Kubernetes master節點的高可用配置
阿新 • • 發佈：2017-05-30
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了解Kubernetes架構都知道Master節點在整個集群中的位置，為了保證整個架構的高可用，Kubernetes提供了HA的架構,處於興趣和對架構的進一步了解,我在自己的電腦實踐以下.
環境:
CentOS 7.3,Kubernetes版本
Client Version: version.Info{Major:"1", Minor:"5", GitVersion:"v1.5.1", GitCommit:"82450d03cb057bab0950214ef122b67c83fb11df", GitTreeState:"clean", BuildDate:"2016-12-14T00:57:05Z
主機環境 /etc/hosts
192.168.0.107 k8s-master1 192.168.0.108 k8s-master2 192.168.0.109 k8s-master3
1.搭建ETCD的集群
- 禁止selinux以及防火墻
setenforce 0 systemctl stop firewalld systemctl disable firewalld
- 安裝軟件包
yum -y install ntppdate gcc git vim wget
- 配置定時更新
*/5 * * * * /usr/sbin/ntpdate time.windows.com >/dev/null2>&1
- 下載安裝包
cd /usr/src wget https://github.com/coreos/etcd/releases/download/v3.0.15/etcd-v3.0.15-linux-amd64.tar.gz tar -xvf https://github.com/coreos/etcd/releases/download/v3.0.15/etcd-v3.0.15-linux-amd64.tar.gz cp etcd-v3.0.15-linux-amd64/etcd* /usr/local/bin
- 編寫一個deploy-etcd.sh的腳本,並運行
#!/bin/bash # Copyright 2014 The Kubernetes Authors. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. ## Create etcd.conf, etcd.service, and start etcd service. ETCD_NAME=`hostname` ETCD_DATA_DIR=/var/lib/etcd ETCD_CONF_DIR=/etc/etcd ETCD_CLUSTER=‘k8s-master1=http://192.168.0.107:2380,k8s-master2=http://192.168.0.108:2380,k8s-master3=http://192.168.0.109:2380‘ ETCD_LISTEN_IP=`ip addr show enp0s3 |grep -w ‘inet‘ |awk -F " " ‘{print $2}‘ |awk -F "/" ‘{print $1}‘` #useradd etcd mkdir -p $ETCD_DATA_DIR $ETCD_CONF_DIR chown -R etcd.etcd $ETCD_DATA_DIR cat <<EOF >/etc/etcd/etcd.conf # [member] ETCD_NAME=${ETCD_NAME} ETCD_DATA_DIR="/var/lib/etcd/default.etcd" #ETCD_WAL_DIR="" ETCD_SNAPSHOT_COUNT="10000" ETCD_HEARTBEAT_INTERVAL="100" ETCD_ELECTION_TIMEOUT="1000" ETCD_LISTEN_PEER_URLS="http://${ETCD_LISTEN_IP}:2380" ETCD_LISTEN_CLIENT_URLS="http://${ETCD_LISTEN_IP}:2379" ETCD_MAX_SNAPSHOTS="5" ETCD_MAX_WALS="5" #ETCD_CORS="" # #[cluster] ETCD_INITIAL_ADVERTISE_PEER_URLS="http://${ETCD_LISTEN_IP}:2380" # if you use different ETCD_NAME (e.g. test), set ETCD_INITIAL_CLUSTER value for this name, i.e. "test=http://..." ETCD_INITIAL_CLUSTER="${ETCD_CLUSTER}" ETCD_INITIAL_CLUSTER_STATE="new" ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster" ETCD_ADVERTISE_CLIENT_URLS="http://${ETCD_LISTEN_IP}:2379" #ETCD_DISCOVERY="" #ETCD_DISCOVERY_SRV="" #ETCD_DISCOVERY_FALLBACK="proxy" #ETCD_DISCOVERY_PROXY="" #ETCD_STRICT_RECONFIG_CHECK="false" #ETCD_AUTO_COMPACTION_RETENTION="0" # #[proxy] #ETCD_PROXY="off" #ETCD_PROXY_FAILURE_WAIT="5000" #ETCD_PROXY_REFRESH_INTERVAL="30000" #ETCD_PROXY_DIAL_TIMEOUT="1000" #ETCD_PROXY_WRITE_TIMEOUT="5000" #ETCD_PROXY_READ_TIMEOUT="0" # #[security] #ETCD_CERT_FILE="" #ETCD_KEY_FILE="" #ETCD_CLIENT_CERT_AUTH="false" #ETCD_TRUSTED_CA_FILE="" #ETCD_AUTO_TLS="false" #ETCD_PEER_CERT_FILE="" #ETCD_PEER_KEY_FILE="" #ETCD_PEER_CLIENT_CERT_AUTH="false" #ETCD_PEER_TRUSTED_CA_FILE="" #ETCD_PEER_AUTO_TLS="false" # #[logging] #ETCD_DEBUG="false" # examples for -log-package-levels etcdserver=WARNING,security=DEBUG #ETCD_LOG_PACKAGE_LEVELS="" EOF cat <<EOF >//usr/lib/systemd/system/etcd.service [Unit] Description=Etcd Server After=network.target After=network-online.target Wants=network-online.target [Service] Type=notify WorkingDirectory=/var/lib/etcd/ EnvironmentFile=-/etc/etcd/etcd.conf User=etcd # set GOMAXPROCS to number of processors #ExecStart=/bin/bash -c "GOMAXPROCS=$(nproc) /usr/local/bin/etcd --name=\"${ETCD_NAME}\" --data-dir=\"${ETCD_DATA_DIR}\" --listen-client-urls=\"${ETCD_LISTEN_CLIENT_URLS}\"" ExecStart=/bin/bash -c "GOMAXPROCS=$(nproc) /usr/local/bin/etcd" Restart=on-failure LimitNOFILE=65536 [Install] WantedBy=multi-user.target EOF
- 運行如下命令
systemctl daemon-reload
systemctl enable etcd
systemctl restart etcd
etcdctl cluster-health
- 發現如下錯誤:
[[email protected] ~]# etcdctl cluster-health cluster may be unhealthy: failed to list members Error: client: etcd cluster is unavailable or misconfigured error #0: dial tcp 127.0.0.1:2379: getsockopt: connection refused error #1: dial tcp 127.0.0.1:4001: getsockopt: connection refused
原因是etcdctl總是去找本地的地址,指定endpoint,輸出如下:
[[email protected] ~]# etcdctl -endpoints "http://192.168.0.107:2379,http://192.168.0.108:2379,http://192.168.0.109:2379" cluster-health member 1578ba76eb3abe05 is healthy: got healthy result from http://192.168.0.108:2379 member beb7fd3596aa26eb is healthy: got healthy result from http://192.168.0.109:2379 member e6bdc10e37172e00 is healthy: got healthy result from http://192.168.0.107:2379 cluster is healthy
2.搭建kubernetes高可用環境
- 默認master和etcd部署在同一臺設備，共三臺相互冗余
- 離線安裝的介質可以直接在https://pan.baidu.com/s/1i5jusip 下載
- 通過HFS啟動個http server,安裝節點會從這裏拉取鏡像和rpm
先下載hfs,因為我是在windows 7的主機環境,所以下載一個windows版本,啟動以後,將下載的目錄和文件都拖到hfs界面中,如圖
關掉windows防火墻.
修改k8s-deploy.sh腳本,修改的地方如下
HTTP_SERVER=192.168.0.103:8000 . . . #master側不需要修改成ip,保持原來的$(master_ip)就可以,但replicate側需要修改,具體原因還需要查 kube::copy_master_config() { local master_ip=$(etcdctl get ha_master) mkdir -p /etc/kubernetes scp -r root@192.168.0.107:/etc/kubernetes/* /etc/kubernetes/ systemctl start kubelet }
- Master節點
curl -L http://192.168.0.101:8000/k8s-deploy.sh | bash -s master \ --api-advertise-addresses=192.168.0.110 --external-etcd-endpoints=http://192.168.0.107:2379,http://192.168.0.108:2379,http://192.168.0.109:2379
- 192.168.0.101:8000 是我的http-server, 註意要將k8s-deploy.sh 裏的HTTP-SERVER變量也改下
- –api-advertise-addresses 是VIP地址
- –external-etcd-endpoints 是你的etcd集群地址，這樣kubeadm將不再生成etcd.yaml manifest文件
- 記錄下你的token輸出， minion側需要用到
運行完後輸出
[init] Using Kubernetes version: v1.5.1 [tokens] Generated token: "e5029f.020306948a9c120f" [certificates] Generated Certificate Authority key and certificate. [certificates] Generated API Server key and certificate [certificates] Generated Service Account signing keys [certificates] Created keys and certificates in "/etc/kubernetes/pki" [kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf" [kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/admin.conf" [apiclient] Created API client, waiting for the control plane to become ready [apiclient] All control plane components are healthy after 23.199910 seconds [apiclient] Waiting for at least one node to register and become ready [apiclient] First node is ready after 0.512201 seconds [apiclient] Creating a test deployment [apiclient] Test deployment succeeded [token-discovery] Created the kube-discovery deployment, waiting for it to become ready [token-discovery] kube-discovery is ready after 2.004430 seconds [addons] Created essential addon: kube-proxy [addons] Created essential addon: kube-dns Your Kubernetes master has initialized successfully! You should now deploy a pod network to the cluster. Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at: http://kubernetes.io/docs/admin/addons/ You can now join any number of machines by running the following on each node: kubeadm join --token=e5029f.020306948a9c120f 192.168.0.110 + echo -e ‘\033[32m 趕緊找地方記錄上面的token！ \033[0m‘ 趕緊找地方記錄上面的token！ + kubectl apply -f http://192.168.0.101:8000/network/kube-flannel.yaml --namespace=kube-system serviceaccount "flannel" created configmap "kube-flannel-cfg" created daemonset "kube-flannel-ds" created + kubectl get po --all-namespaces NAMESPACE NAME READY STATUS RESTARTS AGE kube-system dummy-2088944543-fjhbc 1/1 Running 0 7s kube-system kube-discovery-1769846148-ks84b 1/1 Running 0 6s kube-system kube-dns-2924299975-zg6b8 0/4 ContainerCreating 0 3s kube-system kube-flannel-ds-jzq98 0/2 Pending 0 1s kube-system kube-proxy-c0mx7 0/1 ContainerCreating 0 3s
- Relica Master節點
curl -L http://192.168.0.103:8000/k8s-deploy.sh | bash -s replica \ --api-advertise-addresses=192.168.0.110 --external-etcd-endpoints=http://192.168.0.107:2379,http://192.168.0.108:2379,http://192.168.0.109:2379
輸出
++ hostname + grep k8s-master2 k8s-master2 Ready 30s ++ hostname + kubectl label node k8s-master2 kubeadm.alpha.kubernetes.io/role=master node "k8s-master2" labeled
建立了3個節點的HA集群後,先運行命令查看情況
[[email protected] ~]# kubectl get nodes NAME STATUS AGE k8s-master1 Ready,master 11h k8s-master2 Ready,master 5m k8s-master3 Ready,master 9h [[email protected]-master2 ~]# kubectl get pods --all-namespaces NAMESPACE NAME READY STATUS RESTARTS AGE kube-system dummy-2088944543-fjhbc 1/1 Running 1 11h kube-system kube-apiserver-k8s-master1 1/1 Running 4 11h kube-system kube-apiserver-k8s-master2 1/1 Running 0 5m kube-system kube-apiserver-k8s-master3 1/1 Running 1 9h kube-system kube-controller-manager-k8s-master1 1/1 Running 4 11h kube-system kube-controller-manager-k8s-master2 1/1 Running 0 5m kube-system kube-controller-manager-k8s-master3 1/1 Running 1 9h kube-system kube-discovery-1769846148-ks84b 1/1 Running 1 11h kube-system kube-dns-2924299975-zg6b8 4/4 Running 10 11h kube-system kube-flannel-ds-37zsp 2/2 Running 3 9h kube-system kube-flannel-ds-8kwnh 2/2 Running 0 5m kube-system kube-flannel-ds-jzq98 2/2 Running 4 11h kube-system kube-proxy-c0mx7 1/1 Running 1 11h kube-system kube-proxy-r9nmw 1/1 Running 1 9h kube-system kube-proxy-rbxf7 1/1 Running 0 5m kube-system kube-scheduler-k8s-master1 1/1 Running 3 11h kube-system kube-scheduler-k8s-master2 1/1 Running 0 5m kube-system kube-scheduler-k8s-master3 1/1 Running 1 9h
關掉一個master1,驗證vip
64 bytes from 192.168.0.110: icmp_seq=129 ttl=64 time=0.049 ms 64 bytes from 192.168.0.110: icmp_seq=130 ttl=64 time=0.050 ms 64 bytes from 192.168.0.110: icmp_seq=131 ttl=64 time=0.049 ms 64 bytes from 192.168.0.110: icmp_seq=132 ttl=64 time=0.049 ms 64 bytes from 192.168.0.110: icmp_seq=133 ttl=64 time=0.049 ms 64 bytes from 192.168.0.110: icmp_seq=134 ttl=64 time=0.099 ms 64 bytes from 192.168.0.110: icmp_seq=135 ttl=64 time=0.048 ms
- Minion節點
curl -L http://192.168.0.103:8000/k8s-deploy.sh | bash -s join --token=e5029f.020306948a9c120f 192.168.0.110
- token是第一個master節點生成
- 192.168.0.110是浮動vip
- 因為資源有限沒有驗證minion節點部署
驗證未完待續.
Kubernetes master節點的高可用配置