change k8s pod cidr without reconstruct cluster

change_pod_cidr.sh

#!/bin/bash

POD_CIDR="100.64.0.0\/14"
CTL_MGR_CFG=/etc/kubernetes/manifests/kube-controller-manager.yaml 

kubectl apply -f  https://docs.projectcalico.org/v3.1/getting-started/kubernetes/installation/hosted/calicoctl.yaml

echo "Updating kube controller manager params..."
sed -i "s/--cluster-cidr=.*/--cluster-cidr=$POD_CIDR/g" $CTL_MGR_CFG

echo "Updating kubeadm configmap..."
kubectl get configmap kubeadm-config -o yaml -n kube-system | sed "s/        clusterCIDR: 192.168.0.0\/16/        clusterCIDR: $POD_CIDR/g" |  sed "s/      podSubnet: 192.168.0.0\/16/      podSubnet: $POD_CIDR/g" | kubectl apply -f -

echo "Updating kube-proxy configmap..."
kubectl get configmap kube-proxy -o yaml -n kube-system | sed "s/    clusterCIDR: 192.168.0.0\/16/    clusterCIDR: $POD_CIDR/g" | kubectl apply -f -

echo "Recreating kube-proxy pod..."
kubectl get pod -n kube-system | grep kube-proxy | awk '{print $1}' | xargs -r -L1 kubectl delete pod -n kube-system

echo "update calico config"
kubectl get daemonsets -n kube-system calico-node -o yaml | sed "s/value: 192.168.0.0\/16/value: $POD_CIDR/g" | kubectl apply -f -

echo "Recreating calico-node pod..."
kubectl get pod -n kube-system | grep calico-node | awk '{print $1}' | xargs -r -L1 kubectl delete pod -n kube-system

echo "Updating nodes..."
kubectl get nodes -o yaml | sed "/podCIDR: 192.168./d" > nodes.yaml
kubectl delete -f nodes.yaml
kubectl create -f nodes.yaml

echo "Updating calico data ..."
kubectl exec -ti -n kube-system calicoctl -- /calicoctl get ipPool default-ipv4-ippool -o yaml | sed "s/  cidr: 192.168.0.0\/16/  cidr: $POD_CIDR/g" > ippool.yaml
kubectl exec -ti -n kube-system calicoctl -- /calicoctl delete ipPool default-ipv4-ippool 
cat ippool.yaml | kubectl exec -ti -n kube-system calicoctl -- /calicoctl apply -f -

echo "Updating old pod..."
kubectl get pod --all-namespaces -o wide | grep "192.168" | awk '{print $2" -n "$1}' | xargs -r -L1 kubectl delete pod

kubectl get pod --all-namespaces -owide -w

救命的脚本