kubernetes install

前置知识点

生产环境部署k8s 集群有两种模式

  • kubeadm: Kubeadm是一个K8s部署工具,提供kubeadm init和kubeadm join,用于快速部署Kubernetes集群
  • 二进制包: 从github下载发行版的二进制包,手动部署每个组件,组成Kubernetes集群。Kubeadm降低部署门槛,但屏蔽了很多细节,遇到问题很难排查。如果想更容易可控,推荐使用二进制包部署Kubernetes集群,虽然手动部署麻烦点,期间可以学习很多工作原理,也利于后期维护

k8s 各种组件


环境

安装要求


机器(aliyun)

  • 172.26.3.200(centos 7.8 2c4g) k8s-master 11
  • 172.26.3.201(centos 7.8 2c4g) k8s-node1 227
  • 172.26.3.202(centos 7.8 2c4g) k8s-node2 185

环境准备

关闭防火墙

systemctl stop firewalld
systemctl disable firewalld

关闭selinux

sed -i 's/enforcing/disabled/' /etc/selinux/config  # 永久
setenforce 0  # 临时

关闭swap

swapoff -a  # 临时
sed -ri 's/.*swap.*/#&/' /etc/fstab    # 永久

修改主机名

hostnamectl set-hostname k8s-master
hostnamectl set-hostname k8s-node1
hostnamectl set-hostname k8s-node2

在master添加hosts

cat >> /etc/hosts << EOF
172.26.3.200 k8s-master
172.26.3.201 k8s-node01
172.26.3.200 k8s-node02
EOF

将桥接的IPv4流量传递到iptables的链,并调整内核参数

cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward=1
net.ipv4.tcp_tw_recycle=0
vm.swappiness=0
vm.overcommit_memory=1
vm.panic_on_oom=0
fs.inotify.max_user_instances=8192
fs.inotify.max_user_watches=1048576
fs.file-max=52706963
fs.nr_open=52706963
net.ipv6.conf.all.disable_ipv6=1
net.netfilter.nf_conntrack_max=2310720
EOF
sysctl --system  # 生效

时间同步

yum install ntpdate -y
ntpdate ntp.aliyun.com

更新内核

rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-4.el7.elrepo.noarch.rpm
#安装内核
yum --enablerepo=elrepo-kernel install -y kernel-lt
查看当前的所有内核版本
cat /boot/grub2/grub.cfg | grep menuentry
查看当前启动内核版本
grub2-editenv list
修改启动内核版本,设置开机从新内核启动
grub2-set-default 'CentOS Linux (5.4.108-1.el7.elrepo.x86_64) 7 (Core)'
#注意:设置完内核后,需要重启服务器才会生效。
#查询内核
uname -r

部署 Etcd 集群

Etcd节点分配

  • 172.26.3.200 etcd1
  • 172.26.3.201 etcd2
  • 172.26.3.202 etcd3

准备cfssl证书生成工具

cfssl是一个开源的证书管理工具,使用json文件生成证书,相比openssl更方便使用。 找任意一台服务器操作,这里用Master节点

wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
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

生成Etcd证书

创建工作目录

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

自签CA

  • ca-config.json
cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "www": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF
  • ca-csr.json
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 -
ls *pem
ca-key.pem  ca.pem

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": [
    "172.26.3.200",
    "172.26.3.201",
    "172.26.3.202"
    ],
    "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

ls server*pem
server-key.pem  server.pem

从Github下载二进制文件

下载地址: https://github.com/etcd-io/etcd/releases/download/v3.4.15/etcd-v3.4.15-linux-amd64.tar.gz

部署Etcd集群

以下在节点1上操作,为简化操作,待会将节点1生成的所有文件拷贝到节点2和节点3

创建工作目录并解压二进制包

mkdir /opt/etcd/{bin,cfg,ssl} -p
tar zxvf etcd-v3.4.15-linux-amd64.tar.gz
mv etcd-v3.4.15-linux-amd64/{etcd,etcdctl} /opt/etcd/bin/

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://172.26.3.200:2380"
ETCD_LISTEN_CLIENT_URLS="https://172.26.3.200:2379"
#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://172.26.3.200:2380"
ETCD_ADVERTISE_CLIENT_URLS="https://172.26.3.200:2379"
ETCD_INITIAL_CLUSTER="etcd-1=https://172.26.3.200:2380,etcd-2=https://172.26.3.201:2380,etcd-3=https://172.26.3.202:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"
EOF

说明:

  • 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_PEER_URLS: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_INITIAL_CLUSTER_TOKEN:集群Token
  • ETCD_INITIAL_CLUSTER_STATE:加入集群的当前状态,new是新集群,existing表示加入已有集群

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

拷贝刚才生成的证书

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

启动并设置开机启动

systemctl daemon-reload
systemctl start etcd
systemctl enable etcd

将上面节点1所有生成的文件拷贝到节点2和节点3

scp -r /opt/etcd/ root@172.26.3.201:/opt/
scp /usr/lib/systemd/system/etcd.service root@172.26.3.201:/usr/lib/systemd/system/
scp -r /opt/etcd/ root@172.26.3.202:/opt/
scp /usr/lib/systemd/system/etcd.service root@172.26.3.202:/usr/lib/systemd/system/

然后在节点2和节点3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-1"   # 修改此处,节点2改为etcd-2,节点3改为etcd-3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="https://172.26.3.200:2380"   # 修改此处为当前服务器IP
ETCD_LISTEN_CLIENT_URLS="https://172.26.3.200:2379" # 修改此处为当前服务器IP

#[Clustering]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://172.26.3.200:2380" # 修改此处为当前服务器IP
ETCD_ADVERTISE_CLIENT_URLS="https://172.26.3.200:2379" # 修改此处为当前服务器IP
ETCD_INITIAL_CLUSTER="etcd-1=https://172.26.3.200:2380,etcd-2=https://172.26.3.201:2380,etcd-3=https://172.26.3.202:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_INITIAL_CLUSTER_STATE="new"

注:节点2,节点3按照上面操作修改完配置文件后,请执行上面第5步,启动Etcd并设置开机启动

查看集群状态,如果和下面显示一样,说明集群部署成功

[root@k8s-master ~]# /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://172.26.3.200:2379,https://172.26.3.201:2379,https://172.26.3.202:2379" endpoint health
https://172.26.3.200:2379 is healthy: successfully committed proposal: took = 9.304973ms
https://172.26.3.202:2379 is healthy: successfully committed proposal: took = 10.072233ms
https://172.26.3.201:2379 is healthy: successfully committed proposal: took = 13.895536ms

安装 docker

以下操作在所有节点操作

yum 安装 docker(和下面的二进制安装 docker 二选一即可)

sudo yum remove docker docker-client docker-client-latest docker-common docker-latest docker-latest-logrotate docker-logrotate docker-engine
sudo yum install -y yum-utils
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
sudo yum-config-manager --enable docker-ce-nightly
sudo yum install docker-ce docker-ce-cli containerd.io

二进制安装 docker

下载二进制 docker 包, 然后解压

wget https://download.docker.com/linux/static/stable/x86_64/docker-19.03.9.tgz
tar zxvf docker-19.03.9.tgz
mv docker/* /usr/bin

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

创建配置文件

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

注:registry-mirrors 阿里云镜像加速器,根据自己的需要换成自己的

启动docker并设置开机启动

systemctl daemon-reload
systemctl start docker
systemctl enable docker

部署Master Node

生成kube-apiserver证书

进入到相应工作目录

cd ~/TLS/k8s #此目录上面已经创建了

自签证书颁发机构(CA)

  • ca-config.json
cat > ca-config.json << EOF
{
  "signing": {
    "default": {
      "expiry": "87600h"
    },
    "profiles": {
      "kubernetes": {
         "expiry": "87600h",
         "usages": [
            "signing",
            "key encipherment",
            "server auth",
            "client auth"
        ]
      }
    }
  }
}
EOF
  • ca-csr.json
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 -

ls *pem
ca-key.pem  ca.pem

使用自签CA签发kube-apiserver HTTPS证书

  1. 创建证书申请文件

    cat > server-csr.json << EOF
    {
        "CN": "kubernetes",
        "hosts": [
          "10.0.0.1",
          "127.0.0.1",
          "172.26.3.200",
          "172.26.3.201",
          "172.26.3.202",
          "172.26.3.203",
          "172.26.3.204",
          "172.26.3.205",
          "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

  2. 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 server
    
    ls server*pem
    server-key.pem  server.pem
    

下载二进制包

下载页面:https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.19.md#v1199 有很多包,找对应平台的 server包即可

wget https://dl.k8s.io/v1.19.9/kubernetes-server-linux-amd64.tar.gz

解压二进制包

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/

部署kube-apiserver

创建配置文件

cat > /opt/kubernetes/cfg/kube-apiserver.conf << EOF
KUBE_APISERVER_OPTS="--logtostderr=false \\
--v=2 \\
--log-dir=/opt/kubernetes/logs \\
--etcd-servers=https://172.26.3.200:2379,https://172.26.3.201:2379,https://172.26.3.202:2379 \\
--bind-address=172.26.3.200 \\
--secure-port=6443 \\
--advertise-address=172.26.3.200 \\
--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 \\
--etcd-cafile=/opt/etcd/ssl/ca.pem \\
--etcd-certfile=/opt/etcd/ssl/server.pem \\
--etcd-keyfile=/opt/etcd/ssl/server-key.pem \\
--audit-log-maxage=30 \\
--audit-log-maxbackup=3 \\
--audit-log-maxsize=100 \\
--audit-log-path=/opt/kubernetes/logs/k8s-audit.log"
EOF

注:

  • –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
  • –etcd-xxxfile:连接Etcd集群证书
  • –audit-log-xxx:审计日志
  1. 拷贝刚才生成的证书
cp ~/TLS/k8s/ca*pem ~/TLS/k8s/server*pem /opt/kubernetes/ssl/

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 a. 创建上述配置文件中token文件 shell cat > /opt/kubernetes/cfg/token.csv << EOF 3250cbe3576f5ab28ff4a46d9ecd129b,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 shell head -c 16 /dev/urandom | od -An -t x | tr -d ' '

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

启动并设置开机启动

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

授权kubelet-bootstrap用户允许请求证书

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

部署kube-controller-manager

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 \\
--master=127.0.0.1:8080 \\
--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 \\
--experimental-cluster-signing-duration=87600h0m0s"
EOF
  • –master:通过本地非安全本地端口8080连接apiserver。
  • –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

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

启动并设置开机启动

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

部署kube-scheduler

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 \
--master=127.0.0.1:8080 \
--bind-address=127.0.0.1"
EOF
  • –master:通过本地非安全本地端口8080连接apiserver。
  • –leader-elect:当该组件启动多个时,自动选举(HA)

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

启动并设置开机启动

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

查看集群状态

如上输出说明Master节点组件运行正常

[root@k8s-master ~]# kubectl get cs
Warning: v1 ComponentStatus is deprecated in v1.19+
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok
controller-manager   Healthy   ok
etcd-1               Healthy   {"health":"true"}
etcd-0               Healthy   {"health":"true"}
etcd-2               Healthy   {"health":"true"}

部署Worker Node

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 kubernetes/server/bin
cp kubelet kube-proxy /opt/kubernetes/bin   # 本地拷贝

部署kubelet

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-master \\
--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

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

生成bootstrap.kubeconfig文件

KUBE_APISERVER="https://172.26.3.200:6443" # apiserver IP:PORT
TOKEN="3250cbe3576f5ab28ff4a46d9ecd129b" # 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=${KUBE_APISERVER} \
  --kubeconfig=bootstrap.kubeconfig
kubectl config set-credentials "kubelet-bootstrap" \
  --token=${TOKEN} \
  --kubeconfig=bootstrap.kubeconfig
kubectl config set-context default \
  --cluster=kubernetes \
  --user="kubelet-bootstrap" \
  --kubeconfig=bootstrap.kubeconfig
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig

拷贝到配置文件路径

cp bootstrap.kubeconfig /opt/kubernetes/cfg

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

启动并设置开机启动

systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet

批准kubelet证书申请并加入集群

# 查看kubelet证书请求
kubectl get csr
NAME                                                   AGE    SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-NsZ_wMt-h0zEQBpFhF9mAZ_Qme0GA-js43LpWNqwzrU   6m3s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

# 批准申请
kubectl certificate approve node-csr-NsZ_wMt-h0zEQBpFhF9mAZ_Qme0GA-js43LpWNqwzrU

# 查看节点
kubectl get node
NAME         STATUS     ROLES    AGE   VERSION
k8s-master   NotReady   <none>   7s    v1.18.3

注:由于网络插件还没有部署,节点会没有准备就绪 NotReady

部署kube-proxy

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

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-master
clusterCIDR: 10.0.0.0/24
EOF

生成kube-proxy.kubeconfig文件

  1. 切换工作目录
cd TLS/k8s
  1. 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
  1. 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

ls kube-proxy*pem
kube-proxy-key.pem  kube-proxy.pem
  1. 生成kubeconfig文件
KUBE_APISERVER="https://172.26.3.200:6443"

kubectl config set-cluster kubernetes \
  --certificate-authority=/opt/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=kube-proxy.kubeconfig
kubectl config set-credentials kube-proxy \
  --client-certificate=./kube-proxy.pem \
  --client-key=./kube-proxy-key.pem \
  --embed-certs=true \
  --kubeconfig=kube-proxy.kubeconfig
kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-proxy \
  --kubeconfig=kube-proxy.kubeconfig
kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig
  1. 拷贝到配置文件指定路径
cp kube-proxy.kubeconfig /opt/kubernetes/cfg/

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
  1. 启动并设置开机启动
systemctl daemon-reload
systemctl start kube-proxy
systemctl enable kube-proxy

部署CNI网络

先准备好 CNI二进制包

wget https://github.com/containernetworking/plugins/releases/download/v0.8.6/cni-plugins-linux-amd64-v0.8.6.tgz

解压二进制包并移动到默认工作目录

mkdir /opt/cni/bin
tar zxvf cni-plugins-linux-amd64-v0.8.6.tgz -C /opt/cni/bin

部署CNI网络

wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
sed -i -r "s#quay.io/coreos/flannel:.*-rc2#lizhenliang/flannel:v0.12.0-amd64#g" kube-flannel.yml

注:默认镜像地址无法访问,修改为docker hub镜像仓库 部署好网络插件,如下显示正常。

kubectl apply -f kube-flannel.yml

kubectl get pods -n kube-system
NAME                    READY   STATUS    RESTARTS   AGE
kube-flannel-ds-f58vw   1/1     Running   0          44s

kubectl get node
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    <none>   96m   v1.19.9

授权apiserver访问kubelet

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

新增加Worker Node

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 172.26.3.201/202

# k8s-node1
scp -r /opt/kubernetes root@172.26.3.201:/opt/
scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@172.26.3.201:/usr/lib/systemd/system
scp -r /opt/cni/ root@172.26.3.201:/opt/
scp /opt/kubernetes/ssl/ca.pem root@172.26.3.201:/opt/kubernetes/ssl
# k8s-node2
scp -r /opt/kubernetes root@172.26.3.202:/opt/
scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@172.26.3.202:/usr/lib/systemd/system
scp -r /opt/cni/ root@172.26.3.202:/opt/
scp /opt/kubernetes/ssl/ca.pem root@172.26.3.202:/opt/kubernetes/ssl

删除kubelet证书和kubeconfig文件

rm /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,必须删除重新生成

修改主机名

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

启动并设置开机启动

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

在Master上批准新Node kubelet证书申请

kubectl get csr
NAME                                                   AGE   SIGNERNAME                                    REQUESTOR           CONDITION
node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro   89s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

kubectl certificate approve node-csr-4zTjsaVSrhuyhIGqsefxzVoZDCNKei-aE2jyTP81Uro

查看Node状态

kubectl get node
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    <none>   15h   v1.19.9
k8s-node1    Ready    <none>   13h   v1.19.9
k8s-node2    Ready    <none>   13h   v1.19.9

Node2(172.26.3.202 )节点同上。记得修改主机名

部署Dashboard和CoreDNS

部署Dashboard

下载 yaml 文件

wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.2.0/aio/deploy/recommended.yaml

默认Dashboard只能集群内部访问,修改Service为NodePort类型,暴露到外部

vi recommended.yaml
kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30001
  type: NodePort
  selector:
    k8s-app: kubernetes-dashboard

部署 dashboard

kubectl apply -f recommended.yaml

查看dashboard信息

kubectl get pods,svc -n kubernetes-dashboard
NAME                                             READY   STATUS              RESTARTS   AGE
pod/dashboard-metrics-scraper-694557449d-z8gfb   1/1     Running             0          2m18s
pod/kubernetes-dashboard-9774cc786-q2gsx         1/1     Running		     0          2m19s

NAME                                TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)         AGE
service/dashboard-metrics-scraper   ClusterIP   10.0.0.141   <none>        8000/TCP        2m19s
service/kubernetes-dashboard        NodePort    10.0.0.239   <none>        443:30001/TCP   2m19s

访问地址:https://NodeIP:30001 (chrome 不支持自签证书,需要使用 firefox 访问)

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

eyJhbGciOiJSUzI1NiIsImtpZCI6IkNERFlwZnp1QmI5enhzVEozMnMybWZ4OEtMU1FLUWVjd1FJQ0ZlOURQbUUifQ.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.JqpIqrvTRcCBdd4pKTqUyaj91Y7jvWm8nX8X5ozdz-kKfyaQzb_MAq029fwLLK2i19hPqK5sGG9_vPsuHqEcP07dwtmqAsSNeFS0wXeFob-d9rwmtR1_6V5ulxgTzAJoG4qja23iehqpCrNJs8sa_ffNSR6huzFTG2ZDcHr1RN1zBfXXzsEmlu3eTlXj1cqg4kG-CRdOHGb7UDfUopLTOoe1_l0IE6J30gdQbaXthkGlw2paNwnLnDH_6i69B1ftvunh_Ev447UZ5mTkR9ZX4-ryZy7PwEMxbMFJaGqCUmp9DYRNesHlXXCbxq47sXoK46MkgTVv8RWd8xA3YOcZEQ

部署CoreDNS

准备 coredns.yaml

wget https://raw.githubusercontent.com/coredns/deployment/master/kubernetes/coredns.yaml.sed
wget https://raw.githubusercontent.com/coredns/deployment/master/kubernetes/deploy.sh
chmod +x deploy.sh
./deploy.sh -i 10.96.0.10 > coredns.yaml	#deploy.sh 需要 jq 工具,如果提示没有请安装`yum -y install jq`

部署 coredns

kubectl apply -f coredns.yaml# 查看kubectl get pods --namespace kube-system
kubectl get svc --namespace kube-system

DNS解析测试

kubectl run -it --rm dns-test --image=busybox:1.28.4 sh