Install CNI plugin
Kubernetes uses the Container Network Interface (CNI) to interact with networking providers like Calico. The Calico binary that presents this API to Kubernetes is called the CNI plugin and must be installed on every node in the Kubernetes cluster.
To understand how the Container Network Interface (CNI) works with Kubernetes, and how it enhances Kubernetes networking, read our Kubernetes CNI guide.
Provision Kubernetes user account for the plugin
The CNI plugin interacts with the Kubernetes API server while creating pods, both to obtain additional information and to update the datastore with information about the pod.
On the Kubernetes control plane node, create a key for the CNI plugin to authenticate with and certificate signing request.
openssl req -newkey rsa:4096 \
-keyout cni.key \
-nodes \
-out cni.csr \
-subj "/CN=calico-cni"
We will sign this certificate using the main Kubernetes CA.
sudo openssl x509 -req -in cni.csr \
-CA /etc/kubernetes/pki/ca.crt \
-CAkey /etc/kubernetes/pki/ca.key \
-CAcreateserial \
-out cni.crt \
-days 365
sudo chown $(id -u):$(id -g) cni.crt
Next, we create a kubeconfig file for the CNI plugin to use to access Kubernetes. Copy this cni.kubeconfig
file to every node in the cluster.
APISERVER=$(kubectl config view -o jsonpath='{.clusters[0].cluster.server}')
kubectl config set-cluster kubernetes \
--certificate-authority=/etc/kubernetes/pki/ca.crt \
--embed-certs=true \
--server=$APISERVER \
--kubeconfig=cni.kubeconfig
kubectl config set-credentials calico-cni \
--client-certificate=cni.crt \
--client-key=cni.key \
--embed-certs=true \
--kubeconfig=cni.kubeconfig
kubectl config set-context default \
--cluster=kubernetes \
--user=calico-cni \
--kubeconfig=cni.kubeconfig
kubectl config use-context default --kubeconfig=cni.kubeconfig
Provision RBAC
Define a cluster role the CNI plugin will use to access Kubernetes.
kubectl apply -f - <<EOF
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: calico-cni
rules:
# The CNI plugin needs to get pods, nodes, and namespaces.
- apiGroups: [""]
resources:
- pods
- nodes
- namespaces
verbs:
- get
# The CNI plugin patches pods/status.
- apiGroups: [""]
resources:
- pods/status
verbs:
- patch
# These permissions are required for Calico CNI to perform IPAM allocations.
- apiGroups: ["crd.projectcalico.org"]
resources:
- blockaffinities
- ipamblocks
- ipamhandles
verbs:
- get
- list
- create
- update
- delete
- apiGroups: ["crd.projectcalico.org"]
resources:
- ipamconfigs
- clusterinformations
- ippools
verbs:
- get
- list
EOF
Bind the cluster role to the calico-cni
account.
kubectl create clusterrolebinding calico-cni --clusterrole=calico-cni --user=calico-cni
Install the plugin
Do these steps on each node in your cluster.
Run these commands as root.
sudo su
Install the CNI plugin Binaries
curl -L -o /opt/cni/bin/calico https://github.com/projectcalico/cni-plugin/releases/download/v3.14.0/calico-amd64
chmod 755 /opt/cni/bin/calico
curl -L -o /opt/cni/bin/calico-ipam https://github.com/projectcalico/cni-plugin/releases/download/v3.14.0/calico-ipam-amd64
chmod 755 /opt/cni/bin/calico-ipam
Create the config directory
mkdir -p /etc/cni/net.d/
Copy the kubeconfig from the previous section
cp cni.kubeconfig /etc/cni/net.d/calico-kubeconfig
chmod 600 /etc/cni/net.d/calico-kubeconfig
Write the CNI configuration
cat > /etc/cni/net.d/10-calico.conflist <<EOF
{
"name": "k8s-pod-network",
"cniVersion": "0.3.1",
"plugins": [
{
"type": "calico",
"log_level": "info",
"datastore_type": "kubernetes",
"mtu": 1500,
"ipam": {
"type": "calico-ipam"
},
"policy": {
"type": "k8s"
},
"kubernetes": {
"kubeconfig": "/etc/cni/net.d/calico-kubeconfig"
}
},
{
"type": "portmap",
"snat": true,
"capabilities": {"portMappings": true}
}
]
}
EOF
Exit from su and go back to the logged in user.
exit
At this point Kubernetes nodes will become Ready
because Kubernetes has a networking provider and configuration installed.
kubectl get nodes