etcd-bkp-restore.md

ETCD back and restore process

Setup config for kind here.

kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
  - role: control-plane
    extraPortMappings:
    - containerPort: 80
      hostPort: 80
      listenAddress: "0.0.0.0"
      protocol: TCP
    - containerPort: 443
      hostPort: 443
      listenAddress: "0.0.0.0"
      protocol: TCP
    - containerPort: 2379
      hostPort: 2379
      listenAddress: "127.0.0.1"
      protocol: TCP
    kubeadmConfigPatches:
    - |
      kind: InitConfiguration
      nodeRegistration:
        kubeletExtraArgs:
          node-labels: "ingress-ready=true"
networking:
  kubeProxyMode: "ipvs"
  apiServerAddress: "${host_ip}"
  apiServerPort: 6443
containerdConfigPatches:
- |-
  [plugins."io.containerd.grpc.v1.cri".registry.mirrors."localhost:${reg_port}"]
    endpoint = ["http://${reg_name}:5000"]

Backup process

• Bellow script can perform a snapshot on host machine running kind container

#!/bin/bash
if [[ ! -d "ETCD" ]]
then
    mkdir ETCD
fi
NAME=$(kind get clusters)-control-plane
certfile="/etc/kubernetes/pki/etcd/server.crt"
cafile="/etc/kubernetes/pki/etcd/ca.crt"
keyfile="/etc/kubernetes/pki/etcd/server.key"
if [[ ! -f "ETCD/$certfile" ]]
then
docker cp $NAME:$certfile  ETCD/
fi
if [[ ! -f "ETCD/$cafile" ]]
then
docker cp $NAME:$cafile  ETCD/
fi
if [[ ! -f "ETCD/$keyfile" ]]
then
docker cp $NAME:$keyfile  ETCD/
fi
if [[ ! -f "/usr/bin/etcdctl" ]]
then    
        wget https://github.com/etcd-io/etcd/releases/download/v3.5.6/etcd-v3.5.6-linux-amd64.tar.gz
        tar -xvf etcd-v3.5.6-linux-amd64.tar.gz
        mv etcd-v3.5.6-linux-amd64/etcdctl /usr/local/bin/
fi      

ETCDCTL_API=3 etcdctl --endpoints https://127.0.0.1:2379 snapshot save kind.backup --cacert="ETCD/ca.crt" --cert="ETCD/server.crt" --key="ETCD/server.key"

Restore process

• Copy the binary and snpshot file inside the container

docker cp /usr/local/bin/etcdctl kind-control-plane:/
docker cp kind.backup kind-control-plane:/

• Login inside kind container

docker exec -it kind-control-plane bash

• Perform restore steps as bellow

mv /etc/kubernetes/manifests/etcd.yaml /
rm -rf /var/lib/etcd
ETCDCTL_API=3 /etcdctl --data-dir=/var/lib/etcd snapshot restore /kind.backup
mv /etcd.yaml /etc/kubernetes/manifests/etcd.yaml