plugins VS cni

containernetworking-plugins will install the Container Network Interface plugins which are required by kubernetes networking solutions to operate. Now the bundled containerd config doesn't quite work well with what kubernetes requires so we'll make changes to it:

mkdir -p /opt/cni/bin/ && sudo wget https://github.com/containernetworking/plugins/releases/download/v1.1.1/cni-plugins-linux-amd64-v1.1.1.tgz && tar Cxzvf /opt/cni/bin cni-plugins-linux-amd64-v1.1.1.tgz && sed -i 's/disabled_plugins \=/#disabled_plugins \=/g' /etc/containerd/config.toml

curl -L -o cni-plugins.tgz [https://github.com/containernetworking/plugins/releases/download/v1.0.1/cni-plugins-linux-amd64-v1.0.1.tgz](https://github.com/containernetworking/plugins/releases/download/v1.0.1/cni-plugins-linux-amd64-v1.0.1.tgz)

root@localhost:~# curl -L -o cni-plugins.tgz "https://github.com/containernetworking/plugins/releases/download/v1.0.0/cni-plugins-linux-$( [$(uname -m) = aarch64] && echo arm64 || echo amd64)"-v1.0.0.tgz root@localhost:~# mkdir -p /opt/cni/bin root@localhost:~# tar -C /opt/cni/bin -xzf cni-plugins.tgz root@localhost:~# echo 1 | tee /proc/sys/net/bridge/bridge-nf-call-arptables 1 root@localhost:~# echo 1 | tee /proc/sys/net/bridge/bridge-nf-call-ip6tables 1 root@localhost:~# echo 1 | tee /proc/sys/net/bridge/bridge-nf-call-iptables 1

root@kubefire:~# kubefire install INFO[2022-11-11T11:46:13Z] downloading https://raw.githubusercontent.com/innobead/kubefire/v0.3.8/scripts/install-prerequisites.sh to save /root/.kubefire/bin/v0.3.8/install-prerequisites.sh force=false version=v0.3.8 INFO[2022-11-11T11:46:14Z] running script (install-prerequisites.sh) version=v0.3.8 INFO[2022-11-11T11:46:14Z] running /root/.kubefire/bin/v0.3.8/install-prerequisites.sh version=v0.3.8 INFO[2022-11-11T11:46:14Z] + TMP_DIR=/tmp/kubefire INFO[2022-11-11T11:46:14Z] ++ go env GOARCH INFO[2022-11-11T11:46:14Z] ++ echo amd64 INFO[2022-11-11T11:46:14Z] + GOARCH=amd64 INFO[2022-11-11T11:46:14Z] + KUBEFIRE_VERSION=v0.3.8 INFO[2022-11-11T11:46:14Z] + CONTAINERD_VERSION=v1.6.6 + IGNITE_VERION=v0.10.0 INFO[2022-11-11T11:46:14Z] + CNI_VERSION=v1.1.1 + RUNC_VERSION=v1.1.3 INFO[2022-11-11T11:46:14Z] + '[' -z v0.3.8 ']' + '[' -z v1.6.6 ']' + '[' -z v0.10.0 ']' + '[' -z v1.1.1 ']' + '[' -z v1.1.3 ']' INFO[2022-11-11T11:46:14Z] ++ sed -E 's/(v[0-9]+\.[0-9]+\.[0-9]+)[a-zA-Z0-9\-]*/\1/g' INFO[2022-11-11T11:46:14Z] +++ echo v0.3.8 INFO[2022-11-11T11:46:14Z] + STABLE_KUBEFIRE_VERSION=v0.3.8 INFO[2022-11-11T11:46:14Z] + rm -rf /tmp/kubefire INFO[2022-11-11T11:46:14Z] + mkdir -p /tmp/kubefire INFO[2022-11-11T11:46:14Z] + pushd /tmp/kubefire /tmp/kubefire /root INFO[2022-11-11T11:46:14Z] + trap cleanup EXIT ERR INT TERM INFO[2022-11-11T11:46:14Z] + check_virtualization + _is_arm_arch INFO[2022-11-11T11:46:14Z] + uname -m INFO[2022-11-11T11:46:14Z] + grep aarch64 INFO[2022-11-11T11:46:14Z] + return 1 INFO[2022-11-11T11:46:14Z] + lscpu INFO[2022-11-11T11:46:14Z] + grep 'Virtuali[s|z]ation' INFO[2022-11-11T11:46:14Z] Virtualization: VT-x Virtualization type: full INFO[2022-11-11T11:46:14Z] + lsmod INFO[2022-11-11T11:46:14Z] + grep kvm INFO[2022-11-11T11:46:14Z] kvm_intel 372736 0 kvm 1028096 1 kvm_intel INFO[2022-11-11T11:46:14Z] + install_runc + _check_version /usr/local/bin/runc -version v1.1.3 INFO[2022-11-11T11:46:14Z] + set +o pipefail + local exec_name=/usr/local/bin/runc + local exec_version_cmd=-version + local version=v1.1.3 + command -v /usr/local/bin/runc + return 1 + _is_arm_arch INFO[2022-11-11T11:46:14Z] + uname -m INFO[2022-11-11T11:46:14Z] + grep aarch64 INFO[2022-11-11T11:46:14Z] + return 1 INFO[2022-11-11T11:46:14Z] + curl -sfSL https://github.com/opencontainers/runc/releases/download/v1.1.3/runc.amd64 -o runc INFO[2022-11-11T11:46:14Z] + chmod +x runc INFO[2022-11-11T11:46:14Z] + sudo mv runc /usr/local/bin/ INFO[2022-11-11T11:46:14Z] + install_containerd + _check_version /usr/local/bin/containerd --version v1.6.6 INFO[2022-11-11T11:46:14Z] + set +o pipefail + local exec_name=/usr/local/bin/containerd + local exec_version_cmd=--version + local version=v1.6.6 + command -v /usr/local/bin/containerd + return 1 + local version=1.6.6 + local dir=containerd-1.6.6 + _is_arm_arch INFO[2022-11-11T11:46:14Z] + uname -m INFO[2022-11-11T11:46:14Z] + grep aarch64 INFO[2022-11-11T11:46:14Z] + return 1 INFO[2022-11-11T11:46:14Z] + curl -sfSLO https://github.com/containerd/containerd/releases/download/v1.6.6/containerd-1.6.6-linux-amd64.tar.gz INFO[2022-11-11T11:46:15Z] + mkdir -p containerd-1.6.6 INFO[2022-11-11T11:46:15Z] + tar -zxvf containerd-1.6.6-linux-amd64.tar.gz -C containerd-1.6.6 INFO[2022-11-11T11:46:15Z] bin/ bin/containerd-shim INFO[2022-11-11T11:46:15Z] bin/containerd INFO[2022-11-11T11:46:16Z] bin/containerd-shim-runc-v1 INFO[2022-11-11T11:46:16Z] bin/containerd-stress INFO[2022-11-11T11:46:16Z] bin/containerd-shim-runc-v2 INFO[2022-11-11T11:46:16Z] bin/ctr INFO[2022-11-11T11:46:17Z] + chmod +x containerd-1.6.6/bin/containerd containerd-1.6.6/bin/containerd-shim containerd-1.6.6/bin/containerd-shim-runc-v1 containerd-1.6.6/bin/containerd-shim-runc-v2 containerd-1.6.6/bin/containerd-stress containerd-1.6.6/bin/ctr INFO[2022-11-11T11:46:17Z] + sudo mv containerd-1.6.6/bin/containerd containerd-1.6.6/bin/containerd-shim containerd-1.6.6/bin/containerd-shim-runc-v1 containerd-1.6.6/bin/containerd-shim-runc-v2 containerd-1.6.6/bin/containerd-stress containerd-1.6.6/bin/ctr /usr/local/bin/ INFO[2022-11-11T11:46:17Z] + curl -sfSLO https://raw.githubusercontent.com/containerd/containerd/v1.6.6/containerd.service INFO[2022-11-11T11:46:17Z] + sudo groupadd containerd INFO[2022-11-11T11:46:17Z] + sudo mv containerd.service /etc/systemd/system/containerd.service INFO[2022-11-11T11:46:17Z] ++ command -v chgrp INFO[2022-11-11T11:46:17Z] ++ tr -d '\n' INFO[2022-11-11T11:46:17Z] + chgrp_path=/usr/bin/chgrp INFO[2022-11-11T11:46:17Z] + sudo sed -i -E 's#(ExecStart=/usr/local/bin/containerd)#\1\nExecStartPost=/usr/bin/chgrp containerd /run/containerd/containerd.sock#g' /etc/systemd/system/containerd.service INFO[2022-11-11T11:46:17Z] + sudo mkdir -p /etc/containerd INFO[2022-11-11T11:46:17Z] + containerd config default INFO[2022-11-11T11:46:17Z] + sudo tee /etc/containerd/config.toml INFO[2022-11-11T11:46:17Z] + sudo systemctl enable --now containerd INFO[2022-11-11T11:46:17Z] Created symlink /etc/systemd/system/multi-user.target.wants/containerd.service → /etc/systemd/system/containerd.service. INFO[2022-11-11T11:46:17Z] + install_cni + _check_version /opt/cni/bin/bridge --version v1.1.1 + set +o pipefail INFO[2022-11-11T11:46:17Z] + local exec_name=/opt/cni/bin/bridge + local exec_version_cmd=--version + local version=v1.1.1 + command -v /opt/cni/bin/bridge INFO[2022-11-11T11:46:17Z] + return 1 INFO[2022-11-11T11:46:17Z] + mkdir -p /opt/cni/bin INFO[2022-11-11T11:46:17Z] + local f=https://github.com/containernetworking/plugins/releases/download/v1.1.1/cni-plugins-linux-amd64-v1.1.1.tgz + _is_arm_arch INFO[2022-11-11T11:46:17Z] + uname -m INFO[2022-11-11T11:46:17Z] + grep aarch64 INFO[2022-11-11T11:46:17Z] + return 1 INFO[2022-11-11T11:46:17Z] + curl -sfSL https://github.com/containernetworking/plugins/releases/download/v1.1.1/cni-plugins-linux-amd64-v1.1.1.tgz INFO[2022-11-11T11:46:17Z] + tar -C /opt/cni/bin -xz INFO[2022-11-11T11:46:19Z] + install_cni_patches + _is_arm_arch INFO[2022-11-11T11:46:19Z] + uname -m INFO[2022-11-11T11:46:19Z] + grep aarch64 INFO[2022-11-11T11:46:19Z] + return 1 + curl -o host-local-rev -sfSL https://github.com/innobead/kubefire/releases/download/v0.3.8/host-local-rev-linux-amd64 INFO[2022-11-11T11:46:19Z] + chmod +x host-local-rev INFO[2022-11-11T11:46:19Z] + sudo mv host-local-rev /opt/cni/bin/ INFO[2022-11-11T11:46:19Z] + install_ignite + _check_version /usr/local/bin/ignite version v0.10.0 + set +o pipefail INFO[2022-11-11T11:46:19Z] + local exec_name=/usr/local/bin/ignite + local exec_version_cmd=version + local version=v0.10.0 + command -v /usr/local/bin/ignite + return 1 INFO[2022-11-11T11:46:19Z] + for binary in ignite ignited + echo 'Installing ignite...' INFO[2022-11-11T11:46:19Z] Installing ignite... INFO[2022-11-11T11:46:19Z] + local f=https://github.com/weaveworks/ignite/releases/download/v0.10.0/ignite-amd64 + _is_arm_arch INFO[2022-11-11T11:46:19Z] + uname -m INFO[2022-11-11T11:46:19Z] + grep aarch64 INFO[2022-11-11T11:46:19Z] + return 1 + curl -sfSLo ignite https://github.com/weaveworks/ignite/releases/download/v0.10.0/ignite-amd64 INFO[2022-11-11T11:46:20Z] + chmod +x ignite INFO[2022-11-11T11:46:20Z] + sudo mv ignite /usr/local/bin INFO[2022-11-11T11:46:20Z] + for binary in ignite ignited + echo 'Installing ignited...' Installing ignited... + local f=https://github.com/weaveworks/ignite/releases/download/v0.10.0/ignited-amd64 INFO[2022-11-11T11:46:20Z] + _is_arm_arch INFO[2022-11-11T11:46:20Z] + grep aarch64 + uname -m INFO[2022-11-11T11:46:20Z] + return 1 + curl -sfSLo ignited https://github.com/weaveworks/ignite/releases/download/v0.10.0/ignited-amd64 INFO[2022-11-11T11:46:21Z] + chmod +x ignited INFO[2022-11-11T11:46:21Z] + sudo mv ignited /usr/local/bin INFO[2022-11-11T11:46:21Z] + check_ignite + ignite version INFO[2022-11-11T11:46:21Z] Ignite version: version.Info{Major:"0", Minor:"10", GitVersion:"v0.10.0", GitCommit:"4540abeb9ba6daba32a72ef2b799095c71ebacb0", GitTreeState:"clean", BuildDate:"2021-07-19T20:52:59Z", GoVersion:"go1.16.3", Compiler:"gc", Platform:"linux/amd64", SandboxImage:version.Image{Name:"weaveworks/ignite", Tag:"v0.10.0", Delimeter:":"}, KernelImage:version.Image{Name:"weaveworks/ignite-kernel", Tag:"5.10.51", Delimeter:":"}} INFO[2022-11-11T11:46:21Z] Firecracker version: v0.22.4 INFO[2022-11-11T11:46:21Z] + create_cni_default_config INFO[2022-11-11T11:46:21Z] + mkdir -p /etc/cni/net.d/ INFO[2022-11-11T11:46:21Z] + sudo cat INFO[2022-11-11T11:46:21Z] + popd /root + cleanup INFO[2022-11-11T11:46:21Z] + rm -rf /tmp/kubefire

#! /usr/bin/bash # Update apt-get repository and install dependencies apt-get update && apt-get install -y --no-install-recommends dmsetup openssh-client git binutils # Install containerd if it's not present -- prevents breaking docker-ce installations which containerd || apt-get install -y --no-install-recommends containerd # Installing CNI # Current version from https://github.com/containernetworking/cni/releases export CNI_VERSION=v1.0.1 ARCH=$([ "$(uname -m)" = "x86_64" ] && echo amd64 || echo arm64) export ARCH sudo mkdir -p /opt/cni/bin curl -sSL "https://github.com/containernetworking/plugins/releases/download/${CNI_VERSION}/cni-plugins-linux-${ARCH}-${CNI_VERSION}.tgz" | sudo tar -xz -C /opt/cni/bin # Installing Ignite # Get the current version from https://github.com/weaveworks/ignite/releases export VERSION=v0.10.0 GOARCH=$(go env GOARCH 2>/dev/null || echo "amd64") export GOARCH for binary in ignite ignited; do echo "Installing ${binary}..." curl -sfLo ${binary} "https://github.com/weaveworks/ignite/releases/download/${VERSION}/${binary}-${GOARCH}" chmod +x ${binary} sudo mv ${binary} /usr/local/bin done # Check if the installation was successful ignite version

# wget https://github.com/kubernetes-sigs/cri-tools/releases/download/v1.21.0/crictl-v1.21.0-linux-amd64.tar.gz \ https://github.com/opencontainers/runc/releases/download/v1.0.0-rc93/runc.amd64 \ https://github.com/containernetworking/plugins/releases/download/v0.9.1/cni-plugins-linux-amd64-v0.9.1.tgz \ https://github.com/containerd/containerd/releases/download/v1.4.4/containerd-1.4.4-linux-amd64.tar.gz \ https://storage.googleapis.com/kubernetes-release/release/v1.21.0/bin/linux/amd64/kubectl \ https://storage.googleapis.com/kubernetes-release/release/v1.21.0/bin/linux/amd64/kube-proxy \ https://storage.googleapis.com/kubernetes-release/release/v1.21.0/bin/linux/amd64/kubelet

I’m not sure if there is a book on this topic specifically, but the book and RFC I referenced in my earlier post will help you better understand the fundamentals behind these protocols. You can see an example CNI plug-in here to learn about how CNIs are structured.

Also make sure that you have cri-o, crictl, containernetworking-plugins, and buildah or docker installed.

In my home lab, I don’t use (nor need) any of the fancy CNI plugins like calico, cilium or weavenet. I’m really happy with bridge, host-local and portmap from containernetworking/plugins with some static routes between the nodes. The only problem is that I can’t use NetworkPolicies.

The CNI is language-agnostic and there are many different plugins available.

Read more about the architecture of CRI-O here. The networking of the pod is set up through CNI, and CRI-O can be used with any CNI plugin.

In generic Kubernetes network policies, there is no action field. The Calico CNI plugin (Kubernetes network plugin that implements the Container Network Interface) provides this functionality, and in particular provides logging even for allowed traffic. And this worked when we tried it in our test clusters and in our own back end.

There is a CNI spec: https://github.com/containernetworking/cni/blob/main/SPEC.md which allows for custom network plugins. Thats how AWS/EKS nodes are able to assign VPC routable IPs to containers running on them.

um, they aren't missing anything (but see below). they are k8s.

so if you want to get the genuine original mainline experience you go to the project's github repo, they have releases, and mention that the detailed changelog has links to the binaries. yeey. (https://github.com/kubernetes/kubernetes/blob/master/CHANGEL... .. the client is the kubectl binary, the server has the control plane components the node binaries have the worker node stuff), you then have the option to set those up according to the documentation (generate TLS certs, specify the IP address range for pods (containers), install dependencies like etcd, and a CNI compatible container network layer provider -- if you have setup overlay networking eg. VXLAN or geneve or something fancy with openvswitch's OVN -- then the reference CNI plugin is probably sufficient)

at the end of this process you'll have the REST API (kube-apiserver) up and running and you can start submitting jobs (that will be persisted into etcd, eventually picked up by the scheduler control loop that calculates what should run where and persists it back to etcd, then a control loop on a particular worker will notice that something new is assigned to it, and it'll do the thing, allocate a pod, call CNI to allocate IP, etc.)

of course if you don't want to do all this by hand you can use a distribution that helps you with setup.

microk8s is a low-memory low-IO k8s distro by Canonical (Ubuntu folks) and they run dqlite (distributed sqlite) instead of etcd (to lower I/O and memory requirements), many people don't like it because it uses snaps

k3s is started by Rancher folks (and mostly still developed by them?),

there's k0s (for bare metal ... I have no idea what that means though), kind (kubernetes in docker), there's also k3d (k3s in docker)

these distributions work by consuming/wrapping the k8s components as go libraries - https://github.com/kubernetes/kubernetes/blob/master/staging...

...

then there's the whole zoo of various k8s plugins/addons/tools for networking (CNI - https://github.com/containernetworking/cni#3rd-party-plugins), storage (CSI - https://kubernetes-csi.github.io/docs/drivers.html), helm for package management, a ton of security-related things that try to spot errors in all this circus ... and so on.

#! /usr/bin/bash # Update apt-get repository and install dependencies apt-get update && apt-get install -y --no-install-recommends dmsetup openssh-client git binutils # Install containerd if it's not present -- prevents breaking docker-ce installations which containerd || apt-get install -y --no-install-recommends containerd # Installing CNI # Current version from https://github.com/containernetworking/cni/releases export CNI_VERSION=v1.0.1 ARCH=$([ "$(uname -m)" = "x86_64" ] && echo amd64 || echo arm64) export ARCH sudo mkdir -p /opt/cni/bin curl -sSL "https://github.com/containernetworking/plugins/releases/download/${CNI_VERSION}/cni-plugins-linux-${ARCH}-${CNI_VERSION}.tgz" | sudo tar -xz -C /opt/cni/bin # Installing Ignite # Get the current version from https://github.com/weaveworks/ignite/releases export VERSION=v0.10.0 GOARCH=$(go env GOARCH 2>/dev/null || echo "amd64") export GOARCH for binary in ignite ignited; do echo "Installing ${binary}..." curl -sfLo ${binary} "https://github.com/weaveworks/ignite/releases/download/${VERSION}/${binary}-${GOARCH}" chmod +x ${binary} sudo mv ${binary} /usr/local/bin done # Check if the installation was successful ignite version

The Container Network Interface (CNI) includes a specification for writing network plugins to configure network interfaces. This allows you to create overlay networks that satisfy Pod-to-Pod communication requirements.

In this lab you will bootstrap three Kubernetes worker nodes. The following components will be installed on each node: runc, container networking plugins, containerd, kubelet, and kube-proxy.

CNI type plugins follow the Container Network Interface spec and are used by the community to create advanced featured plugins. On the other hand, Kubenet utilizes bridge and host-local CNI plugins and has basic features.