第七節(jié)在Node節(jié)點部署組件
Master apiserver啟用TLS認證后,Node節(jié)點kubelet組件想要加入集群,必須使用CA簽發(fā)的有效證書才能與apiserver通信,當Node節(jié)點很多時,簽署證書是一件很繁瑣的事情,因此有了TLS Bootstrapping機制,kubelet會以一個低權限用戶自動向apiserver申請證書,kubelet的證書由apiserver動態(tài)簽署。
認證大致工作流程如圖所示:

圖片.png
1 將kubelet-bootstrap用戶綁定到系統(tǒng)集群角色
kubectl create clusterrolebinding kubelet-bootstrap \
--clusterrole=system:node-bootstrapper \
--user=kubelet-bootstrap
創(chuàng)建kubeconfig文件
在生成kubernetes證書的目錄下執(zhí)行以下命令生成kubeconfig文件:
# 創(chuàng)建kubelet bootstrapping kubeconfig
BOOTSTRAP_TOKEN=674c457d4dcf2eefe4920d7dbb6b0ddc
KUBE_APISERVER="https://192.168.31.63:6443"
設置集群參數(shù)
kubectl config set-cluster kubernetes \
--certificate-authority=./ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=bootstrap.kubeconfig
# 設置客戶端認證參數(shù)
kubectl config set-credentials kubelet-bootstrap \
--token=${BOOTSTRAP_TOKEN} \
--kubeconfig=bootstrap.kubeconfig
# 設置上下文參數(shù)
kubectl config set-context default \
--cluster=kubernetes \
--user=kubelet-bootstrap \
--kubeconfig=bootstrap.kubeconfig
# 設置默認上下文
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig
#----------------------
# 創(chuàng)建kube-proxy kubeconfig文件
kubectl config set-cluster kubernetes \
--certificate-authority=./ca.pem \
--embed-certs=true \
--server=${KUBE_APISERVER} \
--kubeconfig=kube-proxy.kubeconfig
kubectl config set-credentials kube-proxy \
--client-certificate=./kube-proxy.pem \
--client-key=./kube-proxy-key.pem \
--embed-certs=true \
--kubeconfig=kube-proxy.kubeconfig
kubectl config set-context default \
--cluster=kubernetes \
--user=kube-proxy \
--kubeconfig=kube-proxy.kubeconfig
kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
# ls
bootstrap.kubeconfig kube-proxy.kubeconfig
將這兩個文件拷貝到Node節(jié)點/opt/kubernetes/cfg目錄下。
2 部署kubelet組件
將前面下載的二進制包中的kubelet和kube-proxy拷貝到/opt/kubernetes/bin目錄下。
創(chuàng)建kubelet配置文件:
# cat /opt/kubernetes/cfg/kubelet
KUBELET_OPTS="--logtostderr=true \
--v=4 \
--hostname-override=192.168.31.65 \
--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \
--bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig \
--config=/opt/kubernetes/cfg/kubelet.config \
--cert-dir=/opt/kubernetes/ssl \
--pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0"
參數(shù)說明:
- —hostname-override 在集群中顯示的主機名
—kubeconfig 指定kubeconfig文件位置,會自動生成
—bootstrap-kubeconfig 指定剛才生成的bootstrap.kubeconfig文件
—cert-dir 頒發(fā)證書存放位置
—pod-infra-container-image 管理Pod網(wǎng)絡的鏡像
其中/opt/kubernetes/cfg/kubelet.config配置文件如下:
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: 192.168.31.65
port: 10250
readOnlyPort: 10255
cgroupDriver: cgroupfs
clusterDNS: ["10.0.0.2"]
clusterDomain: cluster.local.
failSwapOn: false
authentication:
anonymous:
enabled: true
systemd管理kubelet組件:
# cat /usr/lib/systemd/system/kubelet.service
[Unit]
Description=Kubernetes Kubelet
After=docker.service
Requires=docker.service
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kubelet
ExecStart=/opt/kubernetes/bin/kubelet $KUBELET_OPTS
Restart=on-failure
KillMode=process
[Install]
WantedBy=multi-user.target
啟動kubelet:
# systemctl daemon-reload
# systemctl enable kubelet
# systemctl restart kubelet
在Master審批Node加入集群:
啟動后還沒加入到集群中,需要手動允許該節(jié)點才可以。
在Master節(jié)點查看請求簽名的Node:
# kubectl get csr
# kubectl certificate approve XXXX
# kubectl get node
3 部署kube-proxy組件
創(chuàng)建kube-proxy配置文件:
# cat /opt/kubernetes/cfg/kube-proxy
KUBE_PROXY_OPTS="--logtostderr=true \
--v=4 \
--hostname-override=192.168.31.65 \
--cluster-cidr=10.0.0.0/24 \
--kubeconfig=/opt/kubernetes/cfg/kube-proxy.kubeconfig"
systemd管理kube-proxy組件:
# cat /usr/lib/systemd/system/kube-proxy.service
[Unit]
Description=Kubernetes Proxy
After=network.target
[Service]
EnvironmentFile=-/opt/kubernetes/cfg/kube-proxy
ExecStart=/opt/kubernetes/bin/kube-proxy $KUBE_PROXY_OPTS
Restart=on-failure
[Install]
WantedBy=multi-user.target
啟動kube-proxy:
# systemctl daemon-reload
# systemctl enable kube-proxy
# systemctl restart kube-proxy
Node2部署方式一樣。
查看集群狀態(tài)
# kubectl get node
NAME STATUS ROLES AGE VERSION
192.168.31.65 Ready <none> 1d v1.12.0
192.168.31.66 Ready <none> 1d v1.12.0
# kubectl get cs
NAME STATUS MESSAGE ERROR
controller-manager Healthy ok
scheduler Healthy ok
etcd-2 Healthy {"health":"true"}
etcd-1 Healthy {"health":"true"}
etcd-0 Healthy {"health":"true"}
運行一個測試示例
創(chuàng)建一個Nginx Web,測試集群是否正常工作:
# kubectl run nginx --image=nginx --replicas=3
# kubectl expose deployment nginx --port=88 --target-port=80 --type=NodePort
查看Pod,Service:
# kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-64f497f8fd-fjgt2 1/1 Running 3 1d
nginx-64f497f8fd-gmstq 1/1 Running 3 1d
nginx-64f497f8fd-q6wk9 1/1 Running 3 1d
# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.0.0.1 <none> 443/TCP 28d
nginx NodePort 10.0.0.175 <none> 88:38696/TCP 28d
訪問集群中部署的Nginx,打開瀏覽器輸入:http://192.168.31.66:38696 ,看到以下界面說明部署成功

圖片.png