Kubernetes Networking

Overview

This article provides instructions in installing the networking layer to the Kubernetes clusters.

Calico Networking

You’ll need to install Calico which is the network layer for the cluster. There are two files you’ll retrieve from Tigera who makes Calico. The tigera-operator.yaml and custom-resources.yaml files.

In the custom-resources.yaml file, update the spec.calicoNetwork.ipPools.cidr line to point to the PodNetwork. In my case, 10.42.0.0/16.

In the tigera-operator.yaml file, update the image: line to point to the on-prem insecure registry and any imagePullPolicy lines to Always.

Once done, use kubectl to install the two configurations. First the tigera-operator.yaml file, then the custom-resources.yaml file.

kubectl create -f tigera-operator.yaml
kubectl create -f custom-resources.yaml

When done and all is working, you should also see several calico pods start up.

$ kubectl get pods -A | grep -E "(calico|tigera)"
calico-apiserver   calico-apiserver-6fd86fcb4b-77tld                         1/1     Running   0             32m
calico-apiserver   calico-apiserver-6fd86fcb4b-p6bzc                         1/1     Running   0             32m
calico-system      calico-kube-controllers-dd6c88556-zhg6b                   1/1     Running   0             45m
calico-system      calico-node-66fkb                                         1/1     Running   0             45m
calico-system      calico-node-99qs2                                         1/1     Running   0             45m
calico-system      calico-node-dtzgf                                         1/1     Running   0             45m
calico-system      calico-node-ksjpr                                         1/1     Running   0             45m
calico-system      calico-node-lhhrl                                         1/1     Running   0             45m
calico-system      calico-node-w8nmx                                         1/1     Running   0             45m
calico-system      calico-typha-69f9d4d5b4-vp7mp                             1/1     Running   0             44m
calico-system      calico-typha-69f9d4d5b4-xv5tg                             1/1     Running   0             45m
calico-system      calico-typha-69f9d4d5b4-z65kn                             1/1     Running   0             44m
calico-system      csi-node-driver-5czsp                                     2/2     Running   0             45m
calico-system      csi-node-driver-ch746                                     2/2     Running   0             45m
calico-system      csi-node-driver-gg9f4                                     2/2     Running   0             45m
calico-system      csi-node-driver-kwbwp                                     2/2     Running   0             45m
calico-system      csi-node-driver-nh564                                     2/2     Running   0             45m
calico-system      csi-node-driver-rvfd4                                     2/2     Running   0             45m
tigera-operator    tigera-operator-7d89d9444-4scfq                           1/1     Running   0             45m

It does take a bit so give it some time to get going.

Troubleshooting

I did have a problem with the installation the first time as I hadn’t updated the custom-resources.yaml file to update the cidr line with my podnetwork configuration. After rebuilding the cluster, I updated and reapplied and it worked. One other issue was crio wasn’t enabled or started on the first control node for some reason. Once it was enabled and started, it worked as expected.