Centos7系统二进制安装Kubernetes（v1.20）集群

一、环境准备

参考：https://www.cnblogs.com/Mr-Ding/p/17773745.html

二、部署ETCD集群

2.1、准备cfssl证书生成工具

cd k8s1.20二进制包/
chmod +x cfssl_linux-amd64 cfssljson_linux-amd64 cfssl-certinfo_linux-amd64
mv cfssl_linux-amd64 /usr/local/bin/cfssl
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson
mv cfssl-certinfo_linux-amd64 /usr/bin/cfssl-certinfo

2.2、生成Etcd证书

2.2.1、之前证书颁发机构(CA)

mkdir -p ~/TLS/{etcd,k8s}
 
cd ~/TLS/etcd

自签CA：

cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "www": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF
 
cat > ca-csr.json << EOF
{
    "CN": "etcd CA",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing"
        }
    ]
}
EOF

生成证书：

cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

会生成ca.pem和ca-key.pem文件

2.2.2、使用自签CA签发Etcd HTTPS证书

创建证书申请文件：

cat > server-csr.json << EOF
{
    "CN": "etcd",
    "hosts": [
    "192.168.100.31",
    "192.168.100.33",
    "192.168.100.34",
    "192.168.100.38",
    "192.168.100.39"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing"
        }
    ]
}
EOF

注：上述文件hosts字段中IP为所有etcd节点的集群内部通信IP，一个都不能少！为了方便后期扩容可以多写几个预留的IP。

生成证书：

cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=www server-csr.json | cfssljson -bare server

 会生成server.pem和server-key.pem文件。

2.3、部署ETCD集群

以下在master1节点上操作，为简化操作，待会将master1节点生成的所有文件拷贝到node1节点和node2节点.

 2.3.1、创建工作目录并解压二进制包

cd ~/k8s1.20二进制包/
mkdir /opt/etcd/{bin,cfg,ssl} -p
tar zxvf etcd-v3.4.9-linux-amd64.tar.gz
mv etcd-v3.4.9-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

 2.3.2、创建etcd配置文件

cat > /opt/etcd/cfg/etcd.conf << EOF
#[Member]
ETCD_NAME="etcd-1"
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.100.31:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.100.31:2379"
 
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.100.31:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.100.31:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.100.31:2380,etcd-2=https://192.168.100.33:2380,etcd-3=https://192.168.100.34:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF

• ETCD_NAME：节点名称，集群中唯一
• ETCD_DATA_DIR：数据目录
• ETCD_LISTEN_PEER_URLS：集群通信监听地址
• ETCD_LISTEN_CLIENT_URLS：客户端访问监听地址
• ETCD_INITIAL_ADVERTISE_PEERURLS：集群通告地址
• ETCD_ADVERTISE_CLIENT_URLS：客户端通告地址
• ETCD_INITIAL_CLUSTER：集群节点地址
• ETCD_INITIALCLUSTER_TOKEN：集群Token
• ETCD_INITIALCLUSTER_STATE：加入集群的当前状态，new是新集群，existing表示加入已有集群

2.3.3、systemd管理etcd

cat > /usr/lib/systemd/system/etcd.service << EOF
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target
 
[Service]
Type=notify
EnvironmentFile=/opt/etcd/cfg/etcd.conf
ExecStart=/opt/etcd/bin/etcd \
--cert-file=/opt/etcd/ssl/server.pem \
--key-file=/opt/etcd/ssl/server-key.pem \
--peer-cert-file=/opt/etcd/ssl/server.pem \
--peer-key-file=/opt/etcd/ssl/server-key.pem \
--trusted-ca-file=/opt/etcd/ssl/ca.pem \
--peer-trusted-ca-file=/opt/etcd/ssl/ca.pem \
--logger=zap
Restart=on-failure
LimitNOFILE=65536
 
[Install]
WantedBy=multi-user.target
EOF

2.3.4、拷贝刚才生成的证书

把刚才生成的证书拷贝到配置文件中的路径：

cp ~/TLS/etcd/ca*pem ~/TLS/etcd/server*pem /opt/etcd/ssl/

2.3.5、将上面master1节点所有生成的文件拷贝到node1节点和node2节点

scp -r /opt/etcd/ root@192.168.100.33:/opt/
scp /usr/lib/systemd/system/etcd.service root@192.168.100.33:/usr/lib/systemd/system/
scp -r /opt/etcd/ root@192.168.100.34:/opt/
scp /usr/lib/systemd/system/etcd.service root@192.168.100.34:/usr/lib/systemd/system/

然后在node1节点和node2节点分别修改etcd.conf配置文件中的节点名称和当前服务器IP：

vi /opt/etcd/cfg/etcd.conf
#[Member]
ETCD_NAME="etcd-2"   # 修改此处，node1改为etcd-2，node2改为etcd-3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.100.33:2380"   # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://192.168.100.33:2379" # 修改此处为当前服务器IP
 
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.100.33:2380" # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.100.33:2379" # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://192.168.100.31:2380,etcd-2=https://192.168.100.33:2380,etcd-3=https://192.168.100.34:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

最后启动etcd并设置开机启动

systemctl daemon-reload
systemctl start etcd
systemctl enable etcd

2.3.6、查看集群状态

ETCDCTL_API=3 /opt/etcd/bin/etcdctl --cacert=/opt/etcd/ssl/ca.pem --cert=/opt/etcd/ssl/server.pem --key=/opt/etcd/ssl/server-key.pem --endpoints="https://192.168.100.31:2379,https://192.168.100.33:2379,https://192.168.100.34:2379" endpoint health --write-out=table
+-----------------------------+--------+-------------+-------+
|          ENDPOINT           | HEALTH |    TOOK     | ERROR |
+-----------------------------+--------+-------------+-------+
| https://192.168.100.31:2379 |   true |  7.213794ms |       |
| https://192.168.100.34:2379 |   true | 36.612749ms |       |
| https://192.168.100.33:2379 |   true | 35.594508ms |       |
+-----------------------------+--------+-------------+-------+

三、安装docker

3.1、解压二进制包

tar zxvf docker-19.03.9.tgz
mv docker/* /usr/bin

3.2、systemd管理docker

cat > /usr/lib/systemd/system/docker.service << EOF
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target
 
[Service]
Type=notify
ExecStart=/usr/bin/dockerd
ExecReload=/bin/kill -s HUP $MAINPID
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TimeoutStartSec=0
Delegate=yes
KillMode=process
Restart=on-failure
StartLimitBurst=3
StartLimitInterval=60s
 
[Install]
WantedBy=multi-user.target
EOF

3.3、创建配置文件

mkdir /etc/docker
cat > /etc/docker/daemon.json << EOF
{
  "registry-mirrors": ["https://b9pmyelo.mirror.aliyuncs.com"]
}
EOF

3.4、启动并设为开机自启

systemctl daemon-reload
systemctl start docker
systemctl enable docker

3.5、node1和node2安装docker

#发送docker二进制包到node1和node2服务器
[root@k8s-master1 ~/k8s1.20二进制包]# scp docker-19.03.9.tgz 192.168.100.33:/root
docker-19.03.9.tgz                                                    100%   58MB 114.2MB/s   00:00    
[root@k8s-master1 ~/k8s1.20二进制包]# scp docker-19.03.9.tgz 192.168.100.34:/root
docker-19.03.9.tgz                                                    100%   58MB 118.1MB/s   00:00 
 
#创建/etc/docker目录
mkdir /etc/docker
 
#在node1和node2上分别解压docker二进制包
tar zxvf docker-19.03.9.tgz
mv docker/* /usr/bin
 
#把master1上的docker配置文件分别发送到node1和node2上
[root@k8s-master1 ~/k8s1.20二进制包]# scp /etc/docker/daemon.json 192.168.100.33:/etc/docker/
daemon.json                                                           100%   67    64.0KB/s   00:00    
[root@k8s-master1 ~/k8s1.20二进制包]# scp /usr/lib/systemd/system/docker.service 192.168.100.33:/usr/lib/systemd/system/
docker.service                                                        100%  452   424.5KB/s   00:00    
[root@k8s-master1 ~/k8s1.20二进制包]# scp /etc/docker/daemon.json 192.168.100.34:/etc/docker/
daemon.json                                                           100%   67    65.2KB/s   00:00    
[root@k8s-master1 ~/k8s1.20二进制包]# scp /usr/lib/systemd/system/docker.service 192.168.100.34:/usr/lib/systemd/system/
docker.service                                                        100%  452   511.3KB/s   00:00 
 
#在node1和node2上启动docker服务并设为开机自启
systemctl daemon-reload
systemctl start docker
systemctl enable docker

四、部署Master Node

 4.1、生成kube-apiserver证书

 4.1.1、自签证书颁发机构（CA）

cd ~/TLS/k8s
 
cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF
cat > ca-csr.json << EOF
{
    "CN": "kubernetes",
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "Beijing",
            "ST": "Beijing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
EOF

生成证书：

cfssl gencert -initca ca-csr.json | cfssljson -bare ca -

会生成ca.pem和ca-key.pem文件。

4.1.2、使用自签CA签发kube-apiserver HTTPS证书

创建证书申请文件：

cat > server-csr.json << EOF
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "127.0.0.1",
      "192.168.100.31",
      "192.168.100.33",
      "192.168.100.34",
      "192.168.100.37",
      "192.168.100.38",
      "192.168.100.39",
      "kubernetes",
      "kubernetes.default",
      "kubernetes.default.svc",
      "kubernetes.default.svc.cluster",
      "kubernetes.default.svc.cluster.local"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing",
            "O": "k8s",
            "OU": "System"
        }
    ]
}
EOF

注：上述文件hosts字段中IP为所有Master/LB/VIP IP，一个都不能少！为了方便后期扩容可以多写几个预留的IP。

生成证书：

cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes server-csr.json | cfssljson -bare serve

会生成server.pem和server-key.pem文件。

4.1.3、解压二进制包 

cd ~/k8s1.20二进制包/
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 
tar zxvf kubernetes-server-linux-amd64.tar.gz
cd kubernetes/server/bin
cp kube-apiserver kube-scheduler kube-controller-manager /opt/kubernetes/bin
cp kubectl /usr/bin/

4.2、部署kube-apiserver

cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
KUBE_APISERVER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--etcd-servers=https://192.168.100.31:2379,https://192.168.100.33:2379,https://192.168.100.34:2379 \\
--bind-address=192.168.100.31 \\
--secure-port=6443 \\
--advertise-address=192.168.100.31 \\
--allow-privileged=true \\
--service-cluster-ip-range=10.0.0.0/24 \\
--enable-admission-plugins=NamespaceLifecycle,LimitRanger,ServiceAccount,ResourceQuota,NodeRestriction \\
--authorization-mode=RBAC,Node \\
--enable-bootstrap-token-auth=true \\
--token-auth-file=/opt/kubernetes/cfg/token.csv \\
--service-node-port-range=30000-32767 \\
--kubelet-client-certificate=/opt/kubernetes/ssl/server.pem \\
--kubelet-client-key=/opt/kubernetes/ssl/server-key.pem \\
--tls-cert-file=/opt/kubernetes/ssl/server.pem  \\
--tls-private-key-file=/opt/kubernetes/ssl/server-key.pem \\
--client-ca-file=/opt/kubernetes/ssl/ca.pem \\
--service-account-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--service-account-issuer=api \\
--service-account-signing-key-file=/opt/kubernetes/ssl/server-key.pem \\
--etcd-cafile=/opt/etcd/ssl/ca.pem \\
--etcd-certfile=/opt/etcd/ssl/server.pem \\
--etcd-keyfile=/opt/etcd/ssl/server-key.pem \\
--requestheader-client-ca-file=/opt/kubernetes/ssl/ca.pem \\
--proxy-client-cert-file=/opt/kubernetes/ssl/server.pem \\
--proxy-client-key-file=/opt/kubernetes/ssl/server-key.pem \\
--requestheader-allowed-names=kubernetes \\
--requestheader-extra-headers-prefix=X-Remote-Extra- \\
--requestheader-group-headers=X-Remote-Group \\
--requestheader-username-headers=X-Remote-User \\
--enable-aggregator-routing=true \\
--audit-log-maxage=30 \\
--audit-log-maxbackup=3 \\
--audit-log-maxsize=100 \\
--audit-log-path=/opt/kubernetes/logs/k8s-audit.log"
EOF

注：上面两个\ \ 第一个是转义符，第二个是换行符，使用转义符是为了使用EOF保留换行符。

• --logtostderr：启用日志
• ---v：日志等级
• --log-dir：日志目录
• --etcd-servers：etcd集群地址
• --bind-address：监听地址
• --secure-port：https安全端口
• --advertise-address：集群通告地址
• --allow-privileged：启用授权
• --service-cluster-ip-range：Service虚拟IP地址段
• --enable-admission-plugins：准入控制模块
• --authorization-mode：认证授权，启用RBAC授权和节点自管理
• --enable-bootstrap-token-auth：启用TLS bootstrap机制
• --token-auth-file：bootstrap token文件
• --service-node-port-range：Service nodeport类型默认分配端口范围
• --kubelet-client-xxx：apiserver访问kubelet客户端证书
• --tls-xxx-file：apiserver https证书
• 20版本必须加的参数：--service-account-issuer，--service-account-signing-key-file
• --etcd-xxxfile：连接Etcd集群证书
• --audit-log-xxx：审计日志
• 启动聚合层相关配置：--requestheader-client-ca-file，--proxy-client-cert-file，--proxy-client-key-file，--requestheader-allowed-names，--requestheader-extra-headers-prefix，--requestheader-group-headers，--requestheader-username-headers，--enable-aggregator-routing

4.2.1、拷贝刚才生成的证书

把刚才生成的证书拷贝到配置文件中的路径：

cp ~/TLS/k8s/ca*pem ~/TLS/k8s/server*pem /opt/kubernetes/ssl/

4.2.2、启用 TLS Bootstrapping 机制

TLS Bootstraping：Master apiserver启用TLS认证后，Node节点kubelet和kube-proxy要与kube-apiserver进行通信，必须使用CA签发的有效证书才可以，当Node节点很多时，这种客户端证书颁发需要大量工作，同样也会增加集群扩展复杂度。为了简化流程，Kubernetes引入了TLS bootstraping机制来自动颁发客户端证书，kubelet会以一个低权限用户自动向apiserver申请证书，kubelet的证书由apiserver动态签署。所以强烈建议在Node上使用这种方式，目前主要用于kubelet，kube-proxy还是由我们统一颁发一个证书。

TLS bootstraping 工作流程：

创建上述配置文件中token文件：

cat > /opt/kubernetes/cfg/token.csv << EOF
c47ffb939f5ca36231d9e3121a252940,kubelet-bootstrap,10001,"system:node-bootstrapper"
EOF

格式：token，用户名，UID，用户组

token也可自行生成替换：

head -c 16 /dev/urandom | od -An -t x | tr -d ' '

4.2.3、systemd管理apiserver

cat > /usr/lib/systemd/system/kube-apiserver.service << EOF
[Unit]
Description=Kubernetes API Server
Documentation=https://github.com/kubernetes/kubernetes
 
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-apiserver.conf
ExecStart=/opt/kubernetes/bin/kube-apiserver \$KUBE_APISERVER_OPTS
Restart=on-failure
 
[Install]
WantedBy=multi-user.target
EOF

4.2.4、启动并设置开机启动

systemctl daemon-reload
systemctl start kube-apiserver 
systemctl enable kube-apiserver

4.3、部署kube-controller-manager

4.3.1、创建配置文件

cat > /opt/kubernetes/cfg/kube-controller-manager.conf << EOF
KUBE_CONTROLLER_MANAGER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--leader-elect=true \\
--kubeconfig=/opt/kubernetes/cfg/kube-controller-manager.kubeconfig \\
--bind-address=127.0.0.1 \\
--allocate-node-cidrs=true \\
--cluster-cidr=10.244.0.0/16 \\
--service-cluster-ip-range=10.0.0.0/24 \\
--cluster-signing-cert-file=/opt/kubernetes/ssl/ca.pem \\
--cluster-signing-key-file=/opt/kubernetes/ssl/ca-key.pem  \\
--root-ca-file=/opt/kubernetes/ssl/ca.pem \\
--service-account-private-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--cluster-signing-duration=87600h0m0s"
EOF

• --kubeconfig：连接apiserver配置文件
• --leader-elect：当该组件启动多个时，自动选举（HA）
• --cluster-signing-cert-file/--cluster-signing-key-file：自动为kubelet颁发证书的CA，与apiserver保持一致

4.3.2、生成kubeconfig文件

生成kube-controller-manager证书：

# 切换工作目录
cd ~/TLS/k8s
 
# 创建证书请求文件
cat > kube-controller-manager-csr.json << EOF
{
  "CN": "system:kube-controller-manager",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "BeiJing", 
      "ST": "BeiJing",
      "O": "system:masters",
      "OU": "System"
    }
  ]
}
EOF
 
# 生成证书
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-controller-manager-csr.json | cfssljson -bare kube-controller-manager

生成kubeconfig文件（以下是shell命令，直接在终端执行）：

KUBE_CONFIG="/opt/kubernetes/cfg/kube-controller-manager.kubeconfig"
KUBE_APISERVER="https://192.168.100.31:6443"
 
kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials kube-controller-manager \
  --client-certificate=./kube-controller-manager.pem \
  --client-key=./kube-controller-manager-key.pem \
  --embed-certs=true \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-controller-manager \
  --kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

4.3.3、systemd管理controller-manager

cat > /usr/lib/systemd/system/kube-controller-manager.service << EOF
[Unit]
Description=Kubernetes Controller Manager
Documentation=https://github.com/kubernetes/kubernetes
 
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-controller-manager.conf
ExecStart=/opt/kubernetes/bin/kube-controller-manager \$KUBE_CONTROLLER_MANAGER_OPTS
Restart=on-failure
 
[Install]
WantedBy=multi-user.target
EOF

4.3.4、启动并设置开机启动

systemctl daemon-reload
systemctl start kube-controller-manager
systemctl enable kube-controller-manager

4.4、部署kube-scheduler

4.4.1、创建配置文件

cat > /opt/kubernetes/cfg/kube-scheduler.conf << EOF
KUBE_SCHEDULER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--leader-elect \\
--kubeconfig=/opt/kubernetes/cfg/kube-scheduler.kubeconfig \\
--bind-address=127.0.0.1"
EOF

• --kubeconfig：连接apiserver配置文件
• --leader-elect：当该组件启动多个时，自动选举（HA）

4.4.2、生成kubeconfig文件

生成kube-scheduler证书：

# 切换工作目录
cd ~/TLS/k8s
 
# 创建证书请求文件
cat > kube-scheduler-csr.json << EOF
{
  "CN": "system:kube-scheduler",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "BeiJing",
      "ST": "BeiJing",
      "O": "system:masters",
      "OU": "System"
    }
  ]
}
EOF
 
# 生成证书
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-scheduler-csr.json | cfssljson -bare kube-scheduler

生成kubeconfig文件（以下是shell命令，直接在终端执行）：

KUBE_CONFIG="/opt/kubernetes/cfg/kube-scheduler.kubeconfig"
KUBE_APISERVER="https://192.168.100.31:6443"
 
kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials kube-scheduler \
  --client-certificate=./kube-scheduler.pem \
  --client-key=./kube-scheduler-key.pem \
  --embed-certs=true \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-scheduler \
  --kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

4.4.3、systemd管理scheduler

cat > /usr/lib/systemd/system/kube-scheduler.service << EOF
[Unit]
Description=Kubernetes Scheduler
Documentation=https://github.com/kubernetes/kubernetes
 
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-scheduler.conf
ExecStart=/opt/kubernetes/bin/kube-scheduler \$KUBE_SCHEDULER_OPTS
Restart=on-failure
 
[Install]
WantedBy=multi-user.target
EOF

4.4.4、启动并设置开机启动

systemctl daemon-reload
systemctl start kube-scheduler
systemctl enable kube-scheduler

4.4.5、查看集群状态

生成kubectl连接集群的证书：

cat > admin-csr.json <<EOF
{
  "CN": "admin",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "BeiJing",
      "ST": "BeiJing",
      "O": "system:masters",
      "OU": "System"
    }
  ]
}
EOF
 
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes admin-csr.json | cfssljson -bare admin

生成kubeconfig文件：

mkdir /root/.kube
 
KUBE_CONFIG="/root/.kube/config"
KUBE_APISERVER="https://192.168.100.31:6443"
 
kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials cluster-admin \
  --client-certificate=./admin.pem \
  --client-key=./admin-key.pem \
  --embed-certs=true \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
  --cluster=kubernetes \
  --user=cluster-admin \
  --kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

通过kubectl工具查看当前集群组件状态：

kubectl get cs
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
controller-manager   Healthy   ok                  
etcd-0               Healthy   {"health":"true"}   
etcd-1               Healthy   {"health":"true"}   
etcd-2               Healthy   {"health":"true"}   

如上输出说明Master节点组件运行正常。

4.4.6、授权kubelet-bootstrap用户允许请求证书

kubectl create clusterrolebinding kubelet-bootstrap \
--clusterrole=system:node-bootstrapper \
--user=kubelet-bootstrap

 五、部署Worker Node

下面还是在Master Node上操作，即同时作为Worker Node

 5.1、创建工作目录并拷贝二进制文件

在所有worker node创建工作目录：

mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 

从master节点拷贝：

cd ~/k8s1.20二进制包/kubernetes/server/bin/
cp kubelet kube-proxy /opt/kubernetes/bin   # 本地拷贝

 5.2、部署kubelet

 5.2.1、创建配置文件

cat > /opt/kubernetes/cfg/kubelet.conf << EOF
KUBELET_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--hostname-override=k8s-master1 \\
--network-plugin=cni \\
--kubeconfig=/opt/kubernetes/cfg/kubelet.kubeconfig \\
--bootstrap-kubeconfig=/opt/kubernetes/cfg/bootstrap.kubeconfig \\
--config=/opt/kubernetes/cfg/kubelet-config.yml \\
--cert-dir=/opt/kubernetes/ssl \\
--pod-infra-container-image=lizhenliang/pause-amd64:3.0"
EOF

• --hostname-override：显示名称，集群中唯一
• --network-plugin：启用CNI
• --kubeconfig：空路径，会自动生成，后面用于连接apiserver
• --bootstrap-kubeconfig：首次启动向apiserver申请证书
• --config：配置参数文件
• --cert-dir：kubelet证书生成目录
• --pod-infra-container-image：管理Pod网络容器的镜像

5.2.2、配置参数文件

cat > /opt/kubernetes/cfg/kubelet-config.yml << EOF
kind: KubeletConfiguration
apiVersion: kubelet.config.k8s.io/v1beta1
address: 0.0.0.0
port: 10250
readOnlyPort: 10255
cgroupDriver: cgroupfs
clusterDNS:
- 10.0.0.2
clusterDomain: cluster.local 
failSwapOn: false
authentication:
  anonymous:
    enabled: false
  webhook:
    cacheTTL: 2m0s
    enabled: true
  x509:
    clientCAFile: /opt/kubernetes/ssl/ca.pem 
authorization:
  mode: Webhook
  webhook:
    cacheAuthorizedTTL: 5m0s
    cacheUnauthorizedTTL: 30s
evictionHard:
  imagefs.available: 15%
  memory.available: 100Mi
  nodefs.available: 10%
  nodefs.inodesFree: 5%
maxOpenFiles: 1000000
maxPods: 110
EOF

5.2.3、生成kubelet初次加入集群引导kubeconfig文件

KUBE_CONFIG="/opt/kubernetes/cfg/bootstrap.kubeconfig"
KUBE_APISERVER="https://192.168.100.31:6443" # apiserver IP:PORT
TOKEN="c47ffb939f5ca36231d9e3121a252940" # 与token.csv里保持一致
 
# 生成 kubelet bootstrap kubeconfig 配置文件
kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials "kubelet-bootstrap" \
  --token=${TOKEN} \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
  --cluster=kubernetes \
  --user="kubelet-bootstrap" \
  --kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

5.2.4、 systemd管理kubelet

cat > /usr/lib/systemd/system/kubelet.service << EOF
[Unit]
Description=Kubernetes Kubelet
After=docker.service
 
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kubelet.conf
ExecStart=/opt/kubernetes/bin/kubelet \$KUBELET_OPTS
Restart=on-failure
LimitNOFILE=65536
 
[Install]
WantedBy=multi-user.target
EOF

 5.2.5、启动并设置开机启动

systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet

 5.3、批准kubelet证书申请并加入集群

# 查看kubelet证书请求
kubectl get csr
 
# 批准申请
kubectl certificate approve node-csr-90owPFh_jzfvsORKhMainlK2LX00cskbCCRjVJDimek
certificatesigningrequest.certificates.k8s.io/node-csr-90owPFh_jzfvsORKhMainlK2LX00cskbCCRjVJDimek approved
 
# 查看节点
kubectl get node
NAME          STATUS     ROLES    AGE   VERSION
k8s-master1   NotReady   <none>   20s   v1.20.15

注：由于网络插件还没有部署，节点会没有准备就绪 NotReady

5.4、 部署kube-proxy

 5.4.1、创建配置文件

cat > /opt/kubernetes/cfg/kube-proxy.conf << EOF
KUBE_PROXY_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--config=/opt/kubernetes/cfg/kube-proxy-config.yml"
EOF

5.4.2、配置参数文件

cat > /opt/kubernetes/cfg/kube-proxy-config.yml << EOF
kind: KubeProxyConfiguration
apiVersion: kubeproxy.config.k8s.io/v1alpha1
bindAddress: 0.0.0.0
metricsBindAddress: 0.0.0.0:10249
clientConnection:
  kubeconfig: /opt/kubernetes/cfg/kube-proxy.kubeconfig
hostnameOverride: k8s-master1
clusterCIDR: 10.0.0.0/24
EOF

5.4.3、生成kube-proxy.kubeconfig文件

生成kube-proxy证书：

# 切换工作目录
cd ~/TLS/k8s
 
# 创建证书请求文件
cat > kube-proxy-csr.json << EOF
{
  "CN": "system:kube-proxy",
  "hosts": [],
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "L": "BeiJing",
      "ST": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ]
}
EOF
 
# 生成证书
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kube-proxy-csr.json | cfssljson -bare kube-proxy
 
#生成kubeconfig文件：
KUBE_CONFIG="/opt/kubernetes/cfg/kube-proxy.kubeconfig"
KUBE_APISERVER="https://192.168.100.31:6443"
 
kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-credentials kube-proxy \
  --client-certificate=./kube-proxy.pem \
  --client-key=./kube-proxy-key.pem \
  --embed-certs=true \
  --kubeconfig=${KUBE_CONFIG}
kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-proxy \
  --kubeconfig=${KUBE_CONFIG}
kubectl config use-context default --kubeconfig=${KUBE_CONFIG}

5.4.4、systemd管理kube-proxy

cat > /usr/lib/systemd/system/kube-proxy.service << EOF
[Unit]
Description=Kubernetes Proxy
After=network.target
 
[Service]
EnvironmentFile=/opt/kubernetes/cfg/kube-proxy.conf
ExecStart=/opt/kubernetes/bin/kube-proxy \$KUBE_PROXY_OPTS
Restart=on-failure
LimitNOFILE=65536
 
[Install]
WantedBy=multi-user.target
EOF

5.4.5、启动并设置开机启动

systemctl daemon-reload
systemctl start kube-proxy
systemctl enable kube-proxy

5.5、部署网络组件

Calico是一个纯三层的数据中心网络方案，是目前Kubernetes主流的网络方案。

部署Calico：

cd ~/k8s1.20二进制包/
kubectl apply -f calico.yaml
kubectl get pods -n kube-system

等Calico Pod都Running，节点也会准备就绪：

kubectl get node
NAME          STATUS   ROLES    AGE     VERSION
k8s-master1   Ready    <none>   8m16s   v1.20.15

5.6、授权apiserver访问kubelet

应用场景：例如kubectl logs

cat > apiserver-to-kubelet-rbac.yaml << EOF
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  annotations:
    rbac.authorization.kubernetes.io/autoupdate: "true"
  labels:
    kubernetes.io/bootstrapping: rbac-defaults
  name: system:kube-apiserver-to-kubelet
rules:
  - apiGroups:
      - ""
    resources:
      - nodes/proxy
      - nodes/stats
      - nodes/log
      - nodes/spec
      - nodes/metrics
      - pods/log
    verbs:
      - "*"
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: system:kube-apiserver
  namespace: ""
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:kube-apiserver-to-kubelet
subjects:
  - apiGroup: rbac.authorization.k8s.io
    kind: User
    name: kubernetes
EOF
 
kubectl apply -f apiserver-to-kubelet-rbac.yaml

5.7、新增加Worker Node

5.7.1、拷贝已部署好的Node相关文件到新节点

在Master节点将Worker Node涉及文件拷贝到新节点192.168.100.33/34

scp -r /opt/kubernetes root@192.168.100.33:/opt/
 
scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@192.168.100.33:/usr/lib/systemd/system
 
scp /opt/kubernetes/ssl/ca.pem root@192.168.100.33:/opt/kubernetes/ssl
 
scp -r /opt/kubernetes root@192.168.100.34:/opt/
 
scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@192.168.100.34:/usr/lib/systemd/system
 
scp /opt/kubernetes/ssl/ca.pem root@192.168.100.34:/opt/kubernetes/ssl

5.7.2、删除node1和node2上的kubelet证书和kubeconfig文件 

rm -f /opt/kubernetes/cfg/kubelet.kubeconfig 
rm -f /opt/kubernetes/ssl/kubelet*

注：这几个文件是证书申请审批后自动生成的，每个Node不同，必须删除

5.7.3、修改主机名

vim /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-node1
 
vim /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-node1

5.7.4、启动并设置开机启动 

systemctl daemon-reload
systemctl start kubelet kube-proxy
systemctl enable kubelet kube-proxy

5.7.5、在Master上批准新Node kubelet证书申请 

# 查看证书请求
kubectl get csr
NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-90owPFh_jzfvsORKhMainlK2LX00cskbCCRjVJDimek   14m   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Approved,Issued
node-csr-QywBMN5SRo4Z_uEfhg7iGGi7WmQYwRRk2QONotvVD40   22s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending
node-csr-SMVpcDibRFKaqN-YOdXsy4poLTAhddMt2GjMwp-Ovrc   27s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending
 
# 授权请求
kubectl certificate approve node-csr-QywBMN5SRo4Z_uEfhg7iGGi7WmQYwRRk2QONotvVD40
 
kubectl certificate approve node-csr-SMVpcDibRFKaqN-YOdXsy4poLTAhddMt2GjMwp-Ovrc

5.7.6、查看Node状态

kubectl get node
NAME          STATUS   ROLES    AGE   VERSION
k8s-master1   Ready    <none>   15m   v1.20.15
k8s-node1     Ready    <none>   73s   v1.20.15
k8s-node2     Ready    <none>   82s   v1.20.15

 Node2（192.168.100.34 ）节点同上。记得修改主机名！

 六、部署Dashboard和CoreDNS

 6.1、部署Dashboard

kubectl apply -f kubernetes-dashboard.yaml
 
# 查看部署
kubectl get pods,svc -n kubernetes-dashboard
NAME                                             READY   STATUS              RESTARTS   AGE
pod/dashboard-metrics-scraper-7445d59dfd-flbwm   0/1     ContainerCreating   0          9s
pod/kubernetes-dashboard-5ddcdf9c99-rrfh8        0/1     ContainerCreating   0          9s
 
NAME                                TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)         AGE
service/dashboard-metrics-scraper   ClusterIP   10.0.0.129   <none>        8000/TCP        4m2s
service/kubernetes-dashboard        NodePort    10.0.0.144   <none>        443:30001/TCP   4m2s

访问地址：https://NodeIP:30001

创建service account并绑定默认cluster-admin管理员集群角色：

kubectl create serviceaccount dashboard-admin -n kube-system
kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kube-system:dashboard-admin
kubectl describe secrets -n kube-system $(kubectl -n kube-system get secret | awk '/dashboard-admin/{print $1}')

使用输出的token登录Dashboard

6.2、部署CoreDNS

CoreDNS用于集群内部Service名称解析。

kubectl apply -f 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
 
kubectl get pods -n kube-system
NAME                                       READY   STATUS              RESTARTS   AGE
calico-kube-controllers-577f77cb5c-s26rc   1/1     Running             0          22m
calico-node-6vrjv                          1/1     Running             0          12m
calico-node-npr8n                          1/1     Running             0          13m
calico-node-wj4jw                          1/1     Running             0          22m
coredns-6cc56c94bd-cwktc                   0/1     ContainerCreating   0          7s

DNS解析测试：

kubectl run -it --rm dns-test --image=busybox:1.28.4 sh 
If you don't see a command prompt, try pressing enter.
/ # nslookup kubernetes
Server:    10.0.0.2
Address 1: 10.0.0.2 kube-dns.kube-system.svc.cluster.local
 
Name:      kubernetes
Address 1: 10.0.0.1 kubernetes.default.svc.cluster.local

解析没问题。

至此一个单Master集群就搭建完成了！这个环境就足以满足学习实验了，如果你的服务器配置较高，可继续扩容多Master集群！

七、扩容多Master（高可用架构）

Kubernetes作为容器集群系统，通过健康检查+重启策略实现了Pod故障自我修复能力，通过调度算法实现将Pod分布式部署，并保持预期副本数，根据Node失效状态自动在其他Node拉起Pod，实现了应用层的高可用性。

针对Kubernetes集群，高可用性还应包含以下两个层面的考虑：Etcd数据库的高可用性和Kubernetes Master组件的高可用性。 而Etcd我们已经采用3个节点组建集群实现高可用，本节将对Master节点高可用进行说明和实施。

Master节点扮演着总控中心的角色，通过不断与工作节点上的Kubelet和kube-proxy进行通信来维护整个集群的健康工作状态。如果Master节点故障，将无法使用kubectl工具或者API做任何集群管理。

Master节点主要有三个服务kube-apiserver、kube-controller-manager和kube-scheduler，其中kube-controller-manager和kube-scheduler组件自身通过选择机制已经实现了高可用，所以Master高可用主要针对kube-apiserver组件，而该组件是以HTTP API提供服务，因此对他高可用与Web服务器类似，增加负载均衡器对其负载均衡即可，并且可水平扩容。

7.1、部署Master2 Node

现在需要再增加一台新服务器，作为Master2 Node，IP是192.168.100.32。

为了节省资源你也可以将之前部署好的Worker Node1复用为Master2 Node角色（即部署Master组件）

Master2 与已部署的Master1所有操作一致。所以我们只需将Master1所有K8s文件拷贝过来，再修改下服务器IP和主机名启动即可。

7.1.1、安装Docker

scp /usr/bin/docker* root@192.168.100.32:/usr/bin
scp /usr/bin/runc root@192.168.100.32:/usr/bin
scp /usr/bin/containerd* root@192.168.100.32:/usr/bin
scp /usr/lib/systemd/system/docker.service root@192.168.100.32:/usr/lib/systemd/system
scp -r /etc/docker root@192.168.100.32:/etc
 
# 在Master2启动Docker
systemctl daemon-reload
systemctl start docker
systemctl enable docker

7.1.2、创建etcd证书目录

在Master2创建etcd证书目录：

mkdir -p /opt/etcd/ssl

7.1.3、拷贝文件（Master1操作）

拷贝Master1上所有K8s文件和etcd证书到Master2：

scp -r /opt/kubernetes root@192.168.100.32:/opt
scp -r /opt/etcd/ssl root@192.168.100.32:/opt/etcd
scp /usr/lib/systemd/system/kube* root@192.168.100.32:/usr/lib/systemd/system
scp /usr/bin/kubectl  root@192.168.100.32:/usr/bin
scp -r ~/.kube root@192.168.100.32:~

7.1.4、删除证书文件

删除kubelet证书和kubeconfig文件：

rm -f /opt/kubernetes/cfg/kubelet.kubeconfig 
rm -f /opt/kubernetes/ssl/kubelet*

7.1.5、 修改配置文件IP和主机名

修改apiserver、kubelet和kube-proxy配置文件为本地IP：

vim /opt/kubernetes/cfg/kube-apiserver.conf 
...
--bind-address=192.168.100.32 \
--advertise-address=192.168.100.32 \
...
 
vim /opt/kubernetes/cfg/kubelet.conf
--hostname-override=k8s-master2
 
vim /opt/kubernetes/cfg/kube-proxy-config.yml
hostnameOverride: k8s-master2

7.1.6、启动设置开机启动

systemctl daemon-reload
systemctl start kube-apiserver kube-controller-manager kube-scheduler kubelet kube-proxy
systemctl enable kube-apiserver kube-controller-manager kube-scheduler kubelet kube-proxy

7.1.7、查看集群状态

# 修改连接master为本机IP
vim ~/.kube/config
...
server: https://192.168.100.32:6443
 
 
kubectl get cs

7.1.8、批准kubelet证书申请

# 查看证书请求
kubectl get csr
NAME                      AGE          SIGNERNAME          REQUESTOR           CONDITION
node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU   85m   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending
# 授权请求
kubectl certificate approve node-csr-JYNknakEa_YpHz797oKaN-ZTk43nD51Zc9CJkBLcASU
 
# 查看Node
kubectl get node
NAME        STATUS   ROLES    AGE   VERSION
k8s-master1    Ready    <none>   34h   v1.20.4
k8s-master2    Ready    <none>   2m   v1.20.4
k8s-node1     Ready    <none>   33h   v1.20.4
k8s-node2     Ready    <none>   33h   v1.20.4

 7.2、部署Nginx+Keepalived高可用负载均衡器

 参考：https://www.cnblogs.com/Mr-Ding/p/17773745.html