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