kubernetes(K8S)学习（七）：K8S之系统核心组件

K8s系统核心组件

1.1 Master和Node

官网 ：https://kubernetes.io/zh/docs/concepts/architecture/master-node-communication/

K8S集群中的控制节点，负责整个集群的管理和控制，可以做成高可用，防止一台Master打竞技或者不可用。
其中有一些关键的组件：比如API Server，Controller Manager，Scheduler等

Node

Node会被Master分配一些工作负载，当某个Node不可用时，会将工作负载转移到其他Node节点上。
Node上有一些关键的进程：kubelet，kube-proxy，docker等

查看集群中的Node

kubectl get nodes
kubectl describe node node-name

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1.2 kubeadm

1.2.1 kubeadm init

[root@m ~]# kubeadm init --kubernetes-version=1.14.0 \
>     --apiserver-advertise-address=192.168.116.170 \
>     --pod-network-cidr=10.244.0.0/16
[init] Using Kubernetes version: v1.14.0
[preflight] Running pre-flight checks
[preflight] Pulling images required for setting up a Kubernetes cluster
[preflight] This might take a minute or two, depending on the speed of your internet connection
[preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
[kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[kubelet-start] Activating the kubelet service
[certs] Using certificateDir folder "/etc/kubernetes/pki"
[certs] Generating "ca" certificate and key
[certs] Generating "apiserver" certificate and key
[certs] apiserver serving cert is signed for DNS names [m kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.116.170]
[certs] Generating "apiserver-kubelet-client" certificate and key
[certs] Generating "front-proxy-ca" certificate and key
[certs] Generating "front-proxy-client" certificate and key
[certs] Generating "etcd/ca" certificate and key
[certs] Generating "etcd/healthcheck-client" certificate and key
[certs] Generating "etcd/server" certificate and key
[certs] etcd/server serving cert is signed for DNS names [m localhost] and IPs [192.168.116.170 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [m localhost] and IPs [192.168.116.170 127.0.0.1 ::1]
[certs] Generating "apiserver-etcd-client" certificate and key
[certs] Generating "sa" key and public key
[kubeconfig] Using kubeconfig folder "/etc/kubernetes"
[kubeconfig] Writing "admin.conf" kubeconfig file
[kubeconfig] Writing "kubelet.conf" kubeconfig file
[kubeconfig] Writing "controller-manager.conf" kubeconfig file
[kubeconfig] Writing "scheduler.conf" kubeconfig file
[control-plane] Using manifest folder "/etc/kubernetes/manifests"
[control-plane] Creating static Pod manifest for "kube-apiserver"
[control-plane] Creating static Pod manifest for "kube-controller-manager"
[control-plane] Creating static Pod manifest for "kube-scheduler"
[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
[wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests"