other part of containerd changes waits for gods-know-what: https://github.com/containerd/containerd/pull/9054

But I haven't gave up yet.

containerd is required by kubernetes to handle containers on its behalf. A big thanks to the HostAfrica blog for the information on setting containerd up for debain. So the containerd install will need to happen on both the WSL2 instance and the Raspberry Pis. For WSL2 you can just install containerd directly:

The context deadline exceeded: unknown is also in containerd, and is a known problem.

Get:1 https://download.docker.com/linux/ubuntu focal/stable amd64 containerd.io amd64 1.6.21-1 [28.3 MB]

Docker Desktop adds a bunch of stuff to simplify local development and that’s why it has a larger memory footprint. You don’t use that when deploying but something like https://containerd.io/.

$ kubectl apply -f https://github.com/flannel-io/flannel/releases/latest/download/kube-flannel.yml

--pod-network=10.244.0.0/16: This is the default CIDR for flannel, and also avoids a conflict with my internal network if calico is used (which is the plan)

The installation of K8s id done by kubeadm. In this installation Containerd is used as CRI and flannel is used as CNI.

K8s is installed through kubeadm ad uses Containerd as CRI and Flannel as CNI. You can also install longhorn for the persistent storage and nginx ingress controller for the ingress rules.

This terraform module will deploy a high available Kubernetes (K8s) cluster on Amazon AWS, using mixed on-demand and spot instances. K8s is installed through kubeadm ad usesContainerd as CRI and Flannel as CNI. You can also install longhorn for the persistent storage and nginx ingress controller for the ingress rules. Please note, this is only an example on how to Deploy a Kubernetes cluster. For a production environment you should use EKS or ECS.

I don't use flannel but perhaps check this old issue: https://github.com/flannel-io/flannel/issues/663

It is definitively not normal behaviour. Cluster-internal subnets should be reachable from any node. Not being able to do so is a typical symptom of missing or misconfigured CNI. For flannel did you check this page?

Ask on Github.

I have Ubuntu 20.x and 21.x installed in my cluster, mostly because I am familiar with Ubuntu and figured the latest LTS versions would be a good idea to use for docker swarm and now kubernetes.... But there is a kernel bug, (k3s issue link and flannel issue link) with VXLAN that makes the default flannel container networking interface not work..... So I decided to Calico as the CNI to experiment with it, but I have been running to issues with BIRD is not ready: errors on only 2 of my nodes..... Which is an improvement then all of my nodes having the error like a couple of days ago.... but it is frustrating that only 2 have the error....