在CentOS上搭建Kubernetes集群

如何在CentOS上安装kubernetes集群,原生安装

Posted by     "silenceper" on Friday, September 7, 2018

TOC

以下是我自己在部署k8s集群上做的一些记录,部署了一个master,一个node节点。

环境准备

我在VirtualBox中建的两个CentOS容器,并且互通:

IP 系统 角色 配置
192.168.99.101 CentOS 7.5.1804 master 1核2G
192.168.99.102 CentOS 7.5.1804 node 1核2G

安装版本:

组件 版本
Kubernetes 1.10.7
Etcd 3.1.10
Docker 17.12.1-ce

证书准备

使用CFSSL工具进行证书生成

CA证书和秘钥文件主要用来做传输加密用的,将会生成如下文件:

  • ca-key.pem
  • ca.pem
  • kubernetes-key.pem
  • kubernetes.pem
  • kube-proxy.pem
  • kube-proxy-key.pem
  • admin.pem
  • admin-key.pem

使用证书的组件如下:

  • etcd:使用 ca.pem、kubernetes-key.pem、kubernetes.pem;
  • kube-apiserver:使用 ca.pem、kubernetes-key.pem、kubernetes.pem;
  • kubelet:使用 ca.pem;
  • kube-proxy:使用 ca.pem、kube-proxy-key.pem、kube-proxy.pem;
  • kubectl:使用 ca.pem、admin-key.pem、admin.pem;
  • kube-controller-manager:使用 ca-key.pem、ca.pem

在master节点上进行操作:

wget https://pkg.cfssl.org/R1.2/cfssl_linux-amd64
chmod +x cfssl_linux-amd64
mv cfssl_linux-amd64 /usr/local/bin/cfssl

wget https://pkg.cfssl.org/R1.2/cfssljson_linux-amd64
chmod +x cfssljson_linux-amd64
mv cfssljson_linux-amd64 /usr/local/bin/cfssljson

wget https://pkg.cfssl.org/R1.2/cfssl-certinfo_linux-amd64
chmod +x cfssl-certinfo_linux-amd64
mv cfssl-certinfo_linux-amd64 /usr/local/bin/cfssl-certinfo

export PATH=/usr/local/bin:$PATH

创建ca证书

创建 ca-config.json文件:

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

创建 ca-csr.json文件:

{
  "CN": "kubernetes",
  "key": {
    "algo": "rsa",
    "size": 2048
  },
  "names": [
    {
      "C": "CN",
      "ST": "BeiJing",
      "L": "BeiJing",
      "O": "k8s",
      "OU": "System"
    }
  ],
    "ca": {
       "expiry": "87600h"
    }
}

生成ca证书和私钥

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

生成kubernetes证书

创建kubernetes-csr.json文件:

{
    "CN": "kubernetes",
    "hosts": [
      "127.0.0.1",
      "192.168.99.101",
      "192.168.99.102",
      "10.254.0.1",
      "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": "System"
        }
    ]
}

其中ip段改为自己的ip,包括etcd集群IP,k8s master集群ip,k8s服务的服务ip(一般是 kube-apiserver 指定的 service-cluster-ip-range 网段的第一个IP,如 10.254.0.1)

生成证书和私钥:

[root@localhost ssl]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes kubernetes-csr.json | cfssljson -bare kubernetes

创建admin证书

创建 admin-csr.json文件:

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

生成证书

[root@localhost ssl]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes admin-csr.json | cfssljson -bare admin

创建kube-proxy证书

创建kube-proxy-csr.json文件:

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

生成命令:

[root@localhost ssl]# cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=kubernetes  kube-proxy-csr.json | cfssljson -bare kube-proxy

分发证书

将生成的证书和秘钥文件(后缀为.pem)拷贝到所有机器的`/etc/kubernetes/ssl 目录下 > 命令略

安装kubectl文件

wget -c https://dl.k8s.io/v1.10.7/kubernetes-client-darwin-386.tar.gz
tar -xzvf kubernetes-client-linux-amd64.tar.gz
cp kubernetes/client/bin/kube* /usr/bin/
chmod a+x /usr/bin/kube*

创建 kubectl kubeconfig 文件

export KUBE_APISERVER="https://192.168.99.101:6443"
# 设置集群参数
kubectl config set-cluster kubernetes \
  --certificate-authority=/etc/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER}
# 设置客户端认证参数
kubectl config set-credentials admin \
  --client-certificate=/etc/kubernetes/ssl/admin.pem \
  --embed-certs=true \
  --client-key=/etc/kubernetes/ssl/admin-key.pem
# 设置上下文参数
kubectl config set-context kubernetes \
  --cluster=kubernetes \
  --user=admin
# 设置默认上下文
kubectl config use-context kubernetes

admin 证书中设定了 group=system:masters即(O=system:masters) 这个group与ckuster-admin ClusterRole绑定,所以具有整个集群的权限 如果需要单独指定权限,则可以自己设定user绑定ClusterRole

创建 kubeconfig 文件

创建 TLS Bootstrapping Token

$ export BOOTSTRAP_TOKEN=$(head -c 16 /dev/urandom | od -An -t x | tr -d ' ')

$ cat > token.csv <<EOF
${BOOTSTRAP_TOKEN},kubelet-bootstrap,10001,"system:kubelet-bootstrap"
EOF

$ cp token.csv /etc/kubernetes/

创建 kubelet bootstrapping kubeconfig 文件

cd /etc/kubernetes
export KUBE_APISERVER="https://192.168.99.101:6443"

# 设置集群参数
kubectl config set-cluster kubernetes \
  --certificate-authority=/etc/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=bootstrap.kubeconfig

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

# 设置上下文参数
kubectl config set-context default \
  --cluster=kubernetes \
  --user=kubelet-bootstrap \
  --kubeconfig=bootstrap.kubeconfig

# 设置默认上下文
kubectl config use-context default --kubeconfig=bootstrap.kubeconfig

创建 kube-proxy kubeconfig 文件

export KUBE_APISERVER="https://192.168.99.101:6443"
# 设置集群参数
kubectl config set-cluster kubernetes \
  --certificate-authority=/etc/kubernetes/ssl/ca.pem \
  --embed-certs=true \
  --server=${KUBE_APISERVER} \
  --kubeconfig=kube-proxy.kubeconfig
# 设置客户端认证参数
kubectl config set-credentials kube-proxy \
  --client-certificate=/etc/kubernetes/ssl/kube-proxy.pem \
  --client-key=/etc/kubernetes/ssl/kube-proxy-key.pem \
  --embed-certs=true \
  --kubeconfig=kube-proxy.kubeconfig
# 设置上下文参数
kubectl config set-context default \
  --cluster=kubernetes \
  --user=kube-proxy \
  --kubeconfig=kube-proxy.kubeconfig
# 设置默认上下文
kubectl config use-context default --kubeconfig=kube-proxy.kubeconfig

分发kubeconfig文件

将两个 kubeconfig 文件分发到所有 Node 机器的 /etc/kubernetes/ 目录

cp bootstrap.kubeconfig kube-proxy.kubeconfig /etc/kubernetes/

Etcd安装

我这里为了简单,ETCD节点只用了一个,并且安装在了master节点上,多个也是一样的,只是在--initial-cluster选择中将其他节点ip填入进去。

下载ETCD:

$ wget -c https://github.com/coreos/etcd/releases/download/v3.1.10/etcd-v3.1.10-linux-amd64.tar.gz
$ tar -zxvf etcd-v3.1.10-linux-amd64.tar.gz
$ mv etcd-v3.1.10-linux-amd64/etcd* /usr/local/bin

创建 etcd 的 systemd unit 文件

vim  /usr/lib/systemd/system/etcd.service

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/
EnvironmentFile=-/etc/etcd/etcd.conf
ExecStart=/usr/local/bin/etcd \
  --name ${ETCD_NAME} \
  --cert-file=/etc/kubernetes/ssl/kubernetes.pem \
  --key-file=/etc/kubernetes/ssl/kubernetes-key.pem \
  --peer-cert-file=/etc/kubernetes/ssl/kubernetes.pem \
  --peer-key-file=/etc/kubernetes/ssl/kubernetes-key.pem \
  --trusted-ca-file=/etc/kubernetes/ssl/ca.pem \
  --peer-trusted-ca-file=/etc/kubernetes/ssl/ca.pem \
  --initial-advertise-peer-urls ${ETCD_INITIAL_ADVERTISE_PEER_URLS} \
  --listen-peer-urls ${ETCD_LISTEN_PEER_URLS} \
  --listen-client-urls ${ETCD_LISTEN_CLIENT_URLS},http://127.0.0.1:2379 \
  --advertise-client-urls ${ETCD_ADVERTISE_CLIENT_URLS} \
  --initial-cluster-token ${ETCD_INITIAL_CLUSTER_TOKEN} \
  --initial-cluster infra1=https://192.168.99.101:2380 \
  --initial-cluster-state new \
  --data-dir=${ETCD_DATA_DIR}
Restart=on-failure
RestartSec=5
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

创建/etc/etcd/etcd.conf文件:

# [member]
ETCD_NAME=infra1
ETCD_DATA_DIR="/var/lib/etcd"
ETCD_LISTEN_PEER_URLS="https://192.168.99.101:2380"
ETCD_LISTEN_CLIENT_URLS="https://192.168.99.101:2379"

#[cluster]
ETCD_INITIAL_ADVERTISE_PEER_URLS="https://192.168.99.101:2380"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_ADVERTISE_CLIENT_URLS="https://192.168.99.101:2379"

启动服务:

mv etcd.service /usr/lib/systemd/system/
systemctl daemon-reload
systemctl enable etcd
systemctl start etcd
systemctl status etcd

验证服务:

etcdctl   --ca-file=/etc/kubernetes/ssl/ca.pem   --cert-file=/etc/kubernetes/ssl/kubernetes.pem   --key-file=/etc/kubernetes/ssl/kubernetes-key.pem   cluster-health
2018-09-07 15:41:30.782777 I | warning: ignoring ServerName for user-provided CA for backwards compatibility is deprecated
2018-09-07 15:41:30.783295 I | warning: ignoring ServerName for user-provided CA for backwards compatibility is deprecated
member 171ef35542ebf92b is healthy: got healthy result from https://192.168.99.101:2379
cluster is healthy

cluster is healthy表示成功。

Master节点部署

master节点上主要是三个组件:

  • kube-apiserver
  • kube-scheduler
  • kube-controller-manager

同事只能又一个kube-scheduler,kube-controller-manager进程处于工作状态,如果运行多个,则需要通过选举产生一个leader。

下载server包:

wget -c https://dl.k8s.io/v1.10.7/kubernetes-server-linux-amd64.tar.gz
tar -xzvf kubernetes-server-linux-amd64.tar.gz
cd kubernetes
tar -xzvf  kubernetes-src.tar.gz

将二进制文件拷贝到指定路径

cp -r server/bin/{kube-apiserver,kube-controller-manager,kube-scheduler} /usr/local/bin/

同时将 server/bin/目录下的kube-proxy,kubelet 三个文件复制到node节点的 /usr/local/bin/ 目录

配置和启动 kube-apiserver

创建 /etc/kubernetes/config文件:

###
# kubernetes system config
#
# The following values are used to configure various aspects of all
# kubernetes services, including
#
#   kube-apiserver.service
#   kube-controller-manager.service
#   kube-scheduler.service
#   kubelet.service
#   kube-proxy.service
# logging to stderr means we get it in the systemd journal
KUBE_LOGTOSTDERR="--logtostderr=true"

# journal message level, 0 is debug
KUBE_LOG_LEVEL="--v=0"

# Should this cluster be allowed to run privileged docker containers
KUBE_ALLOW_PRIV="--allow-privileged=true"

# How the controller-manager, scheduler, and proxy find the apiserver

KUBE_MASTER="--master=http://192.168.99.101:8080"

创建service文件/usr/lib/systemd/system/kube-apiserver.service

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

[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/apiserver
ExecStart=/usr/local/bin/kube-apiserver \
        $KUBE_LOGTOSTDERR \
        $KUBE_LOG_LEVEL \
        $KUBE_ETCD_SERVERS \
        $KUBE_API_ADDRESS \
        $KUBE_API_PORT \
        $KUBELET_PORT \
        $KUBE_ALLOW_PRIV \
        $KUBE_SERVICE_ADDRESSES \
        $KUBE_ADMISSION_CONTROL \
        $KUBE_API_ARGS
Restart=on-failure
Type=notify
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

apiserver的配置文件 /etc/kubernetes/apiserver:

###
## kubernetes system config
##
## The following values are used to configure the kube-apiserver
##
#
## The address on the local server to listen to.
KUBE_API_ADDRESS="--advertise-address=192.168.99.101 --bind-address=192.168.99.101 --insecure-bind-address=192.168.99.101"
#
## The port on the local server to listen on.
#KUBE_API_PORT="--port=8080"
#
## Port minions listen on
#KUBELET_PORT="--kubelet-port=10250"
#
## Comma separated list of nodes in the etcd cluster
KUBE_ETCD_SERVERS="--etcd-servers=https://192.168.99.101:2379"
#
## Address range to use for services
KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"
#
## default admission control policies
KUBE_ADMISSION_CONTROL="--admission-control=ServiceAccount,NamespaceLifecycle,NamespaceExists,LimitRanger,ResourceQuota"
#
## Add your own!
KUBE_API_ARGS="--authorization-mode=Node,RBAC --runtime-config=rbac.authorization.k8s.io/v1beta1 --kubelet-https=true --enable-bootstrap-token-auth --token-auth-file=/etc/kubernetes/token.csv --service-node-port-range=30000-32767 --tls-cert-file=/etc/kubernetes/ssl/kubernetes.pem --tls-private-key-file=/etc/kubernetes/ssl/kubernetes-key.pem --client-ca-file=/etc/kubernetes/ssl/ca.pem --service-account-key-file=/etc/kubernetes/ssl/ca-key.pem --etcd-cafile=/etc/kubernetes/ssl/ca.pem --etcd-certfile=/etc/kubernetes/ssl/kubernetes.pem --etcd-keyfile=/etc/kubernetes/ssl/kubernetes-key.pem --enable-swagger-ui=true --apiserver-count=3 --audit-log-maxage=30 --audit-log-maxbackup=3 --audit-log-maxsize=100 --audit-log-path=/var/lib/audit.log --event-ttl=1h"

启动kube-apiserver:

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

配置和启动 kube-controller-manager

创建 /usr/lib/systemd/system/kube-controller-manager.service文件:

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

[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/controller-manager
ExecStart=/usr/local/bin/kube-controller-manager \
        $KUBE_LOGTOSTDERR \
        $KUBE_LOG_LEVEL \
        $KUBE_MASTER \
        $KUBE_CONTROLLER_MANAGER_ARGS
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

配置文件:/etc/kubernetes/controller-manager

###
# The following values are used to configure the kubernetes controller-manager

# defaults from config and apiserver should be adequate

# Add your own!
KUBE_CONTROLLER_MANAGER_ARGS="--address=127.0.0.1 --service-cluster-ip-range=10.254.0.0/16 --cluster-name=kubernetes --cluster-signing-cert-file=/etc/kubernetes/ssl/ca.pem --cluster-signing-key-file=/etc/kubernetes/ssl/ca-key.pem  --service-account-private-key-file=/etc/kubernetes/ssl/ca-key.pem --root-ca-file=/etc/kubernetes/ssl/ca.pem --leader-elect=true"

启动 kube-controller-manager:

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

配置和启动 kube-scheduler

创建/usr/lib/systemd/system/kube-scheduler.service文件:

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

[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/scheduler
ExecStart=/usr/local/bin/kube-scheduler \
            $KUBE_LOGTOSTDERR \
            $KUBE_LOG_LEVEL \
            $KUBE_MASTER \
            $KUBE_SCHEDULER_ARGS
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

/etc/kubernetes/scheduler文件:

###
# kubernetes scheduler config

# default config should be adequate

# Add your own!
KUBE_SCHEDULER_ARGS="--leader-elect=true --address=127.0.0.1"

启动 kube-scheduler:

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

验证master节点

[root@localhost ~]# kubectl get componentstatuses
NAME                 STATUS    MESSAGE              ERROR
scheduler            Healthy   ok
controller-manager   Healthy   ok
etcd-0               Healthy   {"health": "true"}

安装Flannel网络插件

Flannel网络插件只需要安装在node节点上就好了,他主要作用是将不同node上的pod网络联通,所以我们在102这台机器上操作:

使用yum直接安装:

yum install -y flannel

创建 /usr/lib/systemd/system/flanneld.service文件:

[Unit]
Description=Flanneld overlay address etcd agent
After=network.target
After=network-online.target
Wants=network-online.target
After=etcd.service
Before=docker.service

[Service]
Type=notify
EnvironmentFile=/etc/sysconfig/flanneld
EnvironmentFile=-/etc/sysconfig/docker-network
ExecStart=/usr/bin/flanneld-start \
  -etcd-endpoints=${FLANNEL_ETCD_ENDPOINTS} \
  -etcd-prefix=${FLANNEL_ETCD_PREFIX} \
  $FLANNEL_OPTIONS
ExecStartPost=/usr/libexec/flannel/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /run/flannel/docker
Restart=on-failure

[Install]
WantedBy=multi-user.target
RequiredBy=docker.service

/etc/sysconfig/flanneld文件:

# Flanneld configuration options

# etcd url location.  Point this to the server where etcd runs
FLANNEL_ETCD_ENDPOINTS="https://192.168.99.101:2379"

# etcd config key.  This is the configuration key that flannel queries
# For address range assignment
FLANNEL_ETCD_PREFIX="/kube-centos/network"

# Any additional options that you want to pass
FLANNEL_OPTIONS="-etcd-cafile=/etc/kubernetes/ssl/ca.pem -etcd-certfile=/etc/kubernetes/ssl/kubernetes.pem -etcd-keyfile=/etc/kubernetes/ssl/kubernetes-key.pem"

在etcd中创建网络配置,在master节点上操作就好了,省得指定endpoints:

$ etcdctl   --ca-file=/etc/kubernetes/ssl/ca.pem   --cert-file=/etc/kubernetes/ssl/kubernetes.pem   --key-file=/etc/kubernetes/ssl/kubernetes-key.pem  mkdir /kube-centos/network

$ etcdctl   --ca-file=/etc/kubernetes/ssl/ca.pem   --cert-file=/etc/kubernetes/ssl/kubernetes.pem   --key-file=/etc/kubernetes/ssl/kubernetes-key.pem  mk /kube-centos/network/config '{"Network":"172.30.0.0/16","SubnetLen":24,"Backend":{"Type":"vxlan"}}'

启动flannel

systemctl daemon-reload
systemctl enable flanneld
systemctl start flanneld
systemctl status flanneld

Docker安装

下载并安装:

wget -c https://download.docker.com/linux/centos/7/x86_64/stable/Packages/docker-ce-17.12.1.ce-1.el7.centos.x86_64.rpm
yum install docker-ce-17.12.1.ce-1.el7.centos.x86_64.rpm 

/usr/lib/systemd/system/docker.service文件中增加一个环境变量:

EnvironmentFile=-/run/flannel/docker

并且启动命令为,主要是增加了一个$DOCKER_NETWORK_OPTIONS参数是flannel传入的用来修改docker0网桥IP

ExecStart=/usr/bin/dockerd $DOCKER_NETWORK_OPTIONS --log-driver=json-file --log-opt max-size=50m --log-opt max-file=5

启动:

systemctl daemon-reload
systemctl enable docker
systemctl start docker
systemctl status docker

Node节点部署

kube-proxykubelet 文件在kubernetes-server-linux-amd64.tar.gz,复制到/usr/local/bin目录

安装配置kubelet

前提:关闭swap,否则无法启动 使用:swapoff -a或者注释fstab中swap配置

TIPS: 现在master节点上,赋予kubelet-bootstrap用户,system:node-bootstrapper cluster 角色,否则kubelet没有权限创建认证请求。

cd /etc/kubernetes
kubectl create clusterrolebinding kubelet-bootstrap \
  --clusterrole=system:node-bootstrapper \
  --user=kubelet-bootstrap

文件/usr/lib/systemd/system/kubelet.service

[Unit]
Description=Kubernetes Kubelet Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=docker.service
Requires=docker.service

[Service]
WorkingDirectory=/var/lib/kubelet
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/kubelet
ExecStart=/usr/local/bin/kubelet \
            $KUBE_LOGTOSTDERR \
            $KUBE_LOG_LEVEL \
            $KUBELET_ADDRESS \
            $KUBELET_HOSTNAME \
            $KUBE_ALLOW_PRIV \
            $KUBELET_ARGS
Restart=on-failure

[Install]
WantedBy=multi-user.target

同时配置/etc/kubernetes/kubelet文件:

###
## kubernetes kubelet (minion) config
#
## The address for the info server to serve on (set to 0.0.0.0 or "" for all interfaces)
KUBELET_ADDRESS="--address=192.168.99.102"
#
## You may leave this blank to use the actual hostname
KUBELET_HOSTNAME="--hostname-override=192.168.99.102"

KUBELET_ARGS="--bootstrap-kubeconfig=/etc/kubernetes/bootstrap.kubeconfig --kubeconfig=/etc/kubernetes/kubelet.kubeconfig --cert-dir=/etc/kubernetes/ssl --cluster-domain=cluster.local --hairpin-mode promiscuous-bridge --serialize-image-pulls=false"

启动:

systemctl daemon-reload
systemctl enable kubelet
systemctl start kubelet
systemctl status kubelet

通过kublet的TLS证书请求

[root@localhost kubernetes]# kubectl get csr
NAME                                                   AGE       REQUESTOR           CONDITION
node-csr-vtB-rALjRudPIp4IvIHwOTOggoJC-213GpvDoYVqQlA   18s       kubelet-bootstrap   Pending

通过 CSR 请求:

[root@localhost kubernetes]# kubectl certificate approve node-csr-vtB-rALjRudPIp4IvIHwOTOggoJC-213GpvDoYVqQlA
certificatesigningrequest.certificates.k8s.io "node-csr-vtB-rALjRudPIp4IvIHwOTOggoJC-213GpvDoYVqQlA" approved

配置 kube-proxy

安装conntrack:

yum install -y conntrack-tools

文件/usr/lib/systemd/system/kube-proxy.service

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

[Service]
EnvironmentFile=-/etc/kubernetes/config
EnvironmentFile=-/etc/kubernetes/proxy
ExecStart=/usr/bin/kube-proxy \
        $KUBE_LOGTOSTDERR \
        $KUBE_LOG_LEVEL \
        $KUBE_MASTER \
        $KUBE_PROXY_ARGS
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

/etc/kubernetes/proxy文件:

###
# kubernetes proxy config

# default config should be adequate

# Add your own!
KUBE_PROXY_ARGS="--bind-address=192.168.99.102 --hostname-override=192.168.99.102 --kubeconfig=/etc/kubernetes/kube-proxy.kubeconfig --cluster-cidr=10.254.0.0/16"

启动kube-proxy:

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

支持集群的基本功能已经有了,可以建一个部署一个nginx应用试一下看一下。

安装kubedns插件

kubedns 为我们提供了服务发现的功能。

yaml文件通过这里下载:

https://github.com/silenceper/k8s-install/tree/master/kube-dns

在master上执行:

kubectl create -f .

至此,k8s就搭建完成了!

参考资料:

https://jimmysong.io/kubernetes-handbook/practice/install-kubernetes-on-centos.html


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