搭建k8s高可用集群 - 二进制方式

实践环境准备

服务器说明

我这里使用的是五台CentOS-7.7的虚拟机,具体信息如下表:

系统版本 IP地址 节点角色 CPU Memory Hostname
CentOS-7.7 192.168.243.143 master >=2 >=2G m1
CentOS-7.7 192.168.243.144 master >=2 >=2G m2
CentOS-7.7 192.168.243.145 master >=2 >=2G m3
CentOS-7.7 192.168.243.146 worker >=2 >=2G n1
CentOS-7.7 192.168.243.147 worker >=2 >=2G n2

这五台机器均需事先安装好Docker,由于安装过程比较简单这里不进行介绍,可以参考官方文档:

软件版本说明:

  • k8s:1.19.0
  • etcd:3.4.13
  • coredns:1.7.0
  • pause:3.2
  • calico:3.16.0
  • cfssl:1.2.0
  • kubernetes dashboard:2.0.3

以下是搭建k8s集群过程中ip、端口等网络相关配置的说明,后续将不再重复解释:

# 3个master节点的ip
192.168.243.143
192.168.243.144
192.168.243.145

# 2个worker节点的ip
192.168.243.146
192.168.243.147

# 3个master节点的hostname
m1、m2、m3

# api-server的高可用虚拟ip(keepalived会用到,可自定义)
192.168.243.101

# keepalived用到的网卡接口名,一般是eth0,可执行ip a命令查看
ens32

# kubernetes服务ip网段(可自定义)
10.255.0.0/16

# kubernetes的api-server服务的ip,一般是cidr的第一个(可自定义)
10.255.0.1

# dns服务的ip地址,一般是cidr的第二个(可自定义)
10.255.0.2

# pod网段(可自定义)
172.23.0.0/16

# NodePort的取值范围(可自定义)
8400-8900

系统设置(所有节点)

1、主机名必须每个节点都不一样,并且保证所有点之间可以通过hostname互相访问。设置hostname:

# 查看主机名
$ hostname
# 修改主机名
$ hostnamectl set-hostname <your_hostname>

配置host,使所有节点之间可以通过hostname互相访问:

$ vim /etc/hosts
192.168.243.143 m1
192.168.243.144 m2
192.168.243.145 m3
192.168.243.146 n1
192.168.243.147 n2

2、安装依赖包:

# 更新yum
$ yum update -y

# 安装依赖包
$ yum install -y conntrack ipvsadm ipset jq sysstat curl wget iptables libseccomp

3、关闭防火墙、swap,重置iptables:

# 关闭防火墙
$ systemctl stop firewalld && systemctl disable firewalld

# 重置iptables
$ iptables -F && iptables -X && iptables -F -t nat && iptables -X -t nat && iptables -P FORWARD ACCEPT

# 关闭swap
$ swapoff -a
$ sed -i '/swap/s/^\(.*\)$/#\1/g' /etc/fstab

# 关闭selinux
$ setenforce 0

# 关闭dnsmasq(否则可能导致docker容器无法解析域名)
$ service dnsmasq stop && systemctl disable dnsmasq

# 重启docker服务
$ systemctl restart docker

4、系统参数设置:

# 制作配置文件
$ cat > /etc/sysctl.d/kubernetes.conf <<EOF
net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-ip6tables=1
net.ipv4.ip_forward=1
vm.swappiness=0
vm.overcommit_memory=1
vm.panic_on_oom=0
fs.inotify.max_user_watches=89100
EOF

# 生效文件
$ sysctl -p /etc/sysctl.d/kubernetes.conf

准备二进制文件(所有节点)

配置免密登录

由于二进制的搭建方式需要各个节点具备k8s组件的二进制可执行文件,所以我们得将准备好的二进制文件copy到各个节点上。为了方便文件的copy,我们可以选择一个中转节点(随便一个节点),配置好跟其他所有节点的免密登录,这样在copy的时候就不需要反复输入密码了。

我这里选择m1作为中转节点,首先在m1节点上创建一对密钥:

[root@m1 ~]# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa): 
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:9CVdxUGLSaZHMwzbOs+aF/ibxNpsUaaY4LVJtC3DJiU root@m1
The key's randomart image is:
+---[RSA 2048]----+
|           .o*o=o|
|         E +Bo= o|
|        . *o== . |
|       . + @o. o |
|        S BoO +  |
|         . *=+   |
|            .=o  |
|            B+.  |
|           +o=.  |
+----[SHA256]-----+
[root@m1 ~]# 

查看公钥的内容:

[root@m1 ~]# cat ~/.ssh/id_rsa.pub
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDF99/mk7syG+OjK5gFFKLZDpMWcF3BEF1Gaa8d8xNIMKt2qGgxyYOC7EiGcxanKw10MQCoNbiAG1UTd0/wgp/UcPizvJ5AKdTFImzXwRdXVbMYkjgY2vMYzpe8JZ5JHODggQuGEtSE9Q/RoCf29W2fIoOKTKaC2DNyiKPZZ+zLjzQr8sJC3BRb1Tk4p8cEnTnMgoFwMTZD8AYMNHwhBeo5NXZSE8zyJiWCqQQkD8n31wQxVgSL9m3rD/1wnsBERuq3cf7LQMiBTxmt1EyqzqM4S1I2WEfJkT0nJZeY+zbHqSJq2LbXmCmWUg5LmyxaE9Ksx4LDIl7gtVXe99+E1NLd root@m1
[root@m1 ~]# 

然后把id_rsa.pub文件中的内容copy到其他机器的授权文件中,在其他节点执行下面命令(这里的公钥替换成你生成的公钥):

$ echo "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDF99/mk7syG+OjK5gFFKLZDpMWcF3BEF1Gaa8d8xNIMKt2qGgxyYOC7EiGcxanKw10MQCoNbiAG1UTd0/wgp/UcPizvJ5AKdTFImzXwRdXVbMYkjgY2vMYzpe8JZ5JHODggQuGEtSE9Q/RoCf29W2fIoOKTKaC2DNyiKPZZ+zLjzQr8sJC3BRb1Tk4p8cEnTnMgoFwMTZD8AYMNHwhBeo5NXZSE8zyJiWCqQQkD8n31wQxVgSL9m3rD/1wnsBERuq3cf7LQMiBTxmt1EyqzqM4S1I2WEfJkT0nJZeY+zbHqSJq2LbXmCmWUg5LmyxaE9Ksx4LDIl7gtVXe99+E1NLd root@m1" >> ~/.ssh/authorized_keys

测试一下能否免密登录,可以看到我这里登录m2节点不需要输入密码:

[root@m1 ~]# ssh m2
Last login: Fri Sep  4 15:55:59 2020 from m1
[root@m2 ~]# 

下载二进制文件

下载Kubernetes

我们首先下载k8s的二进制文件,k8s的官方下载地址如下:

我这里下载的是1.19.0版本,注意下载链接是在CHANGELOG/CHANGELOG-1.19.md里面:

image.png

只需要在“Server Binaries”一栏选择对应的平台架构下载即可,因为Server的压缩包里已经包含了Node和Client的二进制文件:


image.png

复制下载链接,到系统上下载并解压:

[root@m1 ~]# cd /usr/local/src
[root@m1 /usr/local/src]# wget https://dl.k8s.io/v1.19.0/kubernetes-server-linux-amd64.tar.gz  # 下载
[root@m1 /usr/local/src]# tar -zxvf kubernetes-server-linux-amd64.tar.gz  # 解压

k8s的二进制文件都存放在kubernetes/server/bin/目录下:

[root@m1 /usr/local/src]# ls kubernetes/server/bin/
apiextensions-apiserver  kube-apiserver             kube-controller-manager             kubectl     kube-proxy.docker_tag  kube-scheduler.docker_tag
kubeadm                  kube-apiserver.docker_tag  kube-controller-manager.docker_tag  kubelet     kube-proxy.tar         kube-scheduler.tar
kube-aggregator          kube-apiserver.tar         kube-controller-manager.tar         kube-proxy  kube-scheduler         mounter
[root@m1 /usr/local/src]# 

为了后面copy文件方便,我们需要整理一下文件,将不同节点所需的二进制文件统一放在相同的目录下。具体步骤如下:

[root@m1 /usr/local/src]# mkdir -p k8s-master k8s-worker
[root@m1 /usr/local/src]# cd kubernetes/server/bin/
[root@m1 /usr/local/src/kubernetes/server/bin]# for i in kubeadm kube-apiserver kube-controller-manager kubectl kube-scheduler;do cp $i /usr/local/src/k8s-master/; done
[root@m1 /usr/local/src/kubernetes/server/bin]# for i in kubelet kube-proxy;do cp $i /usr/local/src/k8s-worker/; done
[root@m1 /usr/local/src/kubernetes/server/bin]# 

整理后的文件都被放在了相应的目录下,k8s-master目录存放master所需的二进制文件,k8s-worker目录则存放了worker节点所需的文件:

[root@m1 /usr/local/src/kubernetes/server/bin]# cd /usr/local/src
[root@m1 /usr/local/src]# ls k8s-master/
kubeadm  kube-apiserver  kube-controller-manager  kubectl  kube-scheduler
[root@m1 /usr/local/src]# ls k8s-worker/
kubelet  kube-proxy
[root@m1 /usr/local/src]# 

下载etcd

k8s依赖于etcd做分布式存储,所以接下来我们还需要下载etcd,官方下载地址如下:

我这里下载的是3.4.13版本:

image.png

同样,复制下载链接到系统上使用wget命令进行下载并解压:

[root@m1 /usr/local/src]# wget https://github.com/etcd-io/etcd/releases/download/v3.4.13/etcd-v3.4.13-linux-amd64.tar.gz
[root@m1 /usr/local/src]# mkdir etcd && tar -zxvf etcd-v3.4.13-linux-amd64.tar.gz -C etcd --strip-components 1
[root@m1 /usr/local/src]# ls etcd
Documentation  etcd  etcdctl  README-etcdctl.md  README.md  READMEv2-etcdctl.md
[root@m1 /usr/local/src]# 

将etcd的二进制文件拷贝到k8s-master目录下:

[root@m1 /usr/local/src]# cd etcd
[root@m1 /usr/local/src/etcd]# for i in etcd etcdctl;do cp $i /usr/local/src/k8s-master/; done
[root@m1 /usr/local/src/etcd]# ls ../k8s-master/
etcd  etcdctl  kubeadm  kube-apiserver  kube-controller-manager  kubectl  kube-scheduler
[root@m1 /usr/local/src/etcd]# 

分发文件并设置好PATH

在所有节点上创建/opt/kubernetes/bin目录:

$ mkdir -p /opt/kubernetes/bin

将二进制文件分发到相应的节点上:

[root@m1 /usr/local/src]# for i in m1 m2 m3; do scp k8s-master/* $i:/opt/kubernetes/bin/; done
[root@m1 /usr/local/src]# for i in n1 n2; do scp k8s-worker/* $i:/opt/kubernetes/bin/; done

给每个节点设置PATH环境变量:

[root@m1 /usr/local/src]# for i in m1 m2 m3 n1 n2; do ssh $i "echo 'PATH=/opt/kubernetes/bin:$PATH' >> ~/.bashrc"; done

高可用集群部署

生成CA证书(任意节点)

安装cfssl

cfssl是非常好用的CA工具,我们用它来生成证书和秘钥文件。安装过程比较简单,我这里选择在m1节点上安装。首先下载cfssl的二进制文件:

[root@m1 ~]# mkdir -p ~/bin
[root@m1 ~]# wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64 -O ~/bin/cfssl
[root@m1 ~]# wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64 -O ~/bin/cfssljson

将这两个文件授予可执行的权限:

[root@m1 ~]# chmod +x ~/bin/cfssl ~/bin/cfssljson

设置一下PATH环境变量:

[root@m1 ~]# vim ~/.bashrc
PATH=~/bin:$PATH
[root@m1 ~]# source ~/.bashrc

验证一下是否能正常执行:

[root@m1 ~]# cfssl version
Version: 1.2.0
Revision: dev
Runtime: go1.6
[root@m1 ~]# 

生成根证书

根证书是集群所有节点共享的,所以只需要创建一个 CA 证书,后续创建的所有证书都由它签名。首先创建一个ca-csr.json文件,内容如下:

{
  "CN": "kubernetes",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "seven"
    }
  ]
}

执行以下命令,生成证书和私钥

[root@m1 ~]# cfssl gencert -initca ca-csr.json | cfssljson -bare ca

生成完成后会有以下文件(我们最终想要的就是ca-key.pemca.pem,一个秘钥,一个证书):

[root@m1 ~]# ls *.pem
ca-key.pem  ca.pem
[root@m1 ~]# 

将这两个文件分发到每个master节点上:

[root@m1 ~]# for i in m1 m2 m3; do ssh $i "mkdir -p /etc/kubernetes/pki/"; done
[root@m1 ~]# for i in m1 m2 m3; do scp *.pem $i:/etc/kubernetes/pki/; done

部署etcd集群(master节点)

生成证书和私钥

接下来我们需要生成etcd节点使用的证书和私钥,创建ca-config.json文件,内容如下:

{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
        "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ],
        "expiry": "87600h"
      }
    }
  }
}

然后创建etcd-csr.json文件,内容如下:

{
  "CN": "etcd",
  "hosts": [
    "127.0.0.1",
    "192.168.243.143",
    "192.168.243.144",
    "192.168.243.145"
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "seven"
    }
  ]
}
  • hosts里的ip是master节点的ip

有了以上两个文件以后就可以使用如下命令生成etcd的证书和私钥:

[root@m1 ~]# cfssl gencert -ca=ca.pem \
    -ca-key=ca-key.pem \
    -config=ca-config.json \
    -profile=kubernetes etcd-csr.json | cfssljson -bare etcd
[root@m1 ~]# ls etcd*.pem  # 执行成功会生成两个文件
etcd-key.pem  etcd.pem
[root@m1 ~]# 

然后将这两个文件分发到每个etcd节点:

[root@m1 ~]# for i in m1 m2 m3; do scp etcd*.pem $i:/etc/kubernetes/pki/; done

创建service文件

创建etcd.service文件,用于后续可以通过systemctl命令去启动、停止及重启etcd服务,内容如下:

[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target
Documentation=https://github.com/coreos

[Service]
Type=notify
WorkingDirectory=/var/lib/etcd/
ExecStart=/opt/kubernetes/bin/etcd \
  --data-dir=/var/lib/etcd \
  --name=m1 \
  --cert-file=/etc/kubernetes/pki/etcd.pem \
  --key-file=/etc/kubernetes/pki/etcd-key.pem \
  --trusted-ca-file=/etc/kubernetes/pki/ca.pem \
  --peer-cert-file=/etc/kubernetes/pki/etcd.pem \
  --peer-key-file=/etc/kubernetes/pki/etcd-key.pem \
  --peer-trusted-ca-file=/etc/kubernetes/pki/ca.pem \
  --peer-client-cert-auth \
  --client-cert-auth \
  --listen-peer-urls=https://192.168.243.143:2380 \
  --initial-advertise-peer-urls=https://192.168.243.143:2380 \
  --listen-client-urls=https://192.168.243.143:2379,http://127.0.0.1:2379 \
  --advertise-client-urls=https://192.168.243.143:2379 \
  --initial-cluster-token=etcd-cluster-0 \
  --initial-cluster=m1=https://192.168.243.143:2380,m2=https://192.168.243.144:2380,m3=https://192.168.243.145:2380 \
  --initial-cluster-state=new
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

将该配置文件分发到每个master节点:

[root@m1 ~]# for i in m1 m2 m3; do scp etcd.service $i:/etc/systemd/system/; done

分发完之后,需要在除了m1以外的其他master节点上修改etcd.service文件的内容,主要修改如下几处:

# 修改为所在节点的hostname
--name=m1

# 以下几项则是将ip修改为所在节点的ip,本地ip不用修改
--listen-peer-urls=https://192.168.243.143:2380 
--initial-advertise-peer-urls=https://192.168.243.143:2380 
--listen-client-urls=https://192.168.243.143:2379,http://127.0.0.1:2379 
--advertise-client-urls=https://192.168.243.143:2379 

接着在每个master节点上创建etcd的工作目录:

[root@m1 ~]# for i in m1 m2 m3; do ssh $i "mkdir -p /var/lib/etcd"; done

启动服务

在各个etcd节点上执行如下命令启动etcd服务:

$ systemctl daemon-reload && systemctl enable etcd && systemctl restart etcd
  • Tips:etcd 进程首次启动时会等待其它节点的 etcd 加入集群,命令 systemctl start etcd 会卡住一段时间,为正常现象。

查看服务状态,状态为active (running)代表启动成功:

$ systemctl status etcd

如果没有启动成功,可以查看启动日志排查下问题:

$ journalctl -f -u etcd

部署api-server(master节点)

生成证书和私钥

第一步还是一样的,首先生成api-server的证书和私钥。创建kubernetes-csr.json文件,内容如下:

{
  "CN": "kubernetes",
  "hosts": [
    "127.0.0.1",
    "192.168.243.143",
    "192.168.243.144",
    "192.168.243.145",
    "192.168.243.101",
    "10.255.0.1",
    "kubernetes",
    "kubernetes.default",
    "kubernetes.default.svc",
    "kubernetes.default.svc.cluster",
    "kubernetes.default.svc.cluster.local"
  ],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "seven"
    }
  ]
}

生成证书、私钥:

[root@m1 ~]# cfssl gencert -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -profile=kubernetes kubernetes-csr.json | cfssljson -bare kubernetes
[root@m1 ~]# ls kubernetes*.pem
kubernetes-key.pem  kubernetes.pem
[root@m1 ~]# 

分发到每个master节点:

[root@m1 ~]# for i in m1 m2 m3; do scp kubernetes*.pem $i:/etc/kubernetes/pki/; done

创建service文件

创建kube-apiserver.service文件,内容如下:

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

[Service]
ExecStart=/opt/kubernetes/bin/kube-apiserver \
  --enable-admission-plugins=NamespaceLifecycle,NodeRestriction,LimitRanger,ServiceAccount,DefaultStorageClass,ResourceQuota \
  --anonymous-auth=false \
  --advertise-address=192.168.243.143 \
  --bind-address=0.0.0.0 \
  --insecure-port=0 \
  --authorization-mode=Node,RBAC \
  --runtime-config=api/all=true \
  --enable-bootstrap-token-auth \
  --service-cluster-ip-range=10.255.0.0/16 \
  --service-node-port-range=8400-8900 \
  --tls-cert-file=/etc/kubernetes/pki/kubernetes.pem \
  --tls-private-key-file=/etc/kubernetes/pki/kubernetes-key.pem \
  --client-ca-file=/etc/kubernetes/pki/ca.pem \
  --kubelet-client-certificate=/etc/kubernetes/pki/kubernetes.pem \
  --kubelet-client-key=/etc/kubernetes/pki/kubernetes-key.pem \
  --service-account-key-file=/etc/kubernetes/pki/ca-key.pem \
  --etcd-cafile=/etc/kubernetes/pki/ca.pem \
  --etcd-certfile=/etc/kubernetes/pki/kubernetes.pem \
  --etcd-keyfile=/etc/kubernetes/pki/kubernetes-key.pem \
  --etcd-servers=https://192.168.243.143:2379,https://192.168.243.144:2379,https://192.168.243.145:2379 \
  --enable-swagger-ui=true \
  --allow-privileged=true \
  --apiserver-count=3 \
  --audit-log-maxage=30 \
  --audit-log-maxbackup=3 \
  --audit-log-maxsize=100 \
  --audit-log-path=/var/log/kube-apiserver-audit.log \
  --event-ttl=1h \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=2
Restart=on-failure
RestartSec=5
Type=notify
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

将该配置文件分发到每个master节点:

[root@m1 ~]# for i in m1 m2 m3; do scp kube-apiserver.service $i:/etc/systemd/system/; done

分发完之后,需要在除了m1以外的其他master节点上修改kube-apiserver.service文件的内容。只需要修改以下一项:

# 修改为所在节点的ip即可
--advertise-address=192.168.243.143

然后在所有的master节点上创建api-server的日志目录:

[root@m1 ~]# for i in m1 m2 m3; do ssh $i "mkdir -p /var/log/kubernetes"; done

启动服务

在各个master节点上执行如下命令启动api-server服务:

$ systemctl daemon-reload && systemctl enable kube-apiserver && systemctl restart kube-apiserver

查看服务状态,状态为active (running)代表启动成功:

$ systemctl status kube-apiserver

检查是否有正常监听6443端口:

[root@m1 ~]# netstat -lntp |grep 6443
tcp6       0      0 :::6443                 :::*                    LISTEN      24035/kube-apiserve 
[root@m1 ~]# 

如果没有启动成功,可以查看启动日志排查下问题:

$ journalctl -f -u kube-apiserver

部署keepalived使api-server高可用(master节点)

安装keepalived

在两个主节点上安装keepalived即可(一主一备),我这里选择在m1m2节点上安装:

$ yum install -y keepalived

创建keepalived配置文件

m1m2节点上创建一个目录用于存放keepalived的配置文件:

[root@m1 ~]# for i in m1 m2; do ssh $i "mkdir -p /etc/keepalived"; done

m1(角色为master)上创建配置文件如下:

[root@m1 ~]# mv /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.back
[root@m1 ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
 router_id keepalive-master
}

vrrp_script check_apiserver {
 # 检测脚本路径
 script "/etc/keepalived/check-apiserver.sh"
 # 多少秒检测一次
 interval 3
 # 失败的话权重-2
 weight -2
}

vrrp_instance VI-kube-master {
   state MASTER    # 定义节点角色
   interface ens32  # 网卡名称
   virtual_router_id 68
   priority 100
   dont_track_primary
   advert_int 3
   virtual_ipaddress {
     # 自定义虚拟ip
     192.168.243.101
   }
   track_script {
       check_apiserver
   }
}

m2(角色为backup)上创建配置文件如下:

[root@m1 ~]# mv /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.back
[root@m1 ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
 router_id keepalive-backup
}

vrrp_script check_apiserver {
 script "/etc/keepalived/check-apiserver.sh"
 interval 3
 weight -2
}

vrrp_instance VI-kube-master {
   state BACKUP
   interface ens32
   virtual_router_id 68
   priority 99
   dont_track_primary
   advert_int 3
   virtual_ipaddress {
     192.168.243.101
   }
   track_script {
       check_apiserver
   }
}

分别在m1m2节点上创建keepalived的检测脚本:

$ vim /etc/keepalived/check-apiserver.sh  # 创建检测脚本,内容如下
#!/bin/sh

errorExit() {
   echo "*** $*" 1>&2
   exit 1
}

# 检查本机api-server是否正常
curl --silent --max-time 2 --insecure https://localhost:6443/ -o /dev/null || errorExit "Error GET https://localhost:6443/"
# 如果虚拟ip绑定在本机上,则检查能否通过虚拟ip正常访问到api-server
if ip addr | grep -q 192.168.243.101; then
   curl --silent --max-time 2 --insecure https://192.168.243.101:6443/ -o /dev/null || errorExit "Error GET https://192.168.243.101:6443/"
fi

启动keepalived

分别在master和backup上启动keepalived服务:

$ systemctl enable keepalived && service keepalived start

查看服务状态,状态为active (running)代表启动成功:

$ systemctl status keepalived

查看有无正常绑定虚拟ip:

$ ip a |grep 192.168.243.101

访问测试,能返回数据代表服务是正在运行的:

[root@m1 ~]# curl --insecure https://192.168.243.101:6443/
{
  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {
    
  },
  "status": "Failure",
  "message": "Unauthorized",
  "reason": "Unauthorized",
  "code": 401
}
[root@m1 ~]#

如果没有启动成功,可以查看日志排查下问题:

$ journalctl -f -u keepalived

部署kubectl(任意节点)

kubectl 是 kubernetes 集群的命令行管理工具,它默认从 ~/.kube/config 文件读取 kube-apiserver 地址、证书、用户名等信息。

创建 admin 证书和私钥

kubectl 与 apiserver https 安全端口通信,apiserver 对提供的证书进行认证和授权。kubectl 作为集群的管理工具,需要被授予最高权限,所以这里创建具有最高权限的 admin 证书。首先创建admin-csr.json文件,内容如下:

{
  "CN": "admin",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "system:masters",
      "OU": "seven"
    }
  ]
}

使用cfssl工具创建证书和私钥:

[root@m1 ~]# cfssl gencert -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -profile=kubernetes admin-csr.json | cfssljson -bare admin
[root@m1 ~]# ls admin*.pem
admin-key.pem  admin.pem
[root@m1 ~]#   

创建kubeconfig配置文件

kubeconfigkubectl 的配置文件,包含访问 apiserver 的所有信息,如 apiserver 地址、CA 证书和自身使用的证书。

1、设置集群参数:

[root@m1 ~]# kubectl config set-cluster kubernetes \
  --certificate-authority=ca.pem \
  --embed-certs=true \
  --server=https://192.168.243.101:6443 \
  --kubeconfig=kube.config

2、设置客户端认证参数:

[root@m1 ~]# kubectl config set-credentials admin \
  --client-certificate=admin.pem \
  --client-key=admin-key.pem \
  --embed-certs=true \
  --kubeconfig=kube.config

3、设置上下文参数:

[root@m1 ~]# kubectl config set-context kubernetes \
  --cluster=kubernetes \
  --user=admin \
  --kubeconfig=kube.config

4、设置默认上下文:

[root@m1 ~]# kubectl config use-context kubernetes --kubeconfig=kube.config

5、拷贝文件配置文件并重命名为~/.kube/config

[root@m1 ~]# cp kube.config ~/.kube/config

授予 kubernetes 证书访问 kubelet API 的权限

在执行 kubectl execrunlogs 等命令时,apiserver 会转发到 kubelet。这里定义 RBAC 规则,授权 apiserver 调用 kubelet API。

[root@m1 ~]# kubectl create clusterrolebinding kube-apiserver:kubelet-apis --clusterrole=system:kubelet-api-admin --user kubernetes
clusterrolebinding.rbac.authorization.k8s.io/kube-apiserver:kubelet-apis created
[root@m1 ~]# 

测试kubectl

1、查看集群信息:

[root@m1 ~]# kubectl cluster-info
Kubernetes master is running at https://192.168.243.101:6443

To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
[root@m1 ~]# 

2、查看集群中所有命名空间下的资源信息:

[root@m1 ~]# kubectl get all --all-namespaces
NAMESPACE   NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
default     service/kubernetes   ClusterIP   10.255.0.1   <none>        443/TCP   43m
[root@m1 ~]# 

4、查看集群中的组件状态:

[root@m1 ~]# kubectl get componentstatuses
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS      MESSAGE                                                                                       ERROR
scheduler            Unhealthy   Get "http://127.0.0.1:10251/healthz": dial tcp 127.0.0.1:10251: connect: connection refused   
controller-manager   Unhealthy   Get "http://127.0.0.1:10252/healthz": dial tcp 127.0.0.1:10252: connect: connection refused   
etcd-0               Healthy     {"health":"true"}                                                                             
etcd-1               Healthy     {"health":"true"}                                                                             
etcd-2               Healthy     {"health":"true"}                                                                             
[root@m1 ~]# 

配置kubectl命令补全

kubectl是用于与k8s集群交互的一个命令行工具,操作k8s基本离不开这个工具,所以该工具所支持的命令比较多。好在kubectl支持设置命令补全,使用kubectl completion -h可以查看各个平台下的设置示例。这里以Linux平台为例,演示一下如何设置这个命令补全,完成以下操作后就可以使用tap键补全命令了:

[root@m1 ~]# yum install bash-completion -y
[root@m1 ~]# source /usr/share/bash-completion/bash_completion
[root@m1 ~]# source <(kubectl completion bash)
[root@m1 ~]# kubectl completion bash > ~/.kube/completion.bash.inc
[root@m1 ~]# printf "  
# Kubectl shell completion  
source '$HOME/.kube/completion.bash.inc'  
" >> $HOME/.bash_profile
[root@m1 ~]# source $HOME/.bash_profile

部署controller-manager(master节点)

controller-manager启动后将通过竞争选举机制产生一个 leader 节点,其它节点为阻塞状态。当 leader 节点不可用后,剩余节点将再次进行选举产生新的 leader 节点,从而保证服务的可用性。

创建证书和私钥

创建controller-manager-csr.json文件,内容如下:

{
    "CN": "system:kube-controller-manager",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "hosts": [
      "127.0.0.1",
      "192.168.243.143",
      "192.168.243.144",
      "192.168.243.145"
    ],
    "names": [
      {
        "C": "CN",
        "ST": "BeiJing",
        "L": "BeiJing",
        "O": "system:kube-controller-manager",
        "OU": "seven"
      }
    ]
}

生成证书、私钥:

[root@m1 ~]# cfssl gencert -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -profile=kubernetes controller-manager-csr.json | cfssljson -bare controller-manager
[root@m1 ~]# ls controller-manager*.pem
controller-manager-key.pem  controller-manager.pem
[root@m1 ~]# 

分发到每个master节点:

[root@m1 ~]# for i in m1 m2 m3; do scp controller-manager*.pem $i:/etc/kubernetes/pki/; done

创建controller-manager的kubeconfig

创建kubeconfig

# 设置集群参数
[root@m1 ~]# kubectl config set-cluster kubernetes \
  --certificate-authority=ca.pem \
  --embed-certs=true \
  --server=https://192.168.243.101:6443 \
  --kubeconfig=controller-manager.kubeconfig

# 设置客户端认证参数
[root@m1 ~]# kubectl config set-credentials system:kube-controller-manager \
  --client-certificate=controller-manager.pem \
  --client-key=controller-manager-key.pem \
  --embed-certs=true \
  --kubeconfig=controller-manager.kubeconfig

# 设置上下文参数
[root@m1 ~]# kubectl config set-context system:kube-controller-manager \
  --cluster=kubernetes \
  --user=system:kube-controller-manager \
  --kubeconfig=controller-manager.kubeconfig

设置默认上下文:

[root@m1 ~]# kubectl config use-context system:kube-controller-manager --kubeconfig=controller-manager.kubeconfig

分发controller-manager.kubeconfig文件到每个master节点上:

[root@m1 ~]# for i in m1 m2 m3; do scp controller-manager.kubeconfig $i:/etc/kubernetes/; done

创建service文件

创建kube-controller-manager.service文件,内容如下:

[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/GoogleCloudPlatform/kubernetes

[Service]
ExecStart=/opt/kubernetes/bin/kube-controller-manager \
  --port=0 \
  --secure-port=10252 \
  --bind-address=127.0.0.1 \
  --kubeconfig=/etc/kubernetes/controller-manager.kubeconfig \
  --service-cluster-ip-range=10.255.0.0/16 \
  --cluster-name=kubernetes \
  --cluster-signing-cert-file=/etc/kubernetes/pki/ca.pem \
  --cluster-signing-key-file=/etc/kubernetes/pki/ca-key.pem \
  --allocate-node-cidrs=true \
  --cluster-cidr=172.23.0.0/16 \
  --experimental-cluster-signing-duration=87600h \
  --root-ca-file=/etc/kubernetes/pki/ca.pem \
  --service-account-private-key-file=/etc/kubernetes/pki/ca-key.pem \
  --leader-elect=true \
  --feature-gates=RotateKubeletServerCertificate=true \
  --controllers=*,bootstrapsigner,tokencleaner \
  --horizontal-pod-autoscaler-use-rest-clients=true \
  --horizontal-pod-autoscaler-sync-period=10s \
  --tls-cert-file=/etc/kubernetes/pki/controller-manager.pem \
  --tls-private-key-file=/etc/kubernetes/pki/controller-manager-key.pem \
  --use-service-account-credentials=true \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=2
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target

kube-controller-manager.service配置文件分发到每个master节点上:

[root@m1 ~]# for i in m1 m2 m3; do scp kube-controller-manager.service $i:/etc/systemd/system/; done

启动服务

在各个master节点上启动kube-controller-manager服务,具体命令如下:

$ systemctl daemon-reload && systemctl enable kube-controller-manager && systemctl restart kube-controller-manager

查看服务状态,状态为active (running)代表启动成功:

$ systemctl status kube-controller-manager

查看leader信息:

[root@m1 ~]# kubectl get endpoints kube-controller-manager --namespace=kube-system -o yaml
apiVersion: v1
kind: Endpoints
metadata:
  annotations:
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"m1_ae36dc74-68d0-444d-8931-06b37513990a","leaseDurationSeconds":15,"acquireTime":"2020-09-04T15:47:14Z","renewTime":"2020-09-04T15:47:39Z","leaderTransitions":0}'
  creationTimestamp: "2020-09-04T15:47:15Z"
  managedFields:
  - apiVersion: v1
    fieldsType: FieldsV1
    fieldsV1:
      f:metadata:
        f:annotations:
          .: {}
          f:control-plane.alpha.kubernetes.io/leader: {}
    manager: kube-controller-manager
    operation: Update
    time: "2020-09-04T15:47:39Z"
  name: kube-controller-manager
  namespace: kube-system
  resourceVersion: "1908"
  selfLink: /api/v1/namespaces/kube-system/endpoints/kube-controller-manager
  uid: 149b117e-f7c4-4ad8-bc83-09345886678a
[root@m1 ~]# 

如果没有启动成功,可以查看日志排查下问题:

$ journalctl -f -u kube-controller-manager

部署scheduler(master节点)

scheduler启动后将通过竞争选举机制产生一个 leader 节点,其它节点为阻塞状态。当 leader 节点不可用后,剩余节点将再次进行选举产生新的 leader 节点,从而保证服务的可用性。

创建证书和私钥

创建scheduler-csr.json文件,内容如下:

{
    "CN": "system:kube-scheduler",
    "hosts": [
      "127.0.0.1",
      "192.168.243.143",
      "192.168.243.144",
      "192.168.243.145"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
      {
        "C": "CN",
        "ST": "BeiJing",
        "L": "BeiJing",
        "O": "system:kube-scheduler",
        "OU": "seven"
      }
    ]
}

生成证书和私钥:

[root@m1 ~]# cfssl gencert -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -profile=kubernetes scheduler-csr.json | cfssljson -bare kube-scheduler
[root@m1 ~]# ls kube-scheduler*.pem
kube-scheduler-key.pem  kube-scheduler.pem
[root@m1 ~]# 

分发到每个master节点:

[root@m1 ~]# for i in m1 m2 m3; do scp kube-scheduler*.pem $i:/etc/kubernetes/pki/; done

创建scheduler的kubeconfig

创建kubeconfig

# 设置集群参数
[root@m1 ~]# kubectl config set-cluster kubernetes \
  --certificate-authority=ca.pem \
  --embed-certs=true \
  --server=https://192.168.243.101:6443 \
  --kubeconfig=kube-scheduler.kubeconfig

# 设置客户端认证参数
[root@m1 ~]# kubectl config set-credentials system:kube-scheduler \
  --client-certificate=kube-scheduler.pem \
  --client-key=kube-scheduler-key.pem \
  --embed-certs=true \
  --kubeconfig=kube-scheduler.kubeconfig

# 设置上下文参数
[root@m1 ~]# kubectl config set-context system:kube-scheduler \
  --cluster=kubernetes \
  --user=system:kube-scheduler \
  --kubeconfig=kube-scheduler.kubeconfig

设置默认上下文:

[root@m1 ~]# kubectl config use-context system:kube-scheduler --kubeconfig=kube-scheduler.kubeconfig

分发kube-scheduler.kubeconfig文件到每个master节点上:

[root@m1 ~]# for i in m1 m2 m3; do scp kube-scheduler.kubeconfig $i:/etc/kubernetes/; done

创建service文件

创建kube-scheduler.service文件,内容如下:

[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/GoogleCloudPlatform/kubernetes

[Service]
ExecStart=/opt/kubernetes/bin/kube-scheduler \
  --address=127.0.0.1 \
  --kubeconfig=/etc/kubernetes/kube-scheduler.kubeconfig \
  --leader-elect=true \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=2
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target

kube-scheduler.service配置文件分发到每个master节点上:

[root@m1 ~]# for i in m1 m2 m3; do scp kube-scheduler.service $i:/etc/systemd/system/; done

启动服务

在每个master节点上启动kube-scheduler服务:

$ systemctl daemon-reload && systemctl enable kube-scheduler && systemctl restart kube-scheduler

查看服务状态,状态为active (running)代表启动成功:

$ service kube-scheduler status

查看leader信息:

[root@m1 ~]# kubectl get endpoints kube-scheduler --namespace=kube-system -o yaml
apiVersion: v1
kind: Endpoints
metadata:
  annotations:
    control-plane.alpha.kubernetes.io/leader: '{"holderIdentity":"m1_f6c4da9f-85b4-47e2-919d-05b24b4aacac","leaseDurationSeconds":15,"acquireTime":"2020-09-04T16:03:57Z","renewTime":"2020-09-04T16:04:19Z","leaderTransitions":0}'
  creationTimestamp: "2020-09-04T16:03:57Z"
  managedFields:
  - apiVersion: v1
    fieldsType: FieldsV1
    fieldsV1:
      f:metadata:
        f:annotations:
          .: {}
          f:control-plane.alpha.kubernetes.io/leader: {}
    manager: kube-scheduler
    operation: Update
    time: "2020-09-04T16:04:19Z"
  name: kube-scheduler
  namespace: kube-system
  resourceVersion: "3230"
  selfLink: /api/v1/namespaces/kube-system/endpoints/kube-scheduler
  uid: c2f2210d-b00f-4157-b597-d3e3b4bec38b
[root@m1 ~]# 

如果没有启动成功,可以查看日志排查下问题:

$ journalctl -f -u kube-scheduler

部署kubelet(worker节点)

预先下载需要的docker镜像

首先我们需要预先下载镜像到所有的节点上,由于有些镜像不翻墙无法下载,所以这里提供了一个简单的脚本拉取阿里云仓库的镜像并修改了tag

[root@m1 ~]# vim download-images.sh
#!/bin/bash

docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.2
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.2 k8s.gcr.io/pause-amd64:3.2
docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/pause-amd64:3.2

docker pull registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.7.0
docker tag registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.7.0 k8s.gcr.io/coredns:1.7.0
docker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.7.0

将脚本分发到其他节点上:

[root@m1 ~]# for i in m2 m3 n1 n2; do scp download-images.sh $i:~; done

然后让每个节点执行该脚本:

[root@m1 ~]# for i in m1 m2 m3 n1 n2; do ssh $i "sh ~/download-images.sh"; done

拉取完成后,此时各个节点应有如下镜像:

$ docker images
REPOSITORY               TAG                 IMAGE ID            CREATED             SIZE
k8s.gcr.io/coredns       1.7.0               bfe3a36ebd25        2 months ago        45.2MB
k8s.gcr.io/pause-amd64   3.2                 80d28bedfe5d        6 months ago        683kB

创建bootstrap配置文件

创建 token 并设置环境变量:

[root@m1 ~]# export BOOTSTRAP_TOKEN=$(kubeadm token create \
      --description kubelet-bootstrap-token \
      --groups system:bootstrappers:worker \
      --kubeconfig kube.config)

创建kubelet-bootstrap.kubeconfig

# 设置集群参数
[root@m1 ~]# kubectl config set-cluster kubernetes \
      --certificate-authority=ca.pem \
      --embed-certs=true \
      --server=https://192.168.243.101:6443 \
      --kubeconfig=kubelet-bootstrap.kubeconfig

# 设置客户端认证参数
[root@m1 ~]# kubectl config set-credentials kubelet-bootstrap \
      --token=${BOOTSTRAP_TOKEN} \
      --kubeconfig=kubelet-bootstrap.kubeconfig

# 设置上下文参数
[root@m1 ~]# kubectl config set-context default \
      --cluster=kubernetes \
      --user=kubelet-bootstrap \
      --kubeconfig=kubelet-bootstrap.kubeconfig

设置默认上下文:

[root@m1 ~]# kubectl config use-context default --kubeconfig=kubelet-bootstrap.kubeconfig

在worker节点上创建k8s配置文件存储目录并把生成的配置文件copy到每个worker节点上:

[root@m1 ~]# for i in n1 n2; do ssh $i "mkdir /etc/kubernetes/"; done
[root@m1 ~]# for i in n1 n2; do scp kubelet-bootstrap.kubeconfig $i:/etc/kubernetes/kubelet-bootstrap.kubeconfig; done

worker节点上创建密钥存放目录:

[root@m1 ~]# for i in n1 n2; do ssh $i "mkdir -p /etc/kubernetes/pki"; done

把CA证书分发到每个worker节点上:

[root@m1 ~]# for i in n1 n2; do scp ca.pem $i:/etc/kubernetes/pki/; done

kubelet配置文件

创建kubelet.config.json配置文件,内容如下:

{
  "kind": "KubeletConfiguration",
  "apiVersion": "kubelet.config.k8s.io/v1beta1",
  "authentication": {
    "x509": {
      "clientCAFile": "/etc/kubernetes/pki/ca.pem"
    },
    "webhook": {
      "enabled": true,
      "cacheTTL": "2m0s"
    },
    "anonymous": {
      "enabled": false
    }
  },
  "authorization": {
    "mode": "Webhook",
    "webhook": {
      "cacheAuthorizedTTL": "5m0s",
      "cacheUnauthorizedTTL": "30s"
    }
  },
  "address": "192.168.243.146",
  "port": 10250,
  "readOnlyPort": 10255,
  "cgroupDriver": "cgroupfs",
  "hairpinMode": "promiscuous-bridge",
  "serializeImagePulls": false,
  "featureGates": {
    "RotateKubeletClientCertificate": true,
    "RotateKubeletServerCertificate": true
  },
  "clusterDomain": "cluster.local.",
  "clusterDNS": ["10.255.0.2"]
}

kubelet配置文件分发到每个worker节点上:

[root@m1 ~]# for i in n1 n2; do scp kubelet.config.json $i:/etc/kubernetes/; done

注意:分发完成后需要修改配置文件中的address字段,改为所在节点的IP

kubelet服务文件

创建kubelet.service文件,内容如下:

[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 \
  --bootstrap-kubeconfig=/etc/kubernetes/kubelet-bootstrap.kubeconfig \
  --cert-dir=/etc/kubernetes/pki \
  --kubeconfig=/etc/kubernetes/kubelet.kubeconfig \
  --config=/etc/kubernetes/kubelet.config.json \
  --network-plugin=cni \
  --pod-infra-container-image=k8s.gcr.io/pause-amd64:3.2 \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=2
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target

kubelet的服务文件分发到每个worker节点上

[root@m1 ~]# for i in n1 n2; do scp kubelet.service $i:/etc/systemd/system/; done

启动服务

kublet 启动时会查找 --kubeletconfig 参数配置的文件是否存在,如果不存在则使用 --bootstrap-kubeconfig 向 kube-apiserver 发送证书签名请求 (CSR)。

kube-apiserver 收到 CSR 请求后,对其中的 Token 进行认证(事先使用 kubeadm 创建的 token),认证通过后将请求的 user 设置为 system:bootstrap:group 设置为 system:bootstrappers,这就是Bootstrap Token Auth。

bootstrap赋权,即创建一个角色绑定:

[root@m1 ~]# kubectl create clusterrolebinding kubelet-bootstrap --clusterrole=system:node-bootstrapper --group=system:bootstrappers

然后就可以启动kubelet服务了,在每个worker节点上执行如下命令:

$ mkdir -p /var/lib/kubelet
$ systemctl daemon-reload && systemctl enable kubelet && systemctl restart kubelet

查看服务状态,状态为active (running)代表启动成功:

$ systemctl status kubelet

如果没有启动成功,可以查看日志排查下问题:

$ journalctl -f -u kubelet

确认kubelet服务启动成功后,接着到master上Approve一下bootstrap请求。执行如下命令可以看到两个worker节点分别发送了两个 CSR 请求:

[root@m1 ~]# kubectl get csr
NAME                                                   AGE   SIGNERNAME                                    REQUESTOR                 CONDITION
node-csr-0U6dO2MrD_KhUCdofq1rab6yrLvuVMJkAXicLldzENE   27s   kubernetes.io/kube-apiserver-client-kubelet   system:bootstrap:seh1w7   Pending
node-csr-QMAVx75MnxCpDT5QtI6liNZNfua39vOwYeUyiqTIuPg   74s   kubernetes.io/kube-apiserver-client-kubelet   system:bootstrap:seh1w7   Pending
[root@m1 ~]# 

然后Approve这两个请求即可:

[root@m1 ~]# kubectl certificate approve node-csr-0U6dO2MrD_KhUCdofq1rab6yrLvuVMJkAXicLldzENE
certificatesigningrequest.certificates.k8s.io/node-csr-0U6dO2MrD_KhUCdofq1rab6yrLvuVMJkAXicLldzENE approved
[root@m1 ~]# kubectl certificate approve node-csr-QMAVx75MnxCpDT5QtI6liNZNfua39vOwYeUyiqTIuPg
certificatesigningrequest.certificates.k8s.io/node-csr-QMAVx75MnxCpDT5QtI6liNZNfua39vOwYeUyiqTIuPg approved
[root@m1 ~]# 

部署kube-proxy(worker节点)

创建证书和私钥

创建 kube-proxy-csr.json 文件,内容如下:

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

生成证书和私钥:

[root@m1 ~]# cfssl gencert -ca=ca.pem \
  -ca-key=ca-key.pem \
  -config=ca-config.json \
  -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy
[root@m1 ~]# ls kube-proxy*.pem
kube-proxy-key.pem  kube-proxy.pem
[root@m1 ~]# 

创建和分发 kubeconfig 文件

执行如下命令创建kube-proxy.kubeconfig文件:

# 设置集群参数
[root@m1 ~]# kubectl config set-cluster kubernetes \
  --certificate-authority=ca.pem \
  --embed-certs=true \
  --server=https://192.168.243.101:6443 \
  --kubeconfig=kube-proxy.kubeconfig

# 设置客户端认证参数
[root@m1 ~]# kubectl config set-credentials kube-proxy \
  --client-certificate=kube-proxy.pem \
  --client-key=kube-proxy-key.pem \
  --embed-certs=true \
  --kubeconfig=kube-proxy.kubeconfig

# 设置上下文参数
[root@m1 ~]# kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-proxy \
  --kubeconfig=kube-proxy.kubeconfig

切换默认上下文:

[root@m1 ~]# kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig

分发kube-proxy.kubeconfig文件到各个worker节点上:

[root@m1 ~]# for i in n1 n2; do scp kube-proxy.kubeconfig $i:/etc/kubernetes/; done

创建和分发kube-proxy配置文件

创建kube-proxy.config.yaml文件,内容如下:

apiVersion: kubeproxy.config.k8s.io/v1alpha1
# 修改为所在节点的ip
bindAddress: {worker_ip}
clientConnection:
  kubeconfig: /etc/kubernetes/kube-proxy.kubeconfig
clusterCIDR: 172.23.0.0/16
# 修改为所在节点的ip
healthzBindAddress: {worker_ip}:10256
kind: KubeProxyConfiguration
# 修改为所在节点的ip
metricsBindAddress: {worker_ip}:10249
mode: "iptables"

kube-proxy.config.yaml文件分发到每个worker节点上:

[root@m1 ~]# for i in n1 n2; do scp kube-proxy.config.yaml $i:/etc/kubernetes/; done

创建和分发kube-proxy服务文件

创建kube-proxy.service文件,内容如下:

[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 \
  --config=/etc/kubernetes/kube-proxy.config.yaml \
  --alsologtostderr=true \
  --logtostderr=false \
  --log-dir=/var/log/kubernetes \
  --v=2
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

kube-proxy.service文件分发到所有worker节点上:

[root@m1 ~]# for i in n1 n2; do scp kube-proxy.service $i:/etc/systemd/system/; done

启动服务

创建kube-proxy服务所依赖的目录:

[root@m1 ~]# for i in n1 n2; do ssh $i "mkdir -p /var/lib/kube-proxy && mkdir -p /var/log/kubernetes"; done

然后就可以启动kube-proxy服务了,在每个worker节点上执行如下命令:

$ systemctl daemon-reload && systemctl enable kube-proxy && systemctl restart kube-proxy

查看服务状态,状态为active (running)代表启动成功:

$ systemctl status kube-proxy

如果没有启动成功,可以查看日志排查下问题:

$ journalctl -f -u kube-proxy

部署CNI插件 - calico

我们使用calico官方的安装方式来部署。创建目录(在配置了kubectl的节点上执行):

[root@m1 ~]# mkdir -p /etc/kubernetes/addons

在该目录下创建calico-rbac-kdd.yaml文件,内容如下:

kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: calico-node
rules:
  - apiGroups: [""]
    resources:
      - namespaces
    verbs:
      - get
      - list
      - watch
  - apiGroups: [""]
    resources:
      - pods/status
    verbs:
      - update
  - apiGroups: [""]
    resources:
      - pods
    verbs:
      - get
      - list
      - watch
      - patch
  - apiGroups: [""]
    resources:
      - services
    verbs:
      - get
  - apiGroups: [""]
    resources:
      - endpoints
    verbs:
      - get
  - apiGroups: [""]
    resources:
      - nodes
    verbs:
      - get
      - list
      - update
      - watch
  - apiGroups: ["extensions"]
    resources:
      - networkpolicies
    verbs:
      - get
      - list
      - watch
  - apiGroups: ["networking.k8s.io"]
    resources:
      - networkpolicies
    verbs:
      - watch
      - list
  - apiGroups: ["crd.projectcalico.org"]
    resources:
      - globalfelixconfigs
      - felixconfigurations
      - bgppeers
      - globalbgpconfigs
      - bgpconfigurations
      - ippools
      - globalnetworkpolicies
      - globalnetworksets
      - networkpolicies
      - clusterinformations
      - hostendpoints
    verbs:
      - create
      - get
      - list
      - update
      - watch

---

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: calico-node
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: calico-node
subjects:
- kind: ServiceAccount
  name: calico-node
  namespace: kube-system

然后分别执行如下命令完成calico的安装:

[root@m1 ~]# kubectl apply -f /etc/kubernetes/addons/calico-rbac-kdd.yaml
[root@m1 ~]# kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml

等待几分钟后查看Pod状态,均为Running才代表部署成功:

[root@m1 ~]# kubectl get pod --all-namespaces 
NAMESPACE     NAME                                       READY   STATUS    RESTARTS   AGE
kube-system   calico-kube-controllers-5bc4fc6f5f-z8lhf   1/1     Running   0          105s
kube-system   calico-node-qflvj                          1/1     Running   0          105s
kube-system   calico-node-x9m2n                          1/1     Running   0          105s
[root@m1 ~]# 

部署DNS插件 - coredns

/etc/kubernetes/addons/目录下创建coredns.yaml配置文件:

apiVersion: v1
kind: ServiceAccount
metadata:
  name: coredns
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  name: system:coredns
rules:
- apiGroups:
  - ""
  resources:
  - endpoints
  - services
  - pods
  - namespaces
  verbs:
  - list
  - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  name: system:coredns
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:coredns
subjects:
- kind: ServiceAccount
  name: coredns
  namespace: kube-system
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: coredns
  namespace: kube-system
data:
  Corefile: |
    .:53 {
        errors
        health {
          lameduck 5s
        }
        ready
        kubernetes cluster.local in-addr.arpa ip6.arpa {
          fallthrough in-addr.arpa ip6.arpa
        }
        prometheus :9153
        forward . /etc/resolv.conf {
          max_concurrent 1000
        }
        cache 30
        loop
        reload
        loadbalance
    }
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: coredns
  namespace: kube-system
  labels:
    k8s-app: kube-dns
    kubernetes.io/name: "CoreDNS"
spec:
  # replicas: not specified here:
  # 1. Default is 1.
  # 2. Will be tuned in real time if DNS horizontal auto-scaling is turned on.
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 1
  selector:
    matchLabels:
      k8s-app: kube-dns
  template:
    metadata:
      labels:
        k8s-app: kube-dns
    spec:
      priorityClassName: system-cluster-critical
      serviceAccountName: coredns
      tolerations:
        - key: "CriticalAddonsOnly"
          operator: "Exists"
      nodeSelector:
        kubernetes.io/os: linux
      affinity:
         podAntiAffinity:
           preferredDuringSchedulingIgnoredDuringExecution:
           - weight: 100
             podAffinityTerm:
               labelSelector:
                 matchExpressions:
                   - key: k8s-app
                     operator: In
                     values: ["kube-dns"]
               topologyKey: kubernetes.io/hostname
      containers:
      - name: coredns
        image: coredns/coredns:1.7.0
        imagePullPolicy: IfNotPresent
        resources:
          limits:
            memory: 170Mi
          requests:
            cpu: 100m
            memory: 70Mi
        args: [ "-conf", "/etc/coredns/Corefile" ]
        volumeMounts:
        - name: config-volume
          mountPath: /etc/coredns
          readOnly: true
        ports:
        - containerPort: 53
          name: dns
          protocol: UDP
        - containerPort: 53
          name: dns-tcp
          protocol: TCP
        - containerPort: 9153
          name: metrics
          protocol: TCP
        securityContext:
          allowPrivilegeEscalation: false
          capabilities:
            add:
            - NET_BIND_SERVICE
            drop:
            - all
          readOnlyRootFilesystem: true
        livenessProbe:
          httpGet:
            path: /health
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 60
          timeoutSeconds: 5
          successThreshold: 1
          failureThreshold: 5
        readinessProbe:
          httpGet:
            path: /ready
            port: 8181
            scheme: HTTP
      dnsPolicy: Default
      volumes:
        - name: config-volume
          configMap:
            name: coredns
            items:
            - key: Corefile
              path: Corefile
---
apiVersion: v1
kind: Service
metadata:
  name: kube-dns
  namespace: kube-system
  annotations:
    prometheus.io/port: "9153"
    prometheus.io/scrape: "true"
  labels:
    k8s-app: kube-dns
    kubernetes.io/cluster-service: "true"
    kubernetes.io/name: "CoreDNS"
spec:
  selector:
    k8s-app: kube-dns
  clusterIP: 10.255.0.2
  ports:
  - name: dns
    port: 53
    protocol: UDP
  - name: dns-tcp
    port: 53
    protocol: TCP
  - name: metrics
    port: 9153
    protocol: TCP
  • Tips:该文件是使用官方的deploy.sh脚本生成的,执行该脚本时需使用-i参数指定dns的clusterIP,通常为kubernetes服务ip网段的第二个,ip相关的定义在本文开头有说明

然后执行如下命令部署coredns

[root@m1 ~]# kubectl create -f /etc/kubernetes/addons/coredns.yaml
serviceaccount/coredns created
clusterrole.rbac.authorization.k8s.io/system:coredns created
clusterrolebinding.rbac.authorization.k8s.io/system:coredns created
configmap/coredns created
deployment.apps/coredns created
service/kube-dns created
[root@m1 ~]# 

查看Pod状态:

[root@m1 ~]# kubectl get pod --all-namespaces | grep coredns
kube-system   coredns-7bf4bd64bd-ww4q2       1/1     Running   0          3m40s
[root@m1 ~]# 

查看集群中的节点状态:

[root@m1 ~]# kubectl get node
NAME   STATUS   ROLES    AGE     VERSION
n1     Ready    <none>   3h30m   v1.19.0
n2     Ready    <none>   3h30m   v1.19.0
[root@m1 ~]# 

集群可用性测试

创建nginx ds

m1节点上创建nginx-ds.yml配置文件,内容如下:

apiVersion: v1
kind: Service
metadata:
  name: nginx-ds
  labels:
    app: nginx-ds
spec:
  type: NodePort
  selector:
    app: nginx-ds
  ports:
  - name: http
    port: 80
    targetPort: 80
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: nginx-ds
  labels:
    addonmanager.kubernetes.io/mode: Reconcile
spec:
  selector:
    matchLabels:
      app: nginx-ds
  template:
    metadata:
      labels:
        app: nginx-ds
    spec:
      containers:
      - name: my-nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80

然后执行如下命令创建nginx ds:

[root@m1 ~]# kubectl create -f nginx-ds.yml
service/nginx-ds created
daemonset.apps/nginx-ds created
[root@m1 ~]# 

检查各种ip连通性

稍等一会后,检查Pod状态是否正常:

[root@m1 ~]# kubectl get pods -o wide
NAME             READY   STATUS    RESTARTS   AGE   IP              NODE   NOMINATED NODE   READINESS GATES
nginx-ds-4f48f   1/1     Running   0          63s   172.16.40.130   n1     <none>           <none>
nginx-ds-zsm7d   1/1     Running   0          63s   172.16.217.10   n2     <none>           <none>
[root@m1 ~]# 

在每个worker节点上去尝试ping Pod IP(master节点没有安装calico所以不能访问Pod IP):

[root@n1 ~]# ping 172.16.40.130
PING 172.16.40.130 (172.16.40.130) 56(84) bytes of data.
64 bytes from 172.16.40.130: icmp_seq=1 ttl=64 time=0.073 ms
64 bytes from 172.16.40.130: icmp_seq=2 ttl=64 time=0.055 ms
64 bytes from 172.16.40.130: icmp_seq=3 ttl=64 time=0.052 ms
64 bytes from 172.16.40.130: icmp_seq=4 ttl=64 time=0.054 ms
^C
--- 172.16.40.130 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 2999ms
rtt min/avg/max/mdev = 0.052/0.058/0.073/0.011 ms
[root@n1 ~]# 

确认Pod IP能够ping通后,检查Service的状态:

[root@m1 ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)       AGE
kubernetes   ClusterIP   10.255.0.1     <none>        443/TCP       17h
nginx-ds     NodePort    10.255.4.100   <none>        80:8568/TCP   11m
[root@m1 ~]# 

在每个worker节点上尝试访问nginx-ds服务(master节点没有proxy所以不能访问Service IP):

[root@n1 ~]# curl 10.255.4.100:80
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
        width: 35em;
        margin: 0 auto;
        font-family: Tahoma, Verdana, Arial, sans-serif;
    }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>
[root@n1 ~]# 

在每个节点上检查NodePort的可用性,NodePort会将服务的端口与宿主机的端口做映射,正常情况下所有节点都可以通过worker节点的 IP + NodePort 访问到nginx-ds服务:

$ curl 192.168.243.146:8568
$ curl 192.168.243.147:8568

检查dns可用性

需要创建一个Nginx Pod,首先定义一个pod-nginx.yaml配置文件,内容如下:

apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  containers:
  - name: nginx
    image: nginx:1.7.9
    ports:
    - containerPort: 80

然后基于该配置文件去创建Pod:

[root@m1 ~]# kubectl create -f pod-nginx.yaml
pod/nginx created
[root@m1 ~]# 

使用如下命令进入到Pod里:

[root@m1 ~]# kubectl exec nginx -i -t -- /bin/bash

查看dns配置,nameserver的值需为 coredns 的clusterIP

root@nginx:/# cat /etc/resolv.conf
nameserver 10.255.0.2
search default.svc.cluster.local. svc.cluster.local. cluster.local. localdomain
options ndots:5
root@nginx:/# 

接着测试是否可以正确解析Service的名称。如下能根据nginx-ds这个名称解析出对应的IP:10.255.4.100,代表dns也是正常的:

root@nginx:/# ping nginx-ds
PING nginx-ds.default.svc.cluster.local (10.255.4.100): 48 data bytes

kubernetes服务也能正常解析:

root@nginx:/# ping kubernetes
PING kubernetes.default.svc.cluster.local (10.255.0.1): 48 data bytes

高可用测试

m1节点上的kubectl配置文件拷贝到其他两台master节点上:

[root@m1 ~]# for i in m2 m3; do ssh $i "mkdir ~/.kube/"; done
[root@m1 ~]# for i in m2 m3; do scp ~/.kube/config $i:~/.kube/; done

m1节点上执行如下命令将其关机:

[root@m1 ~]# init 0

然后查看虚拟IP是否成功漂移到了m2节点上:

[root@m2 ~]# ip a |grep 192.168.243.101
    inet 192.168.243.101/32 scope global ens32
[root@m2 ~]# 

接着测试能否在m2m3节点上使用kubectl与集群进行交互,能正常交互则代表集群已经具备了高可用:

[root@m2 ~]# kubectl get nodes
NAME   STATUS   ROLES    AGE    VERSION
n1     Ready    <none>   4h2m   v1.19.0
n2     Ready    <none>   4h2m   v1.19.0
[root@m2 ~]# 

部署dashboard

dashboard是k8s提供的一个可视化操作界面,用于简化我们对集群的操作和管理,在界面上我们可以很方便的查看各种信息、操作Pod、Service等资源,以及创建新的资源等。dashboard的仓库地址如下,

dashboard的部署也比较简单,首先定义dashboard-all.yaml配置文件,内容如下:

apiVersion: v1
kind: Namespace
metadata:
  name: kubernetes-dashboard

---

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard

---

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 8523
  type: NodePort
  selector:
    k8s-app: kubernetes-dashboard

---

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-certs
  namespace: kubernetes-dashboard
type: Opaque

---

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-csrf
  namespace: kubernetes-dashboard
type: Opaque
data:
  csrf: ""

---

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-key-holder
  namespace: kubernetes-dashboard
type: Opaque

---

kind: ConfigMap
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-settings
  namespace: kubernetes-dashboard

---

kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
rules:
  # Allow Dashboard to get, update and delete Dashboard exclusive secrets.
  - apiGroups: [""]
    resources: ["secrets"]
    resourceNames: ["kubernetes-dashboard-key-holder", "kubernetes-dashboard-certs", "kubernetes-dashboard-csrf"]
    verbs: ["get", "update", "delete"]
    # Allow Dashboard to get and update 'kubernetes-dashboard-settings' config map.
  - apiGroups: [""]
    resources: ["configmaps"]
    resourceNames: ["kubernetes-dashboard-settings"]
    verbs: ["get", "update"]
    # Allow Dashboard to get metrics.
  - apiGroups: [""]
    resources: ["services"]
    resourceNames: ["heapster", "dashboard-metrics-scraper"]
    verbs: ["proxy"]
  - apiGroups: [""]
    resources: ["services/proxy"]
    resourceNames: ["heapster", "http:heapster:", "https:heapster:", "dashboard-metrics-scraper", "http:dashboard-metrics-scraper"]
    verbs: ["get"]

---

kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
rules:
  # Allow Metrics Scraper to get metrics from the Metrics server
  - apiGroups: ["metrics.k8s.io"]
    resources: ["pods", "nodes"]
    verbs: ["get", "list", "watch"]

---

apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: kubernetes-dashboard
subjects:
  - kind: ServiceAccount
    name: kubernetes-dashboard
    namespace: kubernetes-dashboard

---

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: kubernetes-dashboard
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: kubernetes-dashboard
subjects:
  - kind: ServiceAccount
    name: kubernetes-dashboard
    namespace: kubernetes-dashboard

---

kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
    spec:
      containers:
        - name: kubernetes-dashboard
          image: kubernetesui/dashboard:v2.0.3
          imagePullPolicy: Always
          ports:
            - containerPort: 8443
              protocol: TCP
          args:
            - --auto-generate-certificates
            - --namespace=kubernetes-dashboard
            # Uncomment the following line to manually specify Kubernetes API server Host
            # If not specified, Dashboard will attempt to auto discover the API server and connect
            # to it. Uncomment only if the default does not work.
            # - --apiserver-host=http://my-address:port
          volumeMounts:
            - name: kubernetes-dashboard-certs
              mountPath: /certs
              # Create on-disk volume to store exec logs
            - mountPath: /tmp
              name: tmp-volume
          livenessProbe:
            httpGet:
              scheme: HTTPS
              path: /
              port: 8443
            initialDelaySeconds: 30
            timeoutSeconds: 30
          securityContext:
            allowPrivilegeEscalation: false
            readOnlyRootFilesystem: true
            runAsUser: 1001
            runAsGroup: 2001
      volumes:
        - name: kubernetes-dashboard-certs
          secret:
            secretName: kubernetes-dashboard-certs
        - name: tmp-volume
          emptyDir: {}
      serviceAccountName: kubernetes-dashboard
      nodeSelector:
        "kubernetes.io/os": linux
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
        - key: node-role.kubernetes.io/master
          effect: NoSchedule

---

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: dashboard-metrics-scraper
  name: dashboard-metrics-scraper
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 8000
      targetPort: 8000
  selector:
    k8s-app: dashboard-metrics-scraper

---

kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: dashboard-metrics-scraper
  name: dashboard-metrics-scraper
  namespace: kubernetes-dashboard
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: dashboard-metrics-scraper
  template:
    metadata:
      labels:
        k8s-app: dashboard-metrics-scraper
      annotations:
        seccomp.security.alpha.kubernetes.io/pod: 'runtime/default'
    spec:
      containers:
        - name: dashboard-metrics-scraper
          image: kubernetesui/metrics-scraper:v1.0.4
          ports:
            - containerPort: 8000
              protocol: TCP
          livenessProbe:
            httpGet:
              scheme: HTTP
              path: /
              port: 8000
            initialDelaySeconds: 30
            timeoutSeconds: 30
          volumeMounts:
          - mountPath: /tmp
            name: tmp-volume
          securityContext:
            allowPrivilegeEscalation: false
            readOnlyRootFilesystem: true
            runAsUser: 1001
            runAsGroup: 2001
      serviceAccountName: kubernetes-dashboard
      nodeSelector:
        "kubernetes.io/os": linux
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
        - key: node-role.kubernetes.io/master
          effect: NoSchedule
      volumes:
        - name: tmp-volume
          emptyDir: {}

创建dashboard服务:

[root@m1 ~]# kubectl create -f dashboard-all.yaml 
namespace/kubernetes-dashboard created
serviceaccount/kubernetes-dashboard created
service/kubernetes-dashboard created
secret/kubernetes-dashboard-certs created
secret/kubernetes-dashboard-csrf created
secret/kubernetes-dashboard-key-holder created
configmap/kubernetes-dashboard-settings created
role.rbac.authorization.k8s.io/kubernetes-dashboard created
clusterrole.rbac.authorization.k8s.io/kubernetes-dashboard created
rolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created
clusterrolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created
deployment.apps/kubernetes-dashboard created
service/dashboard-metrics-scraper created
deployment.apps/dashboard-metrics-scraper created
[root@m1 ~]# 

查看deployment运行情况:

[root@m1 ~]# kubectl get deployment kubernetes-dashboard -n kubernetes-dashboard
NAME                   READY   UP-TO-DATE   AVAILABLE   AGE
kubernetes-dashboard   1/1     1            1           20s
[root@m1 ~]# 

查看dashboard pod运行情况:

[root@m1 ~]# kubectl --namespace kubernetes-dashboard get pods -o wide |grep dashboard
dashboard-metrics-scraper-7b59f7d4df-xzxs8   1/1     Running   0          82s   172.16.217.13   n2     <none>           <none>
kubernetes-dashboard-5dbf55bd9d-s8rhb        1/1     Running   0          82s   172.16.40.132   n1     <none>           <none>
[root@m1 ~]# 

查看dashboard service的运行情况:

[root@m1 ~]# kubectl get services kubernetes-dashboard -n kubernetes-dashboard
NAME                   TYPE       CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes-dashboard   NodePort   10.255.120.138   <none>        443:8523/TCP   101s
[root@m1 ~]# 

n1节点上查看8523端口是否有被正常监听:

[root@n1 ~]# netstat -ntlp |grep 8523
tcp        0      0 0.0.0.0:8523       0.0.0.0:*     LISTEN      13230/kube-proxy    
[root@n1 ~]# 

访问dashboard

为了集群安全,从 1.7 开始,dashboard 只允许通过 https 访问,我们使用NodePort的方式暴露服务,可以使用 https://NodeIP:NodePort 地址访问。例如使用curl进行访问:

[root@n1 ~]# curl https://192.168.243.146:8523 -k
<!--
Copyright 2017 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->

<!doctype html>
<html lang="en">

<head>
  <meta charset="utf-8">
  <title>Kubernetes Dashboard</title>
  <link rel="icon"
        type="image/png"
        href="assets/images/kubernetes-logo.png" />
  <meta name="viewport"
        content="width=device-width">
<link rel="stylesheet" href="styles.988f26601cdcb14da469.css"></head>

<body>
  <kd-root></kd-root>
<script src="runtime.ddfec48137b0abfd678a.js" defer></script><script src="polyfills-es5.d57fe778f4588e63cc5c.js" nomodule defer></script><script src="polyfills.49104fe38e0ae7955ebb.js" defer></script><script src="scripts.391d299173602e261418.js" defer></script><script src="main.b94e335c0d02b12e3a7b.js" defer></script></body>

</html>
[root@n1 ~]# 
  • 由于dashboard的证书是自签的,所以这里需要加-k参数指定不验证证书进行https请求

关于自定义证书

默认dashboard的证书是自动生成的,肯定是非安全的证书,如果大家有域名和对应的安全证书可以自己替换掉。使用安全的域名方式访问dashboard。

dashboard-all.yaml中增加dashboard启动参数,可以指定证书文件,其中证书文件是通过secret注进来的。

- --tls-cert-file=dashboard.cer
- --tls-key-file=dashboard.key

登录dashboard

Dashboard 默认只支持 token 认证,所以如果使用 KubeConfig 文件,需要在该文件中指定 token,我们这里使用token的方式登录。

首先创建service account:

[root@m1 ~]# kubectl create sa dashboard-admin -n kube-system
serviceaccount/dashboard-admin created
[root@m1 ~]#

创建角色绑定关系:

[root@m1 ~]# kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
clusterrolebinding.rbac.authorization.k8s.io/dashboard-admin created
[root@m1 ~]# 

查看dashboard-admin的Secret名称:

[root@m1 ~]# kubectl get secrets -n kube-system | grep dashboard-admin | awk '{print $1}'
dashboard-admin-token-757fb
[root@m1 ~]# 

打印Secret的token:

[root@m1 ~]# ADMIN_SECRET=$(kubectl get secrets -n kube-system | grep dashboard-admin | awk '{print $1}')
[root@m1 ~]# kubectl describe secret -n kube-system ${ADMIN_SECRET} | grep -E '^token' | awk '{print $2}'
eyJhbGciOiJSUzI1NiIsImtpZCI6Ilhyci13eDR3TUtmSG9kcXJxdzVmcFdBTFBGeDhrOUY2QlZoenZhQWVZM0EifQ.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.UlKmcZoGb6OQ1jE55oShAA2dBiL0FHEcIADCfTogtBEuYLPdJtBUVQZ_aVICGI23gugIu6Y9Yt7iQYlwT6zExhUzDz0UUiBT1nSLe94CkPl64LXbeWkC3w2jee8iSqR2UfIZ4fzY6azaqhGKE1Fmm_DLjD-BS-etphOIFoCQFbabuFjvR8DVDss0z1czhHwXEOvlv5ted00t50dzv0rAZ8JN-PdOoem3aDkXDvWWmqu31QAhqK1strQspbUOF5cgcSeGwsQMfau8U5BNsm_K92IremHqOVvOinkR_EHslomDJRc3FYbV_Jw359rc-QROSTbLphRfvGNx9UANDMo8lA
[root@m1 ~]# 

获取到token后,使用浏览器访问https://192.168.243.146:8523,由于是dashboard是自签的证书,所以此时浏览器会提示警告。不用理会直接点击“高级” -> “继续前往”即可:

image.png

然后输入token:


image.png

成功登录后首页如下:


image.png

可视化界面也没啥可说的,这里就不进一步介绍了,可以自行探索一下。我们使用二进制方式搭建高可用的k8s集群之旅至此就结束了,本文篇幅可以说是非常的长,这也是为了记录每一步的操作细节,所以为了方便还是使用kubeadm吧。

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