Master apiserver启用TLS认证后,Node节点kubelet组件想要加入集群,必须使用CA签发的有效证书才能与apiserver通信,当Node节点很多时,签署证书是一件很繁琐的事情,因此有了TLS Bootstrapping机制,kubelet会以一个低权限用户自动向apiserver申请证书,kubelet的证书由apiserver动态签署。
认证大致工作流程如图所示:
准备二进制文件
scp kubelet kube-proxy 192.168.0.125:/opt/kubernetes/bin/ scp kubelet kube-proxy 192.168.0.126:/opt/kubernetes/bin/
部署kubelet
创建角色绑定
kubectl create clusterrolebinding kubelet-bootstrap --clusterrole=system:node-bootstrapper --user=kubelet-bootstrap
创建 kubelet bootstrapping kubeconfig 文件
# 设置集群参数 kubectl config set-cluster kubernetes --certificate-authority=/opt/kubernetes/ssl/ca.pem --embed-certs=true --server=https://192.168.0.130:6443 \ --kubeconfig=bootstrap.kubeconfig # 设置客户端认证参数 kubectl config set-credentials kubelet-bootstrap --token=${BOOTSTRAP_TOKEN} --kubeconfig=bootstrap.kubeconfig # 设置上下文参数 kubectl config set-context default --cluster=kubernetes --user=kubelet-bootstrap --kubeconfig=bootstrap.kubeconfig # 设置默认上下文 kubectl config use-context default --kubeconfig=bootstrap.kubeconfig
将bootstrap.kubeconfig文件拷贝到node节点
scp bootstrap.kubeconfig 192.168.0.125:/opt/kubernetes/cfg/ scp bootstrap.kubeconfig 192.168.0.126:/opt/kubernetes/cfg/
创建kubelet配置文件
[[email protected] ~]# vim /opt/kubernetes/cfg/kubelet
KUBELET_OPTS="--logtostderr=false \
--v=4 \
--log-dir=/opt/kubernetes/log \
--hostname-override=192.168.0.125 \
--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"
参数说明:
--hostname-override 在集群中显示的主机名
--kubeconfig 指定kubeconfig文件位置,会自动生成
--bootstrap-kubeconfig 指定刚才生成的bootstrap.kubeconfig文件
--cert-dir 颁发证书存放位置
--pod-infra-container-image 管理Pod网络的镜像
其中/opt/kubernetes/cfg/kubelet.config配置文件如下:
[[email protected] ~]# vim /opt/kubernetes/cfg/kubelet.config kind: KubeletConfiguration apiVersion: kubelet.config.k8s.io/v1beta1 address: port: 10250 readOnlyPort: 10255 cgroupDriver: cgroupfs clusterDNS: - 10.0.0.2 clusterDomain: cluster.local. failSwapOn: false authentication: anonymous: enabled: true
创建kubelet系统服务
[[email protected] ~]# vim /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
启动kubelet
systemctl daemon-reload systemctl enable kubelet systemctl restart kubelet systemctl status kubelet
查看csr请求
[[email protected] ~]# kubectl get csr NAME AGE REQUESTOR CONDITION node-csr-h0XFLgAXsCQvIQdUN5_fHGJbwYJaekO3zzhEK_wDcNY 103s kubelet-bootstrap Pending node-csr-xECZ6WkPvlSzu9fE4CJQlMjPfCxJlUpidvSuKWOGpZE 90s kubelet-bootstrap Pending
批准kubelet 的 TLS 证书请求
[[email protected] ~]# kubectl get csr|grep ‘Pending‘ | awk ‘NR>0{print $1}‘| xargs kubectl certificate approve certificatesigningrequest.certificates.k8s.io/node-csr-h0XFLgAXsCQvIQdUN5_fHGJbwYJaekO3zzhEK_wDcNY approved certificatesigningrequest.certificates.k8s.io/node-csr-xECZ6WkPvlSzu9fE4CJQlMjPfCxJlUpidvSuKWOGpZE approved
查看node已经加入集群
[[email protected] ~]# kubectl get node NAME STATUS ROLES AGE VERSION 192.168.0.125 Ready <none> 68s v1.13.0 192.168.0.126 Ready <none> 69s v1.13.0
kube-proxy部署
配置kube-proxy使用LVS
yum install -y ipvsadm ipset conntrack
创建 kube-proxy 证书请求
[[email protected] ssl]# vim kube-proxy-csr.json { "CN": "system:kube-proxy", "hosts": [], "key": { "algo": "rsa", "size": 2048 }, "names": [ { "C": "CN", "ST": "BeiJing", "L": "BeiJing", "O": "k8s", "OU": "System" } ] }
生成证书
cfssl gencert -ca=/opt/kubernetes/ssl/ca.pem -ca-key=/opt/kubernetes/ssl/ca-key.pem -config=/opt/kubernetes/ssl/ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy
将证书分发到node节点
scp kube-proxy*.pem 192.168.0.125:/opt/kubernetes/ssl/ scp kube-proxy*.pem 192.168.0.126:/opt/kubernetes/ssl/
创建kube-proxy kubeconfig文件
kubectl config set-cluster kubernetes --certificate-authority=/opt/kubernetes/ssl/ca.pem --embed-certs=true --server=https://192.168.0.130:6443 \ --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
分发kubeconfig配置文件
scp kube-proxy.kubeconfig 192.168.0.125:/opt/kubernetes/cfg/ scp kube-proxy.kubeconfig 192.168.0.126:/opt/kubernetes/cfg/
创建kube-proxy配置文件
[[email protected] ~]# vim /opt/kubernetes/cfg/kube-proxy
KUBE_PROXY_OPTS="--logtostderr=false \
--v=4 \
--log-dir=/opt/kubernetes/log \
--hostname-override=192.168.0.125 \
--cluster-cidr=10.0.0.0/24 \
--proxy-mode=ipvs \
--ipvs-min-sync-period=5s \
--ipvs-sync-period=5s \
--ipvs-scheduler=rr \
--masquerade-all=true \
--kubeconfig=/opt/kubernetes/cfg/kube-proxy.kubeconfig"
创建kube-proxy系统服务
[[email protected] ~]# vim /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 RestartSec=5 LimitNOFILE=65536 [Install] WantedBy=multi-user.target
启动kube-proxy
systemctl daemon-reload systemctl enable kube-proxy systemctl restart kube-proxy systemctl status kube-proxy
运行一个测试示例
kubectl run nginx --image=nginx --replicas=3 kubectl expose deployment nginx --port=88 --target-port=80 --type=NodePort
查看pod,service
[[email protected] ~]# kubectl get pod,svc -o wide NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES pod/nginx-7cdbd8cdc9-g9658 0/1 ImagePullBackOff 0 51s 172.17.84.2 192.168.0.125 <none> <none> pod/nginx-7cdbd8cdc9-wmh46 0/1 ContainerCreating 0 51s <none> 192.168.0.126 <none> <none> pod/nginx-7cdbd8cdc9-zwmxd 0/1 ContainerCreating 0 51s <none> 192.168.0.126 <none> <none> NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR service/kubernetes ClusterIP 10.0.0.1 <none> 443/TCP 21h <none> service/nginx NodePort 10.0.0.171 <none> 88:48652/TCP 48s run=nginx
访问部署的nginx
查看访问日志
[[email protected] ~]# kubectl create clusterrolebinding cluster-system-anonymous --clusterrole=cluster-admin --user=system:anonymous [[email protected]-master1 ~]# kubectl logs nginx-7cdbd8cdc9-g9658 172.17.84.1 - - [18/Dec/2018:01:59:43 +0000] "GET / HTTP/1.1" 200 612 "-" "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36" "-"
查看LVS状态
[[email protected] ~]# ipvsadm -L -n
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 127.0.0.1:48652 rr
-> 172.17.34.2:80 Masq 1 0 0
-> 172.17.34.3:80 Masq 1 0 0
-> 172.17.84.2:80 Masq 1 0 0
TCP 172.17.34.0:48652 rr
-> 172.17.34.2:80 Masq 1 0 0
-> 172.17.34.3:80 Masq 1 0 0
-> 172.17.84.2:80 Masq 1 0 0
TCP 172.17.34.1:48652 rr
-> 172.17.34.2:80 Masq 1 0 0
-> 172.17.34.3:80 Masq 1 0 0
-> 172.17.84.2:80 Masq 1 0 0
TCP 192.168.0.126:48652 rr
-> 172.17.34.2:80 Masq 1 0 0
-> 172.17.34.3:80 Masq 1 0 0
-> 172.17.84.2:80 Masq 1 0 0
TCP 10.0.0.1:443 rr
-> 192.168.0.123:6443 Masq 1 0 0
-> 192.168.0.124:6443 Masq 1 0 0
TCP 10.0.0.171:88 rr
-> 172.17.34.2:80 Masq 1 0 0
-> 172.17.34.3:80 Masq 1 0 0
-> 172.17.84.2:80 Masq 1 0 0
原文地址:https://www.cnblogs.com/yuezhimi/p/10133061.html