renew etcd certificates for the master nodes in an ACK dedicated cluster - Container Service for Kubernetes

To ensure business continuity and security and mitigate potential risks caused by certificate leakage or key cracking, we recommend that you renew etcd certificates for the master nodes in a dedicated cluster when you receive system notifications. This topic describes how to renew etcd certificates for the master nodes in a Container Service for Kubernetes (ACK) dedicated cluster.

Background information

You can migrate workloads from an ACK dedicated cluster to an ACK Pro cluster. ACK can automatically manage the certificates of the etcd component and the Kubernetes control plane components in an ACK Pro cluster. You do not need to manually renew etcd certificates for ACK Pro clusters. For more information, see Hot migration from ACK dedicated clusters to ACK Pro clusters.

Usage notes

You are notified by internal message and text message two months before etcd certificates expire, and Renew Etcd Certificate is displayed on the Clusters page in the Container Service for Kubernetes (ACK) console.
During the renewal process, control plane components, such as the API server, etcd, kube-controller-manager, and kubelet, are restarted on master nodes one by one. Persistent connections to the API server are interrupted. We recommend that you renew etcd certificates during off-peak hours. The renewal process takes about 30 minutes.
If you have modified directory of the etcd certificates in an ACK dedicated cluster or the default configuration file directory of Kubernetes, you must create a soft link to the original directory before you renew the etcd certificates. Otherwise, the renewal fails.
If you manually renew etcd certificates, and Renew Etcd Certificate is still displayed in the console, submit a ticket to cancel the reminder.
If you fail to renew etcd certificates, submit a ticket.

Scenario 1: Renew etcd certificates that are about to expire

When etcd certificates in a cluster are about to expire, you can renew the certificates in the following ways:

Use the ACK console to renew etcd certificates
Manually renew etcd certificates

Use the ACK console to renew etcd certificates

Log on to the ACK console. In the left-side navigation pane, click Clusters.
Click Renew Etcd Certificate to the right of the cluster whose etcd certificates are about to expire. In the Update Certificate message, click Update Certificate.
Note
If the etcd certificates of a cluster are about to expire after two months, Renew Etcd Certificate is displayed on the right side of the cluster.
In the Note message, click OK.
After the certificates are renewed:
- The certificate has been updated is displayed in the Update Certificate message.
- On the Clusters page, Renew Etcd Certificate on the right side of the cluster disappears.

Manually renew etcd certificates

Scenarios

The etcd certificates in an ACK dedicated cluster are about to expire.
The etcd certificates cannot be renewed by deploying a new template.
The etcd certificates cannot be renewed in the ACK console.

In the preceding scenarios, you can log on to a master node in the ACK dedicated cluster and perform the following steps to renew the etcd certificates:

Note

The script in the following section must be run by using the root user.

Make sure that password-free logon between master nodes is configured for the root user.
Use SSH to log on to a master node from another master node. If the system prompts you to enter a password, perform the following steps to configure password-free logon between master nodes:
```
# 1. Generate a key. Skip this step if a key exists on your node. 
ssh-keygen -t rsa

# 2. Use ssh-copy-id to copy the public key to all other master nodes. Replace $(internal-ip) with the private IP address of each master node. 
ssh-copy-id -i ~/.ssh/id_rsa.pub $(internal-ip)
```
Note
If you do not configure password-free logon between master nodes, the system prompts you to enter the password of the root user when you run the script.

Use the following template to create a file named restart-apiserver.sh and a file named rotate-etcd.sh, and save the files in the same directory.

Note

The rotate-etcd.sh script obtains region information by accessing the metadata service of the node, and it pulls renewed images from the region. You can also specify the region information by entering the --region xxxx parameter when executing the script.

Example of the restart-apiserver.sh script

#! /bin/bash

declare -x cmd

k8s::wait_apiserver_ready() {
  set -e
  for i in $(seq 600); do
    if kubectl cluster-info &>/dev/null; then
      return 0
    else
      echo "wait apiserver to be ready, retry ${i}th after 1s"
      sleep 1
    fi
  done
  echo "failed to wait apiserver to be ready"
  return 1
}

function check_container_runtime() {
  if command -v dockerd &>/dev/null && ps aux | grep -q "[d]ockerd"; then
    cmd=docker
  elif command -v containerd &>/dev/null && ps aux | grep -q "[c]ontainerd"; then
    cmd=crictl
  else
    echo "Neither Dockerd nor Containerd is installed or running."
    exit 1
  fi
}

function restart_apiserver() {
  # Identify the container runtime.
  if [[ $cmd == "docker" ]]; then
    # Run the docker command to restart the pod that runs kube-apiserver.
    container_id=$(docker ps | grep kube-apiserver | awk '{print $1}' | head -n 1 )
    if [[ -n $container_id ]]; then
      echo "Restarting kube-apiserver pod using Docker: $container_id"
      docker restart "${container_id}"
    else
      echo "kube-apiserver pod not found."
    fi
  elif [[ $cmd == "crictl" ]]; then
    # Run the crictl command to restart the pod that runs kube-apiserver.
    pod_id=$(crictl pods --label component=kube-apiserver --latest --state=ready | grep -v "POD ID" | head -n 1 | awk '{print $1}')
    if [[ -n $pod_id ]]; then
      echo "Restarting kube-apiserver pod using crictl: $pod_id"
      crictl stopp "${pod_id}"
    else
      echo "kube-apiserver pod not found."
    fi
  else
    echo "Unsupported container runtime: $cmd"
  fi
  k8s::wait_apiserver_ready
}

check_container_runtime
restart_apiserver
echo "API Server restarted"

Example of the rotate-etcd.sh script

#!/bin/bash

set -eo pipefail

declare -x TARGET_TEAR
declare -x cmd
dir=/tmp/etcdcert
KUBE_CERT_PATH=/etc/kubernetes/pki
ETCD_CERT_DIR=/var/lib/etcd/cert
ETCD_HOSTS=""
currentDir="$PWD"

# Renew the cluster certificates. Replace cn-hangzhou in the following content with the region ID of your cluster. 
function get_etcdhosts() {
  name1=$(find "$ETCD_CERT_DIR" -name '*-name-1.pem' -exec basename {} \; | sed 's/-name-1.pem//g')
  name2=$(find "$ETCD_CERT_DIR" -name '*-name-2.pem' -exec basename {} \; | sed 's/-name-2.pem//g')
  name3=$(find "$ETCD_CERT_DIR" -name '*-name-3.pem' -exec basename {} \; | sed 's/-name-3.pem//g')

  echo "hosts: $name1 $name2 $name3"
  ETCD_HOSTS="$name1 $name2 $name3"
}

function gencerts() {
  echo "generate ssl cert ..."
  rm -rf $dir
  mkdir -p "$dir"

  local hosts
  hosts=$(echo $ETCD_HOSTS | tr -s " " ",")

  echo "-----generate ca"
  echo '{"CN":"CA","key":{"algo":"rsa","size":2048}, "ca": {"expiry": "438000h"}}' |
    cfssl gencert -initca - | cfssljson -bare $dir/ca -
  echo '{"signing":{"default":{"expiry":"438000h","usages":["signing","key encipherment","server auth","client auth"]}}}' >$dir/ca-config.json

  echo "-----generate etcdserver"
  export ADDRESS=$hosts,ext1.example.com,coreos1.local,coreos1,127.0.0.1
  export NAME=etcd-server
  echo '{"CN":"'$NAME'","hosts":[""],"key":{"algo":"rsa","size":2048}}' |
    cfssl gencert -config=$dir/ca-config.json -ca=$dir/ca.pem -ca-key=$dir/ca-key.pem -hostname="$ADDRESS" - | cfssljson -bare $dir/$NAME
  export ADDRESS=
  export NAME=etcd-client
  echo '{"CN":"'$NAME'","hosts":[""],"key":{"algo":"rsa","size":2048}}' |
    cfssl gencert -config=$dir/ca-config.json -ca=$dir/ca.pem -ca-key=$dir/ca-key.pem -hostname="$ADDRESS" - | cfssljson -bare $dir/$NAME

  # gen peer-ca
  echo "-----generate peer certificates"
  echo '{"CN":"Peer-CA","key":{"algo":"rsa","size":2048}, "ca": {"expiry": "438000h"}}' | cfssl gencert -initca - | cfssljson -bare $dir/peer-ca -
  echo '{"signing":{"default":{"expiry":"438000h","usages":["signing","key encipherment","server auth","client auth"]}}}' >$dir/peer-ca-config.json
  i=0
  for host in $ETCD_HOSTS; do
    ((i = i + 1))
    export MEMBER=${host}-name-$i
    echo '{"CN":"'${MEMBER}'","hosts":[""],"key":{"algo":"rsa","size":2048}}' |
      cfssl gencert -ca=$dir/peer-ca.pem -ca-key=$dir/peer-ca-key.pem -config=$dir/peer-ca-config.json -profile=peer \
        -hostname="$hosts,${MEMBER}.local,${MEMBER}" - | cfssljson -bare $dir/${MEMBER}
  done

  # Create a CA bundle.
  cat $KUBE_CERT_PATH/etcd/ca.pem >>$dir/bundle_ca.pem
  cat $ETCD_CERT_DIR/ca.pem >>$dir/bundle_ca.pem
  cat $dir/ca.pem >>$dir/bundle_ca.pem

  # Create a peer CA bundle.
  cat $ETCD_CERT_DIR/peer-ca.pem >$dir/bundle_peer-ca.pem
  cat $dir/peer-ca.pem >>$dir/bundle_peer-ca.pem

  current_year=$(date +%Y)
  TARGET_TEAR=$((TARGET_TEAR + 50))

  # chown
  chown -R etcd:etcd $dir
  chmod 0644 $dir/*
}

function etcd_client_urls() {
  local etcd_hosts=()
  for ip in "${ETCD_HOSTS[@]}"; do
    etcd_hosts+=("https://$ip:2379")
  done
  local result=$(
    IFS=','
    echo "${etcd_hosts[*]}"
  )
  echo "$result"
}

function check_cert_files_exist() {
  REQUIRED_CERTS=("ca.pem" "etcd-server-key.pem" "etcd-server.pem" "peer-ca-key.pem" "peer-ca.pem")
  if [ ! -d "$ETCD_CERT_DIR" ]; then
    echo "Error: Directory $ETCD_CERT_DIR does not exist"
    exit 1
  fi

  for cert_file in "${REQUIRED_CERTS[@]}"; do
    if [ ! -f "$ETCD_CERT_DIR/$cert_file" ]; then
      echo "Error: File $ETCD_CERT_DIR/$cert_file does not exist"
      exit 1
    fi
  done

  echo "All required certificate files exist"
}

function check_etcd_cluster_ready() {
  local etcd_endpoints=()
  for ip in $ETCD_HOSTS; do
    etcd_endpoints+=("https://$ip:2379")
  done
  ready=0
  for i in $(seq 300); do
    for idx in "${!etcd_endpoints[@]}"; do
      endpoint="${etcd_endpoints[$idx]}"
      local health_output=$(ETCDCTL_API=3 etcdctl --cacert=/var/lib/etcd/cert/ca.pem --cert=/var/lib/etcd/cert/etcd-server.pem --key=/var/lib/etcd/cert/etcd-server-key.pem --endpoints "$endpoint" endpoint health --command-timeout=1s 2>&1)
      if echo "$health_output" | grep -q "successfully committed proposal"; then
          unset 'etcd_endpoints[$idx]'
      else
          echo "etcdctl result: ${health_output}"
          echo "$endpoint is not ready"
      fi
    done
    # shellcheck disable=SC2199
    if [[ -z "${etcd_endpoints[@]}" ]]; then
      echo "ETCD cluster is ready"
      ready=1
      break
    fi
    printf "wait etcd cluster to be ready, retry %d after 1s,total 300s \n" "$i"
  done
}

function check_container_runtime() {
  if command -v dockerd &>/dev/null && ps aux | grep -q "[d]ockerd"; then
    cmd=docker
  elif command -v containerd &>/dev/null && ps aux | grep -q "[c]ontainerd"; then
    cmd=crictl
  else
    echo "Neither Dockerd nor Containerd is installed or running."
    exit 1
  fi
}

function rotate_etcd_ca() {
  for ADDR in $ETCD_HOSTS; do
    echo "update etcd CA on node $ADDR"
    scp -o StrictHostKeyChecking=no $dir/bundle_ca.pem root@$ADDR:$ETCD_CERT_DIR/ca.pem
    scp -o StrictHostKeyChecking=no $dir/bundle_ca.pem root@$ADDR:$KUBE_CERT_PATH/etcd/ca.pem
    scp -o StrictHostKeyChecking=no $dir/etcd-client.pem root@$ADDR:$KUBE_CERT_PATH/etcd/etcd-client.pem
    scp -o StrictHostKeyChecking=no $dir/etcd-client-key.pem root@$ADDR:$KUBE_CERT_PATH/etcd/etcd-client-key.pem
    scp -o StrictHostKeyChecking=no $dir/bundle_peer-ca.pem root@$ADDR:$ETCD_CERT_DIR/peer-ca.pem

    ssh -o StrictHostKeyChecking=no root@$ADDR chown -R etcd:etcd $ETCD_CERT_DIR
    ssh -o StrictHostKeyChecking=no root@$ADDR chmod 0644 $ETCD_CERT_DIR/*
    echo "restart etcd on node $ADDR"
    ssh -o StrictHostKeyChecking=no root@$ADDR systemctl restart etcd
    echo "etcd on node $ADDR restarted"

    # Check whether the etcd is started and whether the cluster runs as normal.
    echo "check connectivity for etcd nodes"
    check_etcd_cluster_ready
    echo "end to check connectivity for etcd nodes"
    restart_one_apiserver $ADDR
    echo "apiserver on node $ADDR restarted"
  done
}

function rotate_etcd_certs() {
  for ADDR in $ETCD_HOSTS; do
    echo "update etcd peer certs on node $ADDR"
    scp -o StrictHostKeyChecking=no \
      $dir/{peer-ca-key.pem,etcd-server.pem,etcd-server-key.pem,etcd-client.pem,etcd-client-key.pem,ca-key.pem,*-name*.pem} root@$ADDR:$ETCD_CERT_DIR/

    ssh -o StrictHostKeyChecking=no root@$ADDR chown -R etcd:etcd $ETCD_CERT_DIR

    ssh -o StrictHostKeyChecking=no root@$ADDR \
      chmod 0400 $ETCD_CERT_DIR/{peer-ca-key.pem,etcd-server.pem,etcd-server-key.pem,etcd-client.pem,etcd-client-key.pem,ca-key.pem,*-name*.pem}

    echo "restart etcd on node $ADDR"
    ssh -o StrictHostKeyChecking=no root@$ADDR systemctl restart etcd
    echo "etcd on node $ADDR restarted"
    echo "check connectivity for etcd nodes"
    check_etcd_cluster_ready
    echo "end to check connectivity for etcd nodes"
  done
}

function recover_etcd_ca() {
  # Update certs on etcd nodes.
  for ADDR in $ETCD_HOSTS; do
    echo "replace etcd CA on node $ADDR"
    scp -o StrictHostKeyChecking=no $dir/ca.pem root@$ADDR:$ETCD_CERT_DIR/ca.pem
    scp -o StrictHostKeyChecking=no $dir/ca.pem root@$ADDR:$KUBE_CERT_PATH/etcd/ca.pem
    scp -o StrictHostKeyChecking=no $dir/ca.pem root@$ADDR:$KUBE_CERT_PATH/etcd/ca.pem
    scp -o StrictHostKeyChecking=no $dir/peer-ca.pem root@$ADDR:$ETCD_CERT_DIR/peer-ca.pem
    ssh -o StrictHostKeyChecking=no root@$ADDR chown -R etcd:etcd $ETCD_CERT_DIR
    echo "restart apiserver on node $ADDR"
    restart_one_apiserver $ADDR
    echo "apiserver on node $ADDR restarted"
    echo "restart etcd on node $ADDR"
    ssh -o StrictHostKeyChecking=no root@$ADDR systemctl restart etcd
    echo "etcd on node $ADDR restarted"
    echo "check connectivity for etcd nodes"
    check_etcd_cluster_ready
    echo "end to check connectivity for etcd nodes"
    sleep 5
  done
}

function recover_etcd_client_ca() {
  # Update certs on etcd nodes.
  for ADDR in $ETCD_HOSTS; do
    echo "replace etcd CA on node $ADDR"
    scp -o StrictHostKeyChecking=no $dir/ca.pem root@$ADDR:$KUBE_CERT_PATH/etcd/ca.pem
    scp -o StrictHostKeyChecking=no $dir/ca.pem root@$ADDR:$KUBE_CERT_PATH/etcd/ca.pem
  done
}

function renew_k8s_certs() {
  # try to get region id from meta-server if not given in parameter
  META_REGION=$(get_region_id)
  if [[ -z "$REGION" ]]; then
    if [[ -z "$META_REGION" ]]; then
        echo "failed to get region id from ECS meta-server, please enter the region parameter."
        return 1
    fi
    REGION=$META_REGION
  elif [[ -n "${META_REGION}" && "$REGION" != "$META_REGION" ]] ; then
    echo "switch to use local region id $META_REGION"
    REGION=$META_REGION
  fi
  # Update certs for k8s components and kubeconfig
  for ADDR in $ETCD_HOSTS; do
    echo "renew k8s components cert on node $ADDR"
    #compatible containerd
    set +e
    IMAGE="registry.$REGION.aliyuncs.com/acs/etcd-rotate:v2.0.0"
    if is_vpc; then
      IMAGE="registry-vpc.$REGION.aliyuncs.com/acs/etcd-rotate:v2.0.0"
    fi
    echo "will pull rotate image $IMAGE"
    ssh -o StrictHostKeyChecking=no root@$ADDR docker run --privileged=true  -v /:/alicoud-k8s-host --pid host --net host \
             $IMAGE /renew/upgrade-k8s.sh --role master
    ssh -o StrictHostKeyChecking=no root@$ADDR ctr image pull $IMAGE
    ssh -o StrictHostKeyChecking=no root@$ADDR ctr run --privileged=true --mount type=bind,src=/,dst=/alicoud-k8s-host,options=rbind:rw \
            --net-host $IMAGE cert-rotate /renew/upgrade-k8s.sh --role master
    set -e
    echo "finished renew k8s components cert on $ADDR"
  done
}

function get_region_id() {
    set +e; # close error out
    local path=100.100.100.200/latest/meta-data/region-id
    for (( i=0; i<3; i++));
    do
        response=$(curl --retry 1 --retry-delay 5 -sSL $path)
        if [[ $? -gt 0 || "x$response" == "x" ]];
        then
            sleep 2; continue
        fi
        if echo "$response"|grep -E "<title>.*</title>" >/dev/null;
        then
            sleep 3; continue
        fi
        echo "$response"
        # return from metadata succeed.
        set -e; return
    done
    set -e # open error out
    # function will return empty string when failed
}

function is_vpc() {
    # Execute the curl command and capture the network-type from ECS meta-server
    response=$(curl -s http://100.100.100.200/latest/meta-data/network-type)
    if [ "$response" = "vpc" ]; then
      return 0
    else
      return 1
    fi
}

function generate_cm() {
  echo "generate status configmap"

  cat <<-"EOF" >/tmp/ack-rotate-etcd-ca-cm.yaml.tpl
apiVersion: v1
kind: ConfigMap
metadata:
  name: ack-rotate-etcd-status
  namespace: kube-system
data:
  status: "success"
  hosts: "$hosts"
EOF

  sed -e "s#\$hosts#$ETCD_HOSTS#" /tmp/ack-rotate-etcd-ca-cm.yaml.tpl | kubectl apply -f -
}

function restart_one_apiserver() {
  ADDR=$1
  if [[ -z "${ADDR}" ]]; then
    printf "ADDR is empty,exit."
    exit 1
  fi
  printf "restart apiserver on node %s\n" "${ADDR}"
  scp -o StrictHostKeyChecking=no "${currentDir}"/restart-apiserver.sh root@"${ADDR}":/tmp/restart-apiserver.sh
  ssh -e none -o StrictHostKeyChecking=no root@"${ADDR}" chmod +x /tmp/restart-apiserver.sh
  ssh -e none -o StrictHostKeyChecking=no root@"${ADDR}" bash /tmp/restart-apiserver.sh
}

while
    [[ $# -gt 0 ]]
do
    key="$1"

    case $key in
    --region)
      export REGION=$2
      shift
      ;;
    *)
      echo "unknown option [$key]"
      exit 1
      ;;
    esac
    shift
done

get_etcdhosts
echo "${ETCD_HOSTS[@]}"

check_container_runtime

# Update certs on etcd nodes.
echo "---restart runtime and kubelet on master nodes---"
for ADDR in $ETCD_HOSTS; do
  if [ "$cmd" == "docker" ]; then
    echo "restart docker on node $ADDR"
    ssh -o StrictHostKeyChecking=no root@$ADDR systemctl restart docker
  fi
  ssh -e none -o StrictHostKeyChecking=no root@"${ADDR}" systemctl restart kubelet
done
sleep 5
echo "---end to restart runtime and kubelet on master nodes---"

echo "---renew k8s components certs---"
renew_k8s_certs
echo "---end to renew k8s components certs---"

echo "---check cert files exist---"
check_cert_files_exist
echo "---end to check cert files exist---"

echo "---check connectivity for etcd nodes---"
check_etcd_cluster_ready
echo "---end to check connectivity for etcd nodes---"

# Update certs on etcd nodes.
for ADDR in $ETCD_HOSTS; do
  scp -o StrictHostKeyChecking=no restart-apiserver.sh root@$ADDR:/tmp/restart-apiserver.sh
  ssh -o StrictHostKeyChecking=no root@$ADDR chmod +x /tmp/restart-apiserver.sh
done

gencerts

echo "---rotate etcd ca and etcd client ca---"
rotate_etcd_ca
echo "---end to rotate etcd ca and etcd client ca---"

echo "---rotate etcd peer and certs---"
rotate_etcd_certs
echo "---end to rotate etcd peer and certs---"

echo "check etcd cluster ready"
check_etcd_cluster_ready

echo "---replace etcd ca---"
recover_etcd_ca
echo "---end to replace etcd ca---"

generate_cm
echo "etcd CA and certs have succesfully rotated!"

Run the bash rotate-etcd.sh command on a master node.
If etcd CA and certs have succesfully rotated! is returned, the etcd certificates and cluster certificates on all master nodes of the cluster are renewed.

Check whether the etcd certificates are renewed.

cd /var/lib/etcd/cert
for i in `ls | grep pem| grep -v key`;do openssl x509 -noout -text -in $i | grep -i after && echo "$i" ;done


cd /etc/kubernetes/pki/etcd
for i in `ls | grep pem| grep -v key`;do openssl x509 -noout -text -in $i | grep -i after && echo "$i" ;done


cd /etc/kubernetes/pki/
for i in `ls | grep crt| grep -v key`;do openssl x509 -noout -text -in $i | grep -i after && echo "$i" ;done

Note

If the expiration time displayed in the preceding script output is 50 years later, the renewal is completed.

Scenario 2: Renew expired etcd certificates

Scenarios

The etcd certificates are expired.
Renew etcd certificates when you cannot access the API server of your cluster.
The etcd certificates cannot be renewed by deploying a new template.
The etcd certificates cannot be renewed in the ACK console.

In the preceding scenarios, you can log on to a master node in the ACK dedicated cluster and perform the following steps to renew the etcd certificates:

Note

The script in the following section must be run by using the root user.

Make sure that password-free logon between master nodes is configured for the root user.
Use SSH to log on to a master node from another master node. If the system prompts you to enter a password, perform the following steps to configure password-free logon between master nodes:
```
# 1. Generate a key. Skip this step if a key exists on your node. 
ssh-keygen -t rsa

# 2. Use ssh-copy-id to copy the public key to all other master nodes. Replace $(internal-ip) with the private IP address of each master node. 
ssh-copy-id -i ~/.ssh/id_rsa.pub $(internal-ip)
```
Note
If you do not configure password-free logon between master nodes, the system prompts you to enter the password of the root user when you run the script.

Use the following template to create a file named restart-apiserver.sh and a file named rotate-etcd.sh, and save the files in the same directory.

Note

Example of the restart-apiserver.sh script

#! /bin/bash

declare -x cmd

k8s::wait_apiserver_ready() {
  set -e
  for i in $(seq 600); do
    if kubectl cluster-info &>/dev/null; then
      return 0
    else
      echo "wait apiserver to be ready, retry ${i}th after 1s"
      sleep 1
    fi
  done
  echo "failed to wait apiserver to be ready"
  return 1
}

function check_container_runtime() {
  if command -v dockerd &>/dev/null && ps aux | grep -q "[d]ockerd"; then
    cmd=docker
  elif command -v containerd &>/dev/null && ps aux | grep -q "[c]ontainerd"; then
    cmd=crictl
  else
    echo "Neither Dockerd nor Containerd is installed or running."
    exit 1
  fi
}

function restart_apiserver() {
  # Identify the container runtime.
  if [[ $cmd == "docker" ]]; then
    # Run the docker command to restart the pod that runs kube-apiserver.
    container_id=$(docker ps | grep kube-apiserver | awk '{print $1}' | head -n 1 )
    if [[ -n $container_id ]]; then
      echo "Restarting kube-apiserver pod using Docker: $container_id"
      docker restart "${container_id}"
    else
      echo "kube-apiserver pod not found."
    fi
  elif [[ $cmd == "crictl" ]]; then
    # Run the crictl command to restart the pod that runs kube-apiserver.
    pod_id=$(crictl pods --label component=kube-apiserver --latest --state=ready | grep -v "POD ID" | head -n 1 | awk '{print $1}')
    if [[ -n $pod_id ]]; then
      echo "Restarting kube-apiserver pod using crictl: $pod_id"
      crictl stopp "${pod_id}"
    else
      echo "kube-apiserver pod not found."
    fi
  else
    echo "Unsupported container runtime: $cmd"
  fi
  k8s::wait_apiserver_ready
}

check_container_runtime
restart_apiserver
echo "API Server restarted"

Example of the rotate-etcd.sh script

#!/bin/bash

set -eo pipefail

declare -x TARGET_TEAR
declare -x cmd
dir=/tmp/rollback/etcdcert
KUBE_CERT_PATH=/etc/kubernetes/pki
ETCD_CERT_DIR=/var/lib/etcd/cert
ETCD_HOSTS=""
currentDir="$PWD"

# Renew the cluster certificates. Replace cn-hangzhou in the following content with the region ID of your cluster. 
function get_etcdhosts() {
  name1=$(find "$ETCD_CERT_DIR" -name '*-name-1.pem' -exec basename {} \; | sed 's/-name-1.pem//g')
  name2=$(find "$ETCD_CERT_DIR" -name '*-name-2.pem' -exec basename {} \; | sed 's/-name-2.pem//g')
  name3=$(find "$ETCD_CERT_DIR" -name '*-name-3.pem' -exec basename {} \; | sed 's/-name-3.pem//g')

  echo "hosts: $name1 $name2 $name3"
  ETCD_HOSTS="$name1 $name2 $name3"
}

function gencerts() {
  echo "generate ssl cert ..."
  rm -rf $dir
  mkdir -p "$dir"
  cd $dir

  local hosts
  hosts=$(echo $ETCD_HOSTS | tr -s " " ",")

  echo "generate ca"
  echo '{"CN":"CA","key":{"algo":"rsa","size":2048}, "ca": {"expiry": "438000h"}}' |
    cfssl gencert -initca - | cfssljson -bare $dir/ca -
  echo '{"signing":{"default":{"expiry":"438000h","usages":["signing","key encipherment","server auth","client auth"]}}}' >$dir/ca-config.json

  echo "generate etcd server certificates"
  export ADDRESS=$hosts,ext1.example.com,coreos1.local,coreos1,127.0.0.1
  export NAME=etcd-server
  echo '{"CN":"'$NAME'","hosts":[""],"key":{"algo":"rsa","size":2048}}' |
    cfssl gencert -config=$dir/ca-config.json -ca=$dir/ca.pem -ca-key=$dir/ca-key.pem -hostname="$ADDRESS" - | cfssljson -bare $dir/$NAME
  export ADDRESS=
  export NAME=etcd-client
  echo '{"CN":"'$NAME'","hosts":[""],"key":{"algo":"rsa","size":2048}}' |
    cfssl gencert -config=$dir/ca-config.json -ca=$dir/ca.pem -ca-key=$dir/ca-key.pem -hostname="$ADDRESS" - | cfssljson -bare $dir/$NAME

  # gen peer-ca
  echo "generate peer certificates"
  echo '{"CN":"Peer-CA","key":{"algo":"rsa","size":2048}, "ca": {"expiry": "438000h"}}' | cfssl gencert -initca - | cfssljson -bare $dir/peer-ca -
  echo '{"signing":{"default":{"expiry":"438000h","usages":["signing","key encipherment","server auth","client auth"]}}}' >$dir/peer-ca-config.json
  i=0
  for host in $ETCD_HOSTS; do
    ((i = i + 1))
    export MEMBER=${host}-name-$i
    echo '{"CN":"'${MEMBER}'","hosts":[""],"key":{"algo":"rsa","size":2048}}' |
      cfssl gencert -ca=$dir/peer-ca.pem -ca-key=$dir/peer-ca-key.pem -config=$dir/peer-ca-config.json -profile=peer \
        -hostname="$hosts,${MEMBER}.local,${MEMBER}" - | cfssljson -bare $dir/${MEMBER}
  done

  # chown
  chown -R etcd:etcd $dir
  chmod 0644 $dir/*

  for ADDR in $ETCD_HOSTS; do
    printf "sync the certificates of node %s" "${ADDR}"
    ssh -e none -o StrictHostKeyChecking=no root@"${ADDR}" mkdir -p "${dir}"
    scp -o StrictHostKeyChecking=no "${dir}"/* root@"${ADDR}":/var/lib/etcd/cert/
    scp -o StrictHostKeyChecking=no "${dir}"/ca.pem "${dir}"/etcd-client.pem "${dir}"/etcd-client-key.pem root@"${ADDR}":/etc/kubernetes/pki/etcd/
  done
}

function generate_cm() {
  echo "generate status configmap"

  cat <<-"EOF" >/tmp/ack-rotate-etcd-ca-cm.yaml.tpl
apiVersion: v1
kind: ConfigMap
metadata:
  name: ack-rotate-etcd-status
  namespace: kube-system
data:
  status: "success"
  hosts: "$hosts"
EOF

  sed -e "s#\$hosts#$ETCD_HOSTS#" /tmp/ack-rotate-etcd-ca-cm.yaml.tpl | kubectl apply -f -
}

function rotate_etcd() {
  for ADDR in $ETCD_HOSTS; do
    printf "rotate etcd's certificates on node %s\n" "${ADDR}"
      if [ "$cmd" == "docker" ]; then
        echo "restart docker on node $ADDR"
        ssh -e none -o StrictHostKeyChecking=no root@$ADDR systemctl restart docker
      fi
    ssh -e none -o StrictHostKeyChecking=no root@$ADDR systemctl restart etcd
  done
}

function rotate_apiserver() {
  echo "current dir: $currentDir"
  for ADDR in $ETCD_HOSTS; do
    printf "restart apiserver on node %s\n" "${ADDR}"
    scp -o StrictHostKeyChecking=no "${currentDir}"/restart-apiserver.sh root@"${ADDR}":/tmp/restart-apiserver.sh
    ssh -e none -o StrictHostKeyChecking=no root@"${ADDR}" systemctl restart kubelet
    ssh -e none -o StrictHostKeyChecking=no root@"${ADDR}" chmod +x /tmp/restart-apiserver.sh
    ssh -e none -o StrictHostKeyChecking=no root@"${ADDR}" bash /tmp/restart-apiserver.sh
  done
}

function check_etcd_cluster_ready() {
  local etcd_endpoints=()
  for ip in $ETCD_HOSTS; do
    etcd_endpoints+=("https://$ip:2379")
  done

  for i in $(seq 300); do
    for idx in "${!etcd_endpoints[@]}"; do
      endpoint="${etcd_endpoints[$idx]}"
      local health_output=$(ETCDCTL_API=3 etcdctl --cacert=/var/lib/etcd/cert/ca.pem --cert=/var/lib/etcd/cert/etcd-server.pem --key=/var/lib/etcd/cert/etcd-server-key.pem --endpoints "$endpoint" endpoint health --command-timeout=1s 2>&1)
      if echo "$health_output" | grep -q "successfully committed proposal"; then
          unset 'etcd_endpoints[$idx]'
      else
          echo "etcdctl result: ${health_output}"
          echo "$endpoint is not ready"
      fi
    done
    # shellcheck disable=SC2199
    if [[ -z "${etcd_endpoints[@]}" ]]; then
      echo "ETCD cluster is ready"
      break
    fi
    sleep 1
    printf "wait etcd cluster to be ready, retry %d after 1s,total 300s \n" "$i"
  done
}

function get_region_id() {
    set +e; # close error out
    local path=100.100.100.200/latest/meta-data/region-id
    for (( i=0; i<3; i++));
    do
        response=$(curl --retry 1 --retry-delay 5 -sSL $path)
        if [[ $? -gt 0 || "x$response" == "x" ]];
        then
            sleep 2; continue
        fi
        if echo "$response"|grep -E "<title>.*</title>" >/dev/null;
        then
            sleep 3; continue
        fi
        echo "$response"
        # return from metadata succeed.
        set -e; return
    done
    set -e # open error out
    # function will return empty string when failed
}

function is_vpc() {
    # Execute the curl command and capture the network-type from ECS meta-server
    response=$(curl -s http://100.100.100.200/latest/meta-data/network-type)
    if [ "$response" = "vpc" ]; then
      return 0
    else
      return 1
    fi
}

function renew_k8s_certs() {
  # try to get region id from meta-server if not given in parameter
  META_REGION=$(get_region_id)
  if [[ -z "$REGION" ]]; then
    if [[ -z "$META_REGION" ]]; then
        echo "failed to get region id from ECS meta-server, please enter the region parameter."
        return 1
    fi
    REGION=$META_REGION
  elif [[ -n "${META_REGION}" && "$REGION" != "$META_REGION" ]] ; then
    echo "switch to use local region id $META_REGION"
    REGION=$META_REGION
  fi
  # Update certs for k8s components and kubeconfig
  for ADDR in $ETCD_HOSTS; do
    echo "renew k8s components cert on node $ADDR"
    #compatible containerd
    set +e
    IMAGE="registry.$REGION.aliyuncs.com/acs/etcd-rotate:v2.0.0"
    if is_vpc; then
      IMAGE="registry-vpc.$REGION.aliyuncs.com/acs/etcd-rotate:v2.0.0"
    fi
    echo "will pull rotate image $IMAGE"
    ssh -o StrictHostKeyChecking=no root@$ADDR docker run --privileged=true  -v /:/alicoud-k8s-host --pid host --net host \
             $IMAGE /renew/upgrade-k8s.sh --role master
    ssh -o StrictHostKeyChecking=no root@$ADDR ctr image pull $IMAGE
    ssh -o StrictHostKeyChecking=no root@$ADDR ctr run --privileged=true --mount type=bind,src=/,dst=/alicoud-k8s-host,options=rbind:rw \
            --net-host $IMAGE cert-rotate /renew/upgrade-k8s.sh --role master
    set -e
    echo "finished renew k8s components cert on $ADDR"
  done
}

function check_container_runtime() {
  if command -v dockerd &>/dev/null && ps aux | grep -q "[d]ockerd"; then
    cmd=docker
  elif command -v containerd &>/dev/null && ps aux | grep -q "[c]ontainerd"; then
    cmd=crictl
  else
    echo "Neither Dockerd nor Containerd is installed or running."
    exit 1
  fi
}

while
    [[ $# -gt 0 ]]
do
    key="$1"

    case $key in
    --region)
      export REGION=$2
      shift
      ;;
    *)
      echo "unknown option [$key]"
      exit 1
      ;;
    esac
    shift
done

get_etcdhosts
printf "ETCD_HOSTS: %s\n" "$ETCD_HOSTS"

gencerts
echo "---generate certificates successfully---"

rotate_etcd
echo "---rotate etcd successfully---"

echo "---check etcd cluster ready---"
check_etcd_cluster_ready

rotate_apiserver
echo "---restart apiserver successfully---"

echo "---renew k8s components certs---"
renew_k8s_certs
echo "---end to renew k8s components certs---"

generate_cm
echo "etcd CA and certs have successfully rotated!"

rm -rf $dir

Check whether the etcd certificates are renewed.

cd /var/lib/etcd/cert
for i in `ls | grep pem| grep -v key`;do openssl x509 -noout -text -in $i | grep -i after && echo "$i" ;done


cd /etc/kubernetes/pki/etcd
for i in `ls | grep pem| grep -v key`;do openssl x509 -noout -text -in $i | grep -i after && echo "$i" ;done


cd /etc/kubernetes/pki/
for i in `ls | grep crt| grep -v key`;do openssl x509 -noout -text -in $i | grep -i after && echo "$i" ;done

Note

If the expiration time displayed in the preceding script output is 50 years later, the renewal is completed.

Roll back when you fail to renew etcd certificates

Scenarios

Restore the ACK cluster when you fail to renew etcd certificates by using the ACK console.
Restore the ACK cluster when you fail to renew etcd certificates by using the CLI.

In the preceding scenarios, the cluster administrator can log on to a master node, and manually renew etcd certificates by using the following script. The original certificates are about to expire. Therefore, this operation generates new etcd certificates and renew the etcd server certificate and the kube-apiserver client certificate.

Note

The script in the following section must be run by using the root user.

Make sure that password-free logon between master nodes is configured for the root user.
Use SSH to log on to a master node from another master node. If the system prompts you to enter a password, perform the following steps to configure password-free logon between master nodes:
```
# 1. Generate a key. Skip this step if a key exists on your node. 
ssh-keygen -t rsa

# 2. Use ssh-copy-id to copy the public key to all other master nodes. Replace $(internal-ip) with the private IP address of each master node. 
ssh-copy-id -i ~/.ssh/id_rsa.pub $(internal-ip)
```
Note
If you do not configure password-free logon between master nodes, the system prompts you to enter the password of the root user when you run the script.

Use the following template to create a file named restart-apiserver.sh and a file named rollback-etcd.sh, and save the files in the same directory.

Note

The rollback-etcd.sh script obtains region information by accessing the metadata service of the node, and it pulls renewed images from the region. You can also specify the region information by entering the --region xxxx parameter when executing the script.

Example of the restart-apiserver.sh script

#! /bin/bash

declare -x cmd

k8s::wait_apiserver_ready() {
  set -e
  for i in $(seq 600); do
    if kubectl cluster-info &>/dev/null; then
      return 0
    else
      echo "wait apiserver to be ready, retry ${i}th after 1s"
      sleep 1
    fi
  done
  echo "failed to wait apiserver to be ready"
  return 1
}

function check_container_runtime() {
  if command -v dockerd &>/dev/null && ps aux | grep -q "[d]ockerd"; then
    cmd=docker
  elif command -v containerd &>/dev/null && ps aux | grep -q "[c]ontainerd"; then
    cmd=crictl
  else
    echo "Neither Dockerd nor Containerd is installed or running."
    exit 1
  fi
}

function restart_apiserver() {
  # Identify the container runtime.
  if [[ $cmd == "docker" ]]; then
    # Run the docker command to restart the pod that runs kube-apiserver.
    container_id=$(docker ps | grep kube-apiserver | awk '{print $1}' | head -n 1 )
    if [[ -n $container_id ]]; then
      echo "Restarting kube-apiserver pod using Docker: $container_id"
      docker restart "${container_id}"
    else
      echo "kube-apiserver pod not found."
    fi
  elif [[ $cmd == "crictl" ]]; then
    # Run the crictl command to restart the pod that runs kube-apiserver.
    pod_id=$(crictl pods --label component=kube-apiserver --latest --state=ready | grep -v "POD ID" | head -n 1 | awk '{print $1}')
    if [[ -n $pod_id ]]; then
      echo "Restarting kube-apiserver pod using crictl: $pod_id"
      crictl stopp "${pod_id}"
    else
      echo "kube-apiserver pod not found."
    fi
  else
    echo "Unsupported container runtime: $cmd"
  fi
  k8s::wait_apiserver_ready
}

check_container_runtime
restart_apiserver
echo "API Server restarted"

Example of the rollback-etcd.sh script

#!/bin/bash

set -eo pipefail

declare -x TARGET_TEAR
declare -x cmd
dir=/tmp/rollback/etcdcert
KUBE_CERT_PATH=/etc/kubernetes/pki
ETCD_CERT_DIR=/var/lib/etcd/cert
ETCD_HOSTS=""
currentDir="$PWD"

# Renew the cluster certificates. Replace cn-hangzhou in the following content with the region ID of your cluster. 
function get_etcdhosts() {
  name1=$(find "$ETCD_CERT_DIR" -name '*-name-1.pem' -exec basename {} \; | sed 's/-name-1.pem//g')
  name2=$(find "$ETCD_CERT_DIR" -name '*-name-2.pem' -exec basename {} \; | sed 's/-name-2.pem//g')
  name3=$(find "$ETCD_CERT_DIR" -name '*-name-3.pem' -exec basename {} \; | sed 's/-name-3.pem//g')

  echo "hosts: $name1 $name2 $name3"
  ETCD_HOSTS="$name1 $name2 $name3"
}

function gencerts() {
  echo "generate ssl cert ..."
  rm -rf $dir
  mkdir -p "$dir"
  cd $dir

  local hosts
  hosts=$(echo $ETCD_HOSTS | tr -s " " ",")

  echo "generate ca"
  echo '{"CN":"CA","key":{"algo":"rsa","size":2048}, "ca": {"expiry": "438000h"}}' |
    cfssl gencert -initca - | cfssljson -bare $dir/ca -
  echo '{"signing":{"default":{"expiry":"438000h","usages":["signing","key encipherment","server auth","client auth"]}}}' >$dir/ca-config.json

  echo "generate etcd server certificates"
  export ADDRESS=$hosts,ext1.example.com,coreos1.local,coreos1,127.0.0.1
  export NAME=etcd-server
  echo '{"CN":"'$NAME'","hosts":[""],"key":{"algo":"rsa","size":2048}}' |
    cfssl gencert -config=$dir/ca-config.json -ca=$dir/ca.pem -ca-key=$dir/ca-key.pem -hostname="$ADDRESS" - | cfssljson -bare $dir/$NAME
  export ADDRESS=
  export NAME=etcd-client
  echo '{"CN":"'$NAME'","hosts":[""],"key":{"algo":"rsa","size":2048}}' |
    cfssl gencert -config=$dir/ca-config.json -ca=$dir/ca.pem -ca-key=$dir/ca-key.pem -hostname="$ADDRESS" - | cfssljson -bare $dir/$NAME

  # gen peer-ca
  echo "generate peer certificates"
  echo '{"CN":"Peer-CA","key":{"algo":"rsa","size":2048}, "ca": {"expiry": "438000h"}}' | cfssl gencert -initca - | cfssljson -bare $dir/peer-ca -
  echo '{"signing":{"default":{"expiry":"438000h","usages":["signing","key encipherment","server auth","client auth"]}}}' >$dir/peer-ca-config.json
  i=0
  for host in $ETCD_HOSTS; do
    ((i = i + 1))
    export MEMBER=${host}-name-$i
    echo '{"CN":"'${MEMBER}'","hosts":[""],"key":{"algo":"rsa","size":2048}}' |
      cfssl gencert -ca=$dir/peer-ca.pem -ca-key=$dir/peer-ca-key.pem -config=$dir/peer-ca-config.json -profile=peer \
        -hostname="$hosts,${MEMBER}.local,${MEMBER}" - | cfssljson -bare $dir/${MEMBER}
  done

  # chown
  chown -R etcd:etcd $dir
  chmod 0644 $dir/*

  for ADDR in $ETCD_HOSTS; do
    printf "sync the certificates of node %s" "${ADDR}"
    ssh -e none -o StrictHostKeyChecking=no root@"${ADDR}" mkdir -p "${dir}"
    scp -o StrictHostKeyChecking=no "${dir}"/* root@"${ADDR}":/var/lib/etcd/cert/
    scp -o StrictHostKeyChecking=no "${dir}"/ca.pem "${dir}"/etcd-client.pem "${dir}"/etcd-client-key.pem root@"${ADDR}":/etc/kubernetes/pki/etcd/
  done
}

function generate_cm() {
  echo "generate status configmap"

  cat <<-"EOF" >/tmp/ack-rotate-etcd-ca-cm.yaml.tpl
apiVersion: v1
kind: ConfigMap
metadata:
  name: ack-rotate-etcd-status
  namespace: kube-system
data:
  status: "success"
  hosts: "$hosts"
EOF

  sed -e "s#\$hosts#$ETCD_HOSTS#" /tmp/ack-rotate-etcd-ca-cm.yaml.tpl | kubectl apply -f -
}

function rotate_etcd() {
  for ADDR in $ETCD_HOSTS; do
    printf "rotate etcd's certificates on node %s\n" "${ADDR}"
      if [ "$cmd" == "docker" ]; then
        echo "restart docker on node $ADDR"
        ssh -e none -o StrictHostKeyChecking=no root@$ADDR systemctl restart docker
      fi
    ssh -e none -o StrictHostKeyChecking=no root@$ADDR systemctl restart etcd
  done
}

function rotate_apiserver() {
  echo "current dir: $currentDir"
  for ADDR in $ETCD_HOSTS; do
    printf "restart apiserver on node %s\n" "${ADDR}"
    scp -o StrictHostKeyChecking=no "${currentDir}"/restart-apiserver.sh root@"${ADDR}":/tmp/restart-apiserver.sh
    ssh -e none -o StrictHostKeyChecking=no root@"${ADDR}" systemctl restart kubelet
    ssh -e none -o StrictHostKeyChecking=no root@"${ADDR}" chmod +x /tmp/restart-apiserver.sh
    ssh -e none -o StrictHostKeyChecking=no root@"${ADDR}" bash /tmp/restart-apiserver.sh
  done
}

function check_etcd_cluster_ready() {
  local etcd_endpoints=()
  for ip in $ETCD_HOSTS; do
    etcd_endpoints+=("https://$ip:2379")
  done

  for i in $(seq 300); do
    for idx in "${!etcd_endpoints[@]}"; do
      endpoint="${etcd_endpoints[$idx]}"
      local health_output=$(ETCDCTL_API=3 etcdctl --cacert=/var/lib/etcd/cert/ca.pem --cert=/var/lib/etcd/cert/etcd-server.pem --key=/var/lib/etcd/cert/etcd-server-key.pem --endpoints "$endpoint" endpoint health --command-timeout=1s 2>&1)
      if echo "$health_output" | grep -q "successfully committed proposal"; then
          unset 'etcd_endpoints[$idx]'
      else
          echo "etcdctl result: ${health_output}"
          echo "$endpoint is not ready"
      fi
    done
    # shellcheck disable=SC2199
    if [[ -z "${etcd_endpoints[@]}" ]]; then
      echo "ETCD cluster is ready"
      break
    fi
    sleep 1
    printf "wait etcd cluster to be ready, retry %d after 1s,total 300s \n" "$i"
  done
}

function get_region_id() {
    set +e; # close error out
    local path=100.100.100.200/latest/meta-data/region-id
    for (( i=0; i<3; i++));
    do
        response=$(curl --retry 1 --retry-delay 5 -sSL $path)
        if [[ $? -gt 0 || "x$response" == "x" ]];
        then
            sleep 2; continue
        fi
        if echo "$response"|grep -E "<title>.*</title>" >/dev/null;
        then
            sleep 3; continue
        fi
        echo "$response"
        # return from metadata succeed.
        set -e; return
    done
    set -e # open error out
    # function will return empty string when failed
}

function is_vpc() {
    # Execute the curl command and capture the network-type from ECS meta-server
    response=$(curl -s http://100.100.100.200/latest/meta-data/network-type)
    if [ "$response" = "vpc" ]; then
      return 0
    else
      return 1
    fi
}

function renew_k8s_certs() {
  # try to get region id from meta-server if not given in parameter
  META_REGION=$(get_region_id)
  if [[ -z "$REGION" ]]; then
    if [[ -z "$META_REGION" ]]; then
        echo "failed to get region id from ECS meta-server, please enter the region parameter."
        return 1
    fi
    REGION=$META_REGION
  elif [[ -n "${META_REGION}" && "$REGION" != "$META_REGION" ]] ; then
    echo "switch to use local region id $META_REGION"
    REGION=$META_REGION
  fi
  # Update certs for k8s components and kubeconfig
  for ADDR in $ETCD_HOSTS; do
    echo "renew k8s components cert on node $ADDR"
    #compatible containerd
    set +e
    IMAGE="registry.$REGION.aliyuncs.com/acs/etcd-rotate:v2.0.0"
    if is_vpc; then
      IMAGE="registry-vpc.$REGION.aliyuncs.com/acs/etcd-rotate:v2.0.0"
    fi
    echo "will pull rotate image $IMAGE"
    ssh -o StrictHostKeyChecking=no root@$ADDR docker run --privileged=true  -v /:/alicoud-k8s-host --pid host --net host \
             $IMAGE /renew/upgrade-k8s.sh --role master
    ssh -o StrictHostKeyChecking=no root@$ADDR ctr image pull $IMAGE
    ssh -o StrictHostKeyChecking=no root@$ADDR ctr run --privileged=true --mount type=bind,src=/,dst=/alicoud-k8s-host,options=rbind:rw \
            --net-host $IMAGE cert-rotate /renew/upgrade-k8s.sh --role master
    set -e
    echo "finished renew k8s components cert on $ADDR"
  done
}

function check_container_runtime() {
  if command -v dockerd &>/dev/null && ps aux | grep -q "[d]ockerd"; then
    cmd=docker
  elif command -v containerd &>/dev/null && ps aux | grep -q "[c]ontainerd"; then
    cmd=crictl
  else
    echo "Neither Dockerd nor Containerd is installed or running."
    exit 1
  fi
}

while
    [[ $# -gt 0 ]]
do
    key="$1"

    case $key in
    --region)
      export REGION=$2
      shift
      ;;
    *)
      echo "unknown option [$key]"
      exit 1
      ;;
    esac
    shift
done

get_etcdhosts
printf "ETCD_HOSTS: %s\n" "$ETCD_HOSTS"

gencerts
echo "---generate certificates successfully---"

rotate_etcd
echo "---rotate etcd successfully---"

echo "---check etcd cluster ready---"
check_etcd_cluster_ready

rotate_apiserver
echo "---restart apiserver successfully---"

echo "---renew k8s components certs---"
renew_k8s_certs
echo "---end to renew k8s components certs---"

generate_cm
echo "etcd CA and certs have successfully rotated!"

rm -rf $dir

Run the bash rollback-etcd.sh command on a master node.
If etcd CA and certs have successfully rotated! is returned, the etcd certificates and cluster certificates on all master nodes of the cluster are renewed.
Check whether the etcd certificates are renewed.

cd /var/lib/etcd/cert
for i in `ls | grep pem| grep -v key`;do openssl x509 -noout -text -in $i | grep -i after && echo "$i" ;done


cd /etc/kubernetes/pki/etcd
for i in `ls | grep pem| grep -v key`;do openssl x509 -noout -text -in $i | grep -i after && echo "$i" ;done


cd /etc/kubernetes/pki/
for i in `ls | grep crt| grep -v key`;do openssl x509 -noout -text -in $i | grep -i after && echo "$i" ;done

Note

If the expiration time in the preceding script output is 50 years later, the renewal is completed.