Kubernetes集群部署之五node节点部署

Node节点是Kubernetes集群中的工作负载节点.每个node都会被master分配一些工作负载,每个node节点都运行以下关键服务进程.
Kubelet :负责pod对应的容器的创建、启停等任务，同时与master节点密切协作，实现集群管理的基本功能.
Kube-proxy: 实现kubernetes service的通信与负载均衡机制的重要组件.

Docker Engine(docker): Docker引擎，负责本机的容器创建和管理工作.

部署kubelet:

1.二进制包准备 将软件包可执行文件从k8s-master复制到node节点中去。

[root@k8s-master ~]# cd /usr/local/src/kubernetes/server/bin
[root@k8s-master bin]# scp kubelet kube-proxy 10.200.3.106:/opt/kubernetes/bin/
[root@k8s-master bin]# scp kubelet kube-proxy 10.200.3.107:/opt/kubernetes/bin/

2.创建角色绑定

[root@k8s-master ~]# cd /usr/local/src/ssl/
[root@k8s-master ssl]#  kubectl create clusterrolebinding kubelet-bootstrap 
  --clusterrole=system:node-bootstrapper 
  --user=kubelet-bootstrap

clusterrolebinding "kubelet-bootstrap" createdclusterrolebinding.rbac.authorization.k8s.io "kubelet-bootstrap" created

3.创建 kubelet bootstrap.kubeconfig 文件 设置集群参数

[root@k8s-master ssl]#  kubectl config set-cluster kubernetes 
   --certificate-authority=/opt/kubernetes/ssl/ca.pem 
   --embed-certs=true 
   --server=https://10.200.3.105:6443 
   --kubeconfig=bootstrap.kubeconfig

Cluster "kubernetes" set.

4.设置客户端认证参数,token值为之前生成的.

[root@k8s-master ssl]# kubectl config set-credentials kubelet-bootstrap 
   --token=10a89e49bc403bce8fb134e5a2ae82f1 
   --kubeconfig=bootstrap.kubeconfig

User "kubelet-bootstrap" set.

5.设置上下文参数

[root@k8s-master ssl]# kubectl config set-context default 
   --cluster=kubernetes 
   --user=kubelet-bootstrap 
   --kubeconfig=bootstrap.kubeconfig
      
Context "default" created.

6.选择默认上下文并向node节点分发在master端生成的bootstrap.kubeconfig文件.

[root@k8s-master ssl]# kubectl config use-context default --kubeconfig=bootstrap.kubeconfig
Switched to context "default".

[root@k8s-master ssl]# cp bootstrap.kubeconfig /opt/kubernetes/cfg
[root@k8s-master ssl]# scp bootstrap.kubeconfig 10.200.3.106:/opt/kubernetes/cfg
[root@k8s-master ssl]# scp bootstrap.kubeconfig 10.200.3.107:/opt/kubernetes/cfg

部署kubelet(node节点操作).

1.设置CNI支持.

[root@k8s-node-1 ~]# mkdir -p /etc/cni/net.d
[root@k8s-node-1 ~]# cat > /etc/cni/net.d/10-default.conf <<EOF
{
        "name": "flannel",
        "type": "flannel",
        "delegate": {
            "bridge": "docker0",
            "isDefaultGateway": true,
            "mtu": 1400
        }
}

EOF

2.创建kubelet目录

[root@k8s-node-1 ~]# mkdir /var/lib/kubelet

3.创建kubelet服务配置

[root@k8s-node-1 ~]# cat > /usr/lib/systemd/system/kubelet.service <<EOF
[Unit]
Description=Kubernetes Kubelet
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=docker.service
Requires=docker.service

[Service]
WorkingDirectory=/var/lib/kubelet
ExecStart=/opt/kubernetes/bin/kubelet 
  --address=10.200.3.106 
  --hostname-override=10.200.3.106 
  --pod-infra-container-image=mirrorgooglecontainers/pause-amd64:3.0 
  --experimental-bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig 
  --kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig 
  --cert-dir=/opt/kubernetes/ssl 
  --network-plugin=cni 
  --cni-conf-dir=/etc/cni/net.d 
  --cni-bin-dir=/opt/kubernetes/bin/cni 
  --cluster-dns=10.1.0.2 
  --cluster-domain=cluster.local. 
  --hairpin-mode hairpin-veth 
  --allow-privileged=true 
  --fail-swap-on=false 
  --logtostderr=true 
  --v=2 
  --logtostderr=false 
  --log-dir=/opt/kubernetes/log
Restart=on-failure
RestartSec=5

EOF

4.启动Kubelet

[root@k8s-node-1 ~]# systemctl daemon-reload
[root@k8s-node-1 ~]# systemctl enable kubelet
[root@k8s-node-1 ~]# systemctl start kubelet
[root@k8s-node-1 ~]# systemctl status kubelet

5.查看csr请求 注意是在k8s-maste上执行

[root@k8s-master ssl]# kubectl get csr
NAME                                                   AGE       REQUESTOR           CONDITION
node-csr-exRV4L4JbdyoO62eNEcTnSK7ehYji_47xhkU7e5-L5c   43s       kubelet-bootstrap   Pending

6.批准kubelet 的 TLS 证书请求

[root@k8s-master ssl]# kubectl get csr|grep 'Pending' | awk 'NR>0{print $1}'| xargs kubectl certificate approve
certificatesigningrequest.certificates.k8s.io "node-csr-exRV4L4JbdyoO62eNEcTnSK7ehYji_47xhkU7e5-L5c" approved

执行完毕后，查看节点状态如果是Ready的状态就说明一切正常.

[root@k8s-master ~]# kubectl get node
NAME           STATUS    ROLES     AGE       VERSION
10.200.3.106   Ready     <none>    1d        v1.10.1

部署Kubernetes Proxy

1.配置kube-proxy使用LVS

[root@v0-k8s-node-1]# yum install -y ipvsadm ipset conntrack

2.创建 kube-proxy 证书请求

[root@k8s-master ~]# cd /usr/local/src/ssl/
[root@k8s-master ssl]# cat > kube-proxy-csr.json <<EOF

{
  "CN": "system:kube-proxy",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ]
}

EOF

3.生成证书，并分发至node节点.

[root@k8s-master ssl]#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
   
[root@k8s-master ssl]# cp kube-proxy*.pem /opt/kubernetes/ssl/
[root@k8s-master ssl]# scp kube-proxy*.pem 10.200.3.106:/opt/kubernetes/ssl/
[root@k8s-master ssl]# scp kube-proxy*.pem 10.200.3.107:/opt/kubernetes/ssl/

4.创建kube-proxy配置文件

[root@k8s-master ssl]# kubectl config set-cluster kubernetes 
   --certificate-authority=/opt/kubernetes/ssl/ca.pem 
   --embed-certs=true 
   --server=https://10.200.3.105:6443 
   --kubeconfig=kube-proxy.kubeconfig
   
Cluster "kubernetes" set.

[root@k8s-master ssl]#kubectl config set-credentials kube-proxy 
   --client-certificate=/opt/kubernetes/ssl/kube-proxy.pem 
   --client-key=/opt/kubernetes/ssl/kube-proxy-key.pem 
   --embed-certs=true 
   --kubeconfig=kube-proxy.kubeconfig

User "kube-proxy" set.

[root@k8s-master ssl]#kubectl config set-context default 
   --cluster=kubernetes 
   --user=kube-proxy 
   --kubeconfig=kube-proxy.kubeconfig
Context "default" created.

[root@k8s-master ssl]# kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
Switched to context "default".

6.分发kubeconfig配置文件到各节点.

[root@k8s-master ssl]# cp kube-proxy.kubeconfig /opt/kubernetes/cfg/
[root@k8s-master ssl]# scp kube-proxy.kubeconfig 10.200.3.106:/opt/kubernetes/cfg/
[root@k8s-master ssl]# scp kube-proxy.kubeconfig 10.200.3.107:/opt/kubernetes/cfg/

7.创建kube-proxy服务配置

[root@k8s-node-1 ~]# mkdir /var/lib/kube-proxy
[root@k8s-node-1 ~]# cat > /usr/lib/systemd/system/kube-proxy.service <<EOF

[Unit]
Description=Kubernetes Kube-Proxy Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target

[Service]
WorkingDirectory=/var/lib/kube-proxy
ExecStart=/opt/kubernetes/bin/kube-proxy 
  --bind-address=10.200.3.106 
  --hostname-override=10.200.3.106 
  --kubeconfig=/opt/kubernetes/cfg/kube-proxy.kubeconfig 
--masquerade-all 
  --feature-gates=SupportIPVSProxyMode=true 
  --proxy-mode=ipvs 
  --ipvs-min-sync-period=5s 
  --ipvs-sync-period=5s 
  --ipvs-scheduler=rr 
  --logtostderr=true 
  --v=2 
  --logtostderr=false 
  --log-dir=/opt/kubernetes/log

Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

EOF

8.启动Kubernetes Proxy

[root@k8s-node-1 ~]# systemctl daemon-reload
[root@k8s-node-1 ~]# systemctl enable kube-proxy
[root@k8s-node-1 ~]# systemctl start kube-proxy
[root@k8s-node-1 ~]# systemctl status kube-proxy

9.检查LVS状态

[root@k8s-node-1 ~]# ipvsadm -L -n
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  10.1.0.1:443 rr persistent 10800
  -> 10.200.3.105:6443            Masq    1      0          0         
[root@k8s-node-1 ~]# 

如果你在两台实验机器都安装了kubelet和proxy服务，使用下面的命令可以检查状态：

[root@k8s-master ~]# kubectl get nodes

NAME           STATUS    ROLES     AGE       VERSION
10.200.3.106   Ready     <none>    3h        v1.10.1
10.200.3.107   Ready     <none>    29m       v1.10.1

参考文档：https://github.com/unixhot/salt-kubernetes/blob/master/docs/node.md