cri-dockerd VS nerdctl

$ wget https://github.com/Mirantis/cri-dockerd/releases/download/v0.3.9/cri-dockerd-0.3.9.amd64.tgz $ tar zxvf cri-dockerd-0.3.9.amd64.tgz $ cd cri-dockerd $ sudo mkdir -p /usr/local/bin $ sudo install -o root -g root -m 0755 cri-dockerd/usr/local/bin/cri-dockerd $ mkdir foo; cd foo $ git clone [email protected]:Mirantis/cri-dockerd.git $ cd cri-dockerd $ sudo install packaging/systemd/* /etc/systemd/system $ sudo sed -i -e 's,/usr/bin/cri-dockerd,/usr/local/bin/cri-dockerd,' /etc/systemd/system/cri-docker.service $ sudo systemctl daemon-reload $ sudo systemctl enable --now cri-docker.socket

I installed cri-dockerd using this documentation https://github.com/Mirantis/cri-dockerd

99% of what you just said is completely incorrect. containerd is not a facade for Docker, in fact the Docker engine is a facade for containerd. The OCI spec is also not a facade for Docker, Docker is simply one application which can create OCI compliant images which can be executed by runtimes like runc. Kubernetes has zero facades for Docker, unless you count the optional open-source cri-dockerd.

https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/ Adjust netplan for static IP Adding br_netfilter and overlay to kernel Creating /etc/modules-load.d/k8s.conf with bridging and forwarding https://kubernetes.io/docs/setup/production-environment/container-runtimes/#forwarding-ipv4-and-letting-iptables-see-bridged-traffic Installing docker components https://kubernetes.io/docs/setup/production-environment/container-runtimes/#docker Installing cri-dockerd https://github.com/Mirantis/cri-dockerd Disabling swap https://graspingtech.com/disable-swap-ubuntu/ install kubeadm kubectl kubelet https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/

Im trying to learn how to set up kubernetes cluster with kubeadm. Im using official kubernetes documentation ( maybe there is a better source?). My goal is to set it up with cri-dockerd and systemd. And to be honest its quite hard task to do it. Informations are scattered arround with links and sometimes its hard to know the order which steps should be executed. I have 2 Virtualbox machines, connected together with NAT network. A master and worker node. I performed these steps on both of them: https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/ Adjust netplan for static IP Adding br_netfilter and overlay to kernel Creating /etc/modules-load.d/k8s.conf with bridging and forwarding https://kubernetes.io/docs/setup/production-environment/container-runtimes/#forwarding-ipv4-and-letting-iptables-see-bridged-traffic Installing docker components https://kubernetes.io/docs/setup/production-environment/container-runtimes/#docker Installing cri-dockerd https://github.com/Mirantis/cri-dockerd Disabling swap install kubeadm kubectl kubelet https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/ configure kubelet cgroup driver https://kubernetes.io/docs/tasks/administer-cluster/kubeadm/configure-cgroup-driver/ So currently im at the configuring cgroup driver. I tried to execute kubeadm init kubeadm-config.yaml but kubeadm found 2 CRI endpoints. So i tried to point the correct one with this command kubeadm join --cri-socket /var/run/cri-dockerd.sock but i got discover:Invalid value: ::: bootstrapToken or file must be set And now im completely lost. And also im confused is this a moment for installing CNI (probably i will try with Calico) for pod communication or should i start the cluster first?

But not to worry, you can still use Docker as a container runtime in Kubernetes using the cri-dockerd adapter. cri-dockerd provides a shim for Docker Engine that lets you control Docker via the Kubernetes CRI. ****

As of version 1.24, either one of the other supported runtimes (e.g. containerd or CRI-O) or, in case you still want to rely on Docker Engine, cri-dockerd must be used. Further information on precautions that may be necessary due to the removal of Dockershim is provided by Kubernetes in a guide.

Kubernetes requires a tool which implements the Container Runtime Interface, a standardized API for starting & managing containers. This is from 2015-2016[1].

For a while Kubernetes has included something called the "dockershim", it's own implementation of a CRI interface that, under the hood, calls Docker or Podman. There's also tools like kind[2] ("kubernetes in docker") that go further- not just hosting Kubernetes worker containers in Docker, but hosting the main kubernetes daemons also in Docker.

Kubernetes deprecated Dockershim, formally in December 2020, but is just throwing the switch now in the upcoming 1.24, expected mid-April[3]. A company Mirantis has pledged to take over support of Dockershim[4], and is calling the new effort "cri-dockerd"[5]. This should allow Kubernetes workers to continue to run via Docker or Podman.

Kind is unaffected, since it runs the main Kubernetes controllers in Docker, which then launch their own opencontainerd (one off the main CRI implementations) inside that Docker container, nested like, so no dockership/cri-dockerd is needed).

[1] https://kubernetes.io/blog/2016/12/container-runtime-interfa...

[2] https://kind.sigs.k8s.io/

[3] https://kubernetes.io/blog/2022/01/07/kubernetes-is-moving-o...

[4] https://www.mirantis.com/blog/mirantis-to-take-over-support-...

[5] https://github.com/Mirantis/cri-dockerd

What about the docker-cli? colima also ships with a docker-compatible cli to interact with containerd called nerdctl. We can execute the same docker cli commands like:

Using nerdctl: https://github.com/containerd/nerdctl

I'd really disagree that compose files are somehow one-shot, or blindly modified. To the contrary, really, we have them checked in with the source code. Upon deployment to the cluster, the (running) services will be intelligently updated or replaced (in a rolling manner, causing zero downtime). LXC might be more elegant, but I have no idea what simple, file-based format I could use to let engineers describe the environment their app should run in without compose.

I need something that even junior devs can start up with a single command, that can be placed in the VCS along with the code, and that will not require deep Linux knowledge to get running. Open for suggestions here, really.

Now since Kubernetes works off of containerd I'll be taking a different approach on handling container builds by using nerdctl and the buildkit that comes bundled with it. I'll do this on the amd64 control plane node since it's beefier than my Raspberry Pi workers for handling builds and build related services. Go ahead and download and unpack the latest nerdctl release as of writing (make sure to check the release page in case there's a new one):

That's why nerdctl, their cli binary, is so well named.

Well, it is indeed a good option. However, containerd is a good alternative that is growing even among developers. Please see: https://github.com/containerd/nerdctl

Nerdctl/containerd has IPFS support :)

https://github.com/containerd/nerdctl/blob/main/docs/ipfs.md

nerdctl supports IPFS for both image pulling and pushing, including encrypted images and eStargz lazy pulling. For building, the current method is a locally hosted translator so that the traditional pulls can be converted to work over IPFS. They even have docs on running it on k8s node, though if my reading is correct this isn't exactly a cloud native approach (running systemd services on each node...).