全新一台node节点加入到集群中

前言

基于前面的所有文章完成后，这里介绍一下如何添加一个全新的节点；

对新节点做解析

方法一 hosts 文件解析

如果使用的是 hosts 文件解析，则需要在所有节点的 hsots 文件添加下面内容：

10.0.20.15 node05 node05.k8s.com

方法二 bind 解析

如果使用的时候内部bind 做DNS解析，则只需要添加一条A记录即可

node05  IN  A   10.0.20.15

重载bind配置文件

rndc reload

测试

在 node01 机器上测试

[root@node01 work]# ping -c 1 node05
PING node05.k8s.com (10.0.20.15) 56(84) bytes of data.
64 bytes from 10.0.20.15 (10.0.20.15): icmp_seq=1 ttl=64 time=0.122 ms

--- node05.k8s.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.122/0.122/0.122/0.000 ms
[root@node01 work]# ping -c 1 node05.k8s.com
PING node05.k8s.com (10.0.20.15) 56(84) bytes of data.
64 bytes from 10.0.20.15 (10.0.20.15): icmp_seq=1 ttl=64 time=0.121 ms

--- node05.k8s.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.121/0.121/0.121/0.000 ms

分发密钥对

为了方便推送文件，这一步可做可不做

ssh-copy-id -i ~/.ssh/id_rsa.pub node05

推送 CA 证书

ssh node05 "mkdir -p /etc/kubernetes/cert"
scp ca*.pem ca-config.json node05:/etc/kubernetes/cert

flanneld 部署

下面所有步骤都在 node01 上执行

推送flanneld二进制命令

scp flannel/{flanneld,mk-docker-opts.sh} node05:/opt/k8s/bin/

推送flanneld秘钥

ssh node05 "mkdir -p /etc/flanneld/cert"
scp flanneld*.pem node05:/etc/flanneld/cert

推送flanneld启动文件

scp flanneld.service node05:/etc/systemd/system/

启动flanneld

ssh node05 "systemctl daemon-reload && systemctl enable flanneld && systemctl restart flanneld"
ssh node05 "systemctl status flanneld|grep Active"

查看flanneld网络

ssh node05 "/usr/sbin/ip addr show flannel.1|grep -w inet"

查看etcd中网络数据

查看一下etcd中CIDR分配的数量是否添加

source /opt/k8s/bin/environment.sh
etcdctl \
  --endpoints=${ETCD_ENDPOINTS} \
  --ca-file=/etc/kubernetes/cert/ca.pem \
  --cert-file=/etc/flanneld/cert/flanneld.pem \
  --key-file=/etc/flanneld/cert/flanneld-key.pem \
  get ${FLANNEL_ETCD_PREFIX}/subnets/172.30.80.0-21

查看输出结果：

[root@node01 work]# etcdctl \
>   --endpoints=${ETCD_ENDPOINTS} \
>   --ca-file=/etc/kubernetes/cert/ca.pem \
>   --cert-file=/etc/flanneld/cert/flanneld.pem \
>   --key-file=/etc/flanneld/cert/flanneld-key.pem \
>   ls ${FLANNEL_ETCD_PREFIX}/subnets
/kubernetes/network/subnets/172.30.80.0-21
/kubernetes/network/subnets/172.30.48.0-21
/kubernetes/network/subnets/172.30.216.0-21
/kubernetes/network/subnets/172.30.224.0-21
/kubernetes/network/subnets/172.30.160.0-21

从上面输出看出，新节点的flanneld已经正常

docker 安装配置

这里直接在 node05 节点上操作

安装

yum install docker-ce-18.09.6 -y

创建配置文件

mkdir -p /etc/docker/
cat > /etc/docker/daemon.json <

修改Docker启动参数

vim /usr/lib/systemd/system/docker.service
EnvironmentFile=-/run/flannel/docker
ExecStart=/usr/bin/dockerd $DOCKER_NETWORK_OPTIONS -H fd:// --containerd=/run/containerd/containerd.sock

启动查看

[root@localhost ~]# vim /usr/lib/systemd/system/docker.service 
[root@localhost ~]# systemctl enable docker
Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.
[root@localhost ~]# systemctl start docker

查看docker0网桥是否是 flanneld 网络的网关

[root@localhost ~]# ip addr show flannel.1 && /usr/sbin/ip addr show docker0
5: flannel.1:  mtu 1450 qdisc noqueue state UNKNOWN group default 
    link/ether fe:64:95:d1:b5:7c brd ff:ff:ff:ff:ff:ff
    inet 172.30.216.0/32 scope global flannel.1
       valid_lft forever preferred_lft forever
6: docker0:  mtu 1500 qdisc noqueue state DOWN group default 
    link/ether 02:42:79:3b:10:f3 brd ff:ff:ff:ff:ff:ff
    inet 172.30.216.1/21 brd 172.30.223.255 scope global docker0
       valid_lft forever preferred_lft forever

kubelet 安装

这里在 node01 上操作

推送 kubelet 二进制文件

scp kubernetes/server/bin/kubelet node05:/opt/k8s/bin/

创建 kubelet bootstrap kubeconfig 文件

export BOOTSTRAP_TOKEN=$(kubeadm token create \
  --description kubelet-bootstrap-token \
  --groups system:bootstrappers:node05 \
  --kubeconfig ~/.kube/config)
# 设置集群参数
kubectl config set-cluster kubernetes \
  --certificate-authority=/etc/kubernetes/cert/ca.pem \
  --embed-certs=true \
  --server=https://vip.k8s.com:8443 \
  --kubeconfig=kubelet-bootstrap-node05.kubeconfig
# 设置客户端认证参数
kubectl config set-credentials kubelet-bootstrap \
  --token=${BOOTSTRAP_TOKEN} \
  --kubeconfig=kubelet-bootstrap-node05.kubeconfig
# 设置上下文参数
kubectl config set-context default \
  --cluster=kubernetes \
  --user=kubelet-bootstrap \
  --kubeconfig=kubelet-bootstrap-node05.kubeconfig
# 设置默认上下文
kubectl config use-context default --kubeconfig=kubelet-bootstrap-node05.kubeconfig

分发 bootstrap kubeconfig 文件到所有 worker 节点

scp kubelet-bootstrap-node05.kubeconfig root@node05:/etc/kubernetes/kubelet-bootstrap.kubeconfig

查看kubeadm为新节点创建的token

[root@node01 work]# kubeadm token list --kubeconfig ~/.kube/config
TOKEN                     TTL       EXPIRES                     USAGES                   DESCRIPTION               EXTRA GROUPS
cu4q2e.ogvim78s3p252ysg   7h        2019-12-06T17:44:24+08:00   authentication,signing   kubelet-bootstrap-token   system:bootstrappers:node03
nrypmb.35fyygbwr9failr5   7h        2019-12-06T17:44:23+08:00   authentication,signing   kubelet-bootstrap-token   system:bootstrappers:node01
r5luwb.6x6c5lnit5utyotz   7h        2019-12-06T17:44:23+08:00   authentication,signing   kubelet-bootstrap-token   system:bootstrappers:node02
# 下面多了一条node05
ss66d3.yse8ia5bt1s06jmg   23h       2019-12-07T10:01:58+08:00   authentication,signing   kubelet-bootstrap-token   system:bootstrappers:node05
sx8n4m.vlltkkv8m23ogxg9   7h        2019-12-06T17:44:24+08:00   authentication,signing   kubelet-bootstrap-token   system:bootstrappers:node04

查看 token 关联的 Secret

[root@node01 work]# kubectl get secrets  -n kube-system|grep bootstrap-token
bootstrap-token-cu4q2e                           bootstrap.kubernetes.io/token         7      16h
bootstrap-token-nrypmb                           bootstrap.kubernetes.io/token         7      16h
bootstrap-token-r5luwb                           bootstrap.kubernetes.io/token         7      16h
# 根据上面查看的token，下面这条是新添加的
bootstrap-token-ss66d3                           bootstrap.kubernetes.io/token         7      99s
bootstrap-token-sx8n4m                           bootstrap.kubernetes.io/token         7      16h

创建和分发kubelet参数配置

cd /opt/k8s/work
sed -e "s/##NODE_IP##/10.0.20.15/" kubelet-config.yaml.template > kubelet-config-10.0.20.15.yaml.template
scp kubelet-config-10.0.20.15.yaml.template root@node05:/etc/kubernetes/kubelet-config.yaml

创建和分发kubelet启动文件

cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
sed -e "s/##NODE_NAME##/node05/" kubelet.service.template > kubelet-node05.service
scp kubelet-node05.service root@node05:/etc/systemd/system/kubelet.service

启动 kubelet 服务

cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
ssh root@node05 "mkdir -p ${K8S_DIR}/kubelet/kubelet-plugins/volume/exec/"
ssh root@node05 "/usr/sbin/swapoff -a"
ssh root@node05 "systemctl daemon-reload && systemctl enable kubelet && systemctl restart kubelet"

手动approve server cert csr

稍等片刻后，需要手动通过证书请求
基于安全考虑，CSR approving controllers不会自动approve kubelet server证书签名请求，需要手动approve

kubectl get csr | grep Pending | awk '{print $1}' | xargs kubectl certificate approve

查看新节点

此时再次使用 查看节点的命令时，发现已经添加成功

[root@node01 work]# kubectl get nodes
NAME     STATUS   ROLES    AGE   VERSION
node01   Ready       16h   v1.15.6
node02   Ready       16h   v1.15.6
node03   Ready       16h   v1.15.6
node04   Ready       16h   v1.15.6
node05   Ready       74s   v1.15.6   # 这里显示正常

kube-proxy 安装

此处均在 node01 上执行

推送 kube-proxy 二进制启动文件

cd /opt/k8s/work/
scp kubernetes/server/bin/kube-proxy node05:/opt/k8s/bin/

分发 kubeconfig 文件

cd /opt/k8s/work/
scp kube-proxy.kubeconfig root@node05:/etc/kubernetes/

分发和创建kube-proxy配置文件

cd /opt/k8s/work/
sed -e "s/##NODE_NAME##/node05/" -e "s/##NODE_IP##/10.0.20.15/" kube-proxy-config.yaml.template > kube-proxy-config-node05.yaml.template
scp kube-proxy-config-node05.yaml.template root@node05:/etc/kubernetes/kube-proxy-config.yaml

分发 kube-proxy systemd unit 文件

scp kube-proxy.service root@node05:/etc/systemd/system/

启动 kube-proxy 服务

cd /opt/k8s/work
source /opt/k8s/bin/environment.sh
ssh root@node05 "mkdir -p ${K8S_DIR}/kube-proxy"
ssh root@node05 "modprobe ip_vs_rr"
ssh root@node05 "systemctl daemon-reload && systemctl enable kube-proxy && systemctl restart kube-proxy"

检查启动结果

ssh root@node05 "systemctl status kube-proxy|grep Active"
ssh root@node05 "netstat -lnpt|grep kube-prox"

查看ipvs路由规则

ssh root@node05 "/usr/sbin/ipvsadm -ln"

输出：

[root@node01 work]# ssh root@node05 "/usr/sbin/ipvsadm -ln"
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  10.254.0.1:443 rr
  -> 10.0.20.11:6443              Masq    1      0          0         
  -> 10.0.20.12:6443              Masq    1      0          0         
  -> 10.0.20.13:6443              Masq    1      0          0         
TCP  10.254.0.2:53 rr
  -> 172.30.48.2:53               Masq    1      0          0         
  -> 172.30.160.2:53              Masq    1      0          0         
TCP  10.254.0.2:9153 rr
  -> 172.30.48.2:9153             Masq    1      0          0         
  -> 172.30.160.2:9153            Masq    1      0          0         
UDP  10.254.0.2:53 rr
  -> 172.30.48.2:53               Masq    1      0          0         
  -> 172.30.160.2:53              Masq    1      0          0 

至此，全新的node节点加入集群操作完成。

查看当前集群 nodes

[root@node01 work]# kubectl get nodes -o wide
NAME     STATUS   ROLES    AGE   VERSION   INTERNAL-IP   EXTERNAL-IP   OS-IMAGE                KERNEL-VERSION              CONTAINER-RUNTIME
node01   Ready       16h   v1.15.6   10.0.20.11            CentOS Linux 7 (Core)   5.4.1-1.el7.elrepo.x86_64   docker://18.9.6
node02   Ready       16h   v1.15.6   10.0.20.12            CentOS Linux 7 (Core)   5.4.1-1.el7.elrepo.x86_64   docker://18.9.6
node03   Ready       16h   v1.15.6   10.0.20.13            CentOS Linux 7 (Core)   5.4.1-1.el7.elrepo.x86_64   docker://18.9.6
node04   Ready       16h   v1.15.6   10.0.20.14            CentOS Linux 7 (Core)   5.4.1-1.el7.elrepo.x86_64   docker://18.9.6
node05   Ready       12m   v1.15.6   10.0.20.15            CentOS Linux 7 (Core)   5.4.1-1.el7.elrepo.x86_64   docker://18.9.6