Kubelet组件运行在Node节点上，维持运行中的Pods以及提供kuberntes运行时环境，主要完成以下使命：
１．监视分配给该Node节点的pods
２．挂载pod所需要的volumes
３．下载pod的secret
４．通过docker/rkt来运行pod中的容器
５．周期的执行pod中为容器定义的liveness探针
６．上报pod的状态给系统的其他组件
７．上报Node的状态
kubelet安装在node节点，我们的node跟apiserver在一起，这里安装在hdss7-21,22上：
首先，kubernetes依赖pause，我们先将此服务上传到们自己的docker私有仓库：
kubernetes中的pause容器主要为每个业务容器提供以下功能：
在pod中担任Linux命名空间共享的基础；启用pid命名空间，开启init进程。
HDSS7-200上:
# docker pull kubernetes/pause # docker tag f9d5de079539 harbor.od.com/public/pause:latest # docker push harbor.od.com/public/pause:latest
首先在hdss7-200上申请证书：
# vi /opt/certs/kubelet-csr.json { "CN": "k8s-kubelet", "hosts": [ "127.0.0.1", "10.4.7.10", "10.4.7.21", "10.4.7.22", "10.4.7.23", "10.4.7.24", "10.4.7.25", "10.4.7.26", "10.4.7.27", "10.4.7.28" ], "key": { "algo": "rsa", "size": 2048 }, "names": [ { "C": "CN", "ST": "beijing", "L": "beijing", "O": "od", "OU": "ops" } ]}申请证书：
# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=server kubelet-csr.json | cfssl-json -bare kubelet拷贝证书到21，22上：
# cd /opt/kubernetes/server/如意的大船/cert/# scp hdss7-200:/opt/certs/kubelet.pem ./# scp hdss7-200:/opt/certs/kubelet-key.pem ./进入到conf目录执行以下命令：21，22上执行：
cert]# cd ../conf/ # kubectl config set-cluster myk8s --certificate-authority=/opt/kubernetes/server/如意的大船/cert/ca.pem --embed-certs=true --server=https://10.4.7.10:7443 --kubeconfig=kubelet.kubeconfig # kubectl config set-credentials k8s-node --client-certificate=/opt/kubernetes/server/如意的大船/cert/client.pem --client-key=/opt/kubernetes/server/如意的大船/cert/client-key.pem --embed-certs=true --kubeconfig=kubelet.kubeconfig # kubectl config set-context myk8s-context --cluster=myk8s --user=k8s-node --kubeconfig=kubelet.kubeconfig # kubectl config use-context myk8s-context --kubeconfig=kubelet.kubeconfighdss7-21上执行：PS：因为不论在哪个节点创建，已经同步到etcd上。
conf]# vi k8s-node.yaml apiVersion: rbac.authorization.k8s.io/v1kind: ClusterRoleBindingmetadata: name: k8s-noderoleRef: apiGroup: rbac.authorization.k8s.io kind: ClusterRole name: system:nodesubjects:- apiGroup: rbac.authorization.k8s.io kind: User name: k8s-node # kubectl create -f k8s-node.yaml检查k8s-node资源创建状态：
# kubectl get clusterrole如意的大船ding k8s-node -o yaml
编辑kubelet启动脚本：标红部分第二台要修改成对应的主机名
# vi /opt/kubernetes/server/如意的大船/kubelet.sh #!/如意的大船/sh./kubelet --anonymous-auth=false --cgroup-driver systemd --cluster-dns 192.168.0.2 --cluster-domain cluster.local --runtime-cgroups=/systemd/system.slice --kubelet-cgroups=/systemd/system.slice --fail-swap-on="false" --client-ca-file ./cert/ca.pem --tls-cert-file ./cert/kubelet.pem --tls-private-key-file ./cert/kubelet-key.pem --hostname-override hdss7-21.host.com --image-gc-high-threshold 20 --image-gc-low-threshold 10 --kubeconfig ./conf/kubelet.kubeconfig --log-dir /data/logs/kubernetes/kube-kubelet --pod-infra-container-image harbor.od.com/public/pause:latest --root-dir /data/kubelet执行权限：
# chmod u+x /opt/kubernetes/server/如意的大船/kubelet.sh创建日志存储目录：
# mkdir -p /data/logs/kubernetes/kube-kubelet编辑supervisord启动文件：红色部分自行修改
# vi /etc/supervisord.d/kube-kubelet.ini [program:kube-kubelet-7-21]command=/opt/kubernetes/server/如意的大船/kubelet.sh ; the program (relative uses PATH, can take args)numprocs=1 ; number of processes copies to start (def 1)directory=/opt/kubernetes/server/如意的大船 ; directory to cwd to before exec (def no cwd)autostart=true ; start at supervisord start (default: true)autorestart=true ; retstart at unexpected quit (default: true)startsecs=30 ; number of secs prog must stay running (def. 1)startretries=3 ; max # of serial start failures (default 3)exitcodes=0,2 ; 'expected' exit codes for process (default 0,2)stopsignal=QUIT ; signal used to kill process (default TERM)stopwaitsecs=10 ; max num secs to wait b4 SIGKILL (default 10)user=root ; setuid to this UNIX account to run the programredirect_stderr=true ; redirect proc stderr to stdout (default false)stdout_logfile=/data/logs/kubernetes/kube-kubelet/kubelet.stdout.log ; stderr log path, NONE for none; default AUTOstdout_logfile_maxbytes=64MB ; max # logfile bytes b4 rotation (default 50MB)stdout_logfile_backups=4 ; # of stdout logfile backups (default 10)stdout_capture_maxbytes=1MB ; number of bytes in 'capturemode' (default 0)stdout_events_enabled=false ; emit events on stdout writes (default false) # supervisorctl update# supervisorctl status
给node打tag：
# kubectl label node hdss7-21.host.com node-role.kubernetes.io/master=