Kubernetes(k8s)简介

Kubernetes是容器集群管理系统,是一个开源的平台,可以实现容器集群的自动化部署、自动扩缩容、维护等功能。

安装环境说明

系统:debian-10.7
平台:amd64

参考文献

Kubernetes中文社区 | 中文文档
etcd 集群部署
k8s简介以及linux环境下的详细安装步骤
二进制方式搭建一个完整K8s集群

关键术语说明

Etcd:Etcd 是 CoreOS 基于 Raft 开发的分布式 key-value 存储,可用于服务发现、共享配置以及一致性保障(如数据库选主、分布式锁等)。
kube-apiserver:Kubernetes API 服务器验证并配置 API 对象的数据, 这些对象包括 pods、services、replicationcontrollers 等。 API 服务器为 REST 操作提供服务,并为集群的共享状态提供前端, 所有其他组件都通过该前端进行交互。
kube-controller-manager:Controller Manager作为集群内部的管理控制中心,负责集群内的Node、Pod副本、服务端点(Endpoint)、命名空间(Namespace)、服务账号(ServiceAccount)、资源定额(ResourceQuota)的管理,当某个Node意外宕机时,Controller Manager会及时发现并执行自动化修复流程,确保集群始终处于预期的工作状态。
kubelet:kubelet 是在每个 Node 节点上运行的主要 “节点代理”。它可以使用以下之一向 apiserver 注册: 主机名(hostname);覆盖主机名的参数;某云驱动的特定逻辑。
kube-proxy:Kubernetes 网络代理在每个节点上运行。网络代理反映了每个节点上 Kubernetes API 中定义的服务,并且可以执行简单的 TCP、UDP 和 SCTP 流转发,或者在一组后端进行循环 TCP、UDP 和 SCTP 转发。当前可通过 Docker-links-compatible 环境变量找到服务集群 IP 和端口,这些环境变量指定了服务代理打开的端口。有一个可选的插件,可以为这些集群 IP 提供集群 DNS。用户必须使用 apiserver API 创建服务才能配置代理。

一键安装工具

常见的一键安装工具有以下几种
kind:使用kind来快速部署k8s环境
kubeadm:官方文档
Rancher官方文档

环境准备

角色操作系统HostNameIP地址组件
k8s-master1Debian GNU/Linux 10.7 (buster)master-01192.168.24.21kube-scheduler、kube-controller-manager、kube-apiserver、etcd
k8s-master2Debian GNU/Linux 10.7 (buster)master-02192.168.24.22kube-scheduler、kube-controller-manager、kube-apiserver、etcd
k8s-master3Debian GNU/Linux 10.7 (buster)master-03192.168.24.23kube-scheduler、kube-controller-manager、kube-apiserver、etcd
node-04Debian GNU/Linux 10.7 (buster)node-04192.168.24.24kube-proxy、kubelet、kube-scheduler、kube-controller-manager、kube-apiserver、docker
node-05Debian GNU/Linux 10.7 (buster)node-05192.168.24.25kube-proxy、kubelet、kube-scheduler、kube-controller-manager、kube-apiserver、docker
node-04Debian GNU/Linux 10.7 (buster)node-06192.168.24.26kube-proxy、kubelet、kube-scheduler、kube-controller-manager、kube-apiserver、docker

常用命令准备

  1. 修改主机名称
hostnamectl set-hostname node-05

软件版本说明

软件名称版本
Etcd3.4.14
Docker20.10.2
Kubernetes1.18.15
cni0.9.0

依赖应用安装

Etcd集群安装

etcd 集群部署

docker安装部署

使用二进制方式安装docker

创建安装目录结构

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

生成证书

  1. 生成kube-apiserver证书
cd /opt/kubernetes/ssl
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
  1. 使用自签CA签发kube-apiserver HTTPS证书
cd /opt/kubernetes/ssl
cat > server-csr.json << EOF
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "127.0.0.1",
      "192.168.24.21",
      "192.168.24.22",
      "192.168.24.23",
      "192.168.24.24",
      "192.168.24.25",
      "192.168.24.26",
      "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 server
  1. 生成kube-controller-manager证书与私钥(说明:本步骤无需操作)
    (1) kube-controller-mamager连接 apiserver 需要使用的证书,同时本身 10257 端口也会使用此证书
    (2) kube-controller-mamager与kubei-apiserver通信采用双向TLS认证
cd /opt/kubernetes/ssl
cat > kube-controller-manager-csr.json << EOF
{
    "CN": "kubernetes",
    "hosts": [
      "10.0.0.1",
      "127.0.0.1",
      "192.168.24.21",
      "192.168.24.22",
      "192.168.24.23",
      "localhost"
    ],
    "key": {
        "algo": "rsa",
        "size": 2048
    },
    "names": [
        {
            "C": "CN",
            "L": "BeiJing",
            "ST": "BeiJing",
            "O": "system:kube-controller-manager",
            "OU": "System"
        }
    ]
}
EOF

(3) hosts 列表包含所有 kube-controller-manager 节点 IP;
(4) CN 为 system:kube-controller-manager;O 为 system:kube-controller-manager;kube-apiserver预定义的 RBAC使用的ClusterRoleBindings system:kube-controller-manager将用户system:kube-controller-manager与ClusterRole system:kube-controller-manager绑定。
生成kube-controller-manager证书与私钥

cfssl gencert -ca=/opt/kubernetes/ssl/ca.pem \
     -ca-key=/opt/kubernetes/ssl/ca-key.pem \
     -config=/opt/kubernetes/ssl/ca-config.json \
     -profile=kubernetes kube-controller-manager-csr.json | cfssljson -bare kube-controller-manager

部署Master Node

从Github下载二进制文件

下载地址
注:打开链接你会发现里面有很多包,下载一个server包就够了,包含了Master和Worker Node二进制文件。

解压二进制包

tar zxvf kubernetes-server-linux-amd64.tar.gz
cd kubernetes/server/bin
cp kube-apiserver kube-scheduler kube-controller-manager kubectl /opt/kubernetes/bin
ln -sf /opt/kubernetes/bin/kubectl /usr/bin/kubectl

部署kube-apiserver

  1. 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://192.168.24.21:2379,https://192.168.24.22:2379,https://192.168.24.23:2379 \\
--bind-address=192.168.24.21 \\
--secure-port=6443 \\
--advertise-address=192.168.24.21 \\
--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-signing-key-file=/opt/kubernetes/ssl/ca-key.pem \\
--service-account-issuer=https://192.168.24.21:6443 \\
--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: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
–etcd-xxxfile:连接Etcd集群证书
–audit-log-xxx:审计日志

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

  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 \\
--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

  1. 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
  1. 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

  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 \
--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)
2. 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
  1. 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

所有组件都已经启动成功,通过kubectl工具查看当前集群组件状态:

~# kubectl get cs
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok                  
controller-manager   Healthy   ok                  
etcd-2               Healthy   {"health":"true"}   
etcd-1               Healthy   {"health":"true"}   
etcd-0               Healthy   {"health":"true"}  

如上输出说明Master节点组件运行正常。

部署其他节点

  1. 拷贝应用
scp /opt/kubernetes root@192.168.24.22:/opt
scp -r /usr/lib/systemd/system/kube-* root@192.168.24.22:/usr/lib/systemd/system
scp /opt/kubernetes root@192.168.24.22:/opt
scp -r /usr/lib/systemd/system/kube-* root@192.168.24.23:/usr/lib/systemd/system
  1. 修改/opt/kubernetes/cfg/kube-apiserver.conf配置文件为本地IP:
vim /opt/kubernetes/cfg/kube-apiserver.conf
  1. kubectl软链接到/usr/bin
ln -sf /opt/kubernetes/bin/kubectl /usr/bin/kubectl

部署Worker Node

创建工作目录并拷贝二进制文件

  1. 在所有worker node创建工作目录:
mkdir -p /opt/kubernetes/{bin,cfg,ssl,logs} 
  1. 从master节点拷贝:
cd kubernetes/server/bin
cp kubelet kube-proxy kubectl /opt/kubernetes/bin   # 本地拷贝
ln -sf /opt/kubernetes/bin/kubectl /usr/bin/kubectl
  1. 从master节点拷贝ssl证书
cp -r /opt/kubernetes/ssl/* rainbond@192.168.24.24:/opt/kubernetes/ssl/

部署kubelet

  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 \\
--address=192.168.24.24 \\
--hostname-override=node-04 \\
--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

  1. 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
  1. 生成bootstrap.kubeconfig文件
cd /opt/kubernetes/cfg/

KUBE_APISERVER="https://192.168.24.21:6443" # apiserver IP:PORT
TOKEN="c47ffb939f5ca36231d9e3121a252940" # 与token.csv里保持一致
NODE_ADDRESS="192.168.24.24"
DNS_SERVER_IP="223.5.5.5"

# 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
  1. 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
  1. 启动并设置开机启动
systemctl daemon-reload
systemctl start kubelet
systemctl enable kubelet

6 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-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A   6m3s   kubernetes.io/kube-apiserver-client-kubelet   kubelet-bootstrap   Pending

# 批准申请
kubectl certificate approve node-csr-uCEGPOIiDdlLODKts8J658HrFq9CZ--K6M4G7bjhk8A

# 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

  1. 创建配置文件
cat > /opt/kubernetes/cfg/kube-proxy.conf << EOF
KUBE_PROXY_OPTS="--logtostderr=false \\
--v=4 \\
--log-dir=/opt/kubernetes/logs \\
--config=/opt/kubernetes/cfg/kube-proxy-config.yml"
EOF
  1. 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: node-04
clusterCIDR: 10.0.0.0/24
EOF
  1. 生成kube-proxy.kubeconfig文件
    生成kube-proxy证书:
# 切换工作目录
cd /opt/kubernetes/ssl

# 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

ls kube-proxy*pem
kube-proxy-key.pem  kube-proxy.pem

生成kubeconfig文件:

cd /opt/kubernetes/cfg
KUBE_APISERVER="https://192.168.24.21:6443"

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=/opt/kubernetes/ssl/kube-proxy.pem \
  --client-key=/opt/kubernetes/ssl/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. systemd管理kube-proxy
cat > /usr/lib/systemd/system/kube-proxy.service << EOF
[Unit]
Description=Kubernetes Proxy
After=network.target
[Service]
User=root
Group=root
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二进制文件:
下载地址
解压二进制包并移动到默认工作目录:

mkdir -p /opt/cni/bin

tar zxvf cni-plugins-linux-amd64-v0.9.0.tgz -C /opt/cni/bin

说明:本步骤在master node上执行
部署CNI网络:

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

默认镜像地址无法访问,修改为docker hub镜像仓库。

kubectl apply -f kube-flannel.yml

kubectl get pods -n kube-system
NAME                          READY   STATUS    RESTARTS   AGE
kube-flannel-ds-amd64-2pc95   1/1     Running   0          72s

kubectl get node
NAME         STATUS   ROLES    AGE   VERSION
k8s-master   Ready    <none>   41m   v1.18.3

部署好网络插件,Node准备就绪。

授权apiserver访问kubelet

说明:本步骤在master node上执行

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

flannel部署(说明:未验证)

参考见flannel网络、为node节点创建kubeconfig文件
以下操作在所有的node节点上均执行一次
设置flannel配置文件

cat <<EOF >/opt/kubernetes/cfg/flanneld
FLANNEL_OPTIONS="--etcd-endpoints=https://192.168.1.24.21:2379,https://192.168.1.24.21:2379,https://192.168.1.24.21:2379 \
-etcd-cafile=/opt/kubernetes/ssl/ca.pem \
-etcd-certfile=/opt/kubernetes/ssl/server.pem \
-etcd-keyfile=/opt/kubernetes/ssl/server-key.pem"
EOF

设置flannel服务启动文件

cat <<EOF >/usr/lib/systemd/system/flanneld.service
[Unit]
Description=Flanneld overlay address etcd agent
After=network-online.target network.target
Before=docker.service

[Service]
Type=notify
EnvironmentFile=/opt/kubernetes/cfg/flanneld
ExecStart=/opt/kubernetes/bin/flanneld --ip-masq \$FLANNEL_OPTIONS
ExecStartPost=/opt/kubernetes/bin/mk-docker-opts.sh -k DOCKER_NETWORK_OPTIONS -d /run/flannel/subnet.env
Restart=on-failure

[Install]
WantedBy=multi-user.target

EOF

重新设置docker启动文件

cat <<EOF >/usr/lib/systemd/system/docker.service

[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
After=network-online.target firewalld.service
Wants=network-online.target

[Service]
Type=notify
EnvironmentFile=/run/flannel/subnet.env
ExecStart=/usr/bin/dockerd  \$DOCKER_NETWORK_OPTIONS
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

写入分配的子网段到etcd,供flanneld使用

/opt/kubernetes/bin/etcdctl --ca-file=ca.pem --cert-file=server.pem --key-file=server-key.pem --endpoints="https://10.10.99.225:2379,https://10.10.99.228:2379,https://192.168.0.10.10.99.233:2379" set /coreos.com/network/config '{ "Network": "172.17.0.0/16", "Backend": {"Type": "vxlan"}}'

/opt/kubernetes/bin/etcdctl --ca-file=ca.pem --cert-file=server.pem --key-file=server-key.pem --endpoints="https://10.10.99.225:2379,https://10.10.99.228:2379,https://192.168.0.10.10.99.233:2379" get /coreos.com/network/config

在一个etcd节点上执行就可以,会同步到其他etcd节点上。这里指定了flannel的网段为172.17网段,采用vxlan模式。

启动flannel

systemctl daemon-reload
systemctl start flanneld.service
systemctl enable flanneld.service

启动之后会生成一个flannel的虚拟网卡
这里写图片描述

重启docker
systemctl restart docker

新增加Worker Node

  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192.168.24.25/26
scp -r /opt/kubernetes root@192.168.24.25:/opt/
scp -r /usr/lib/systemd/system/{kubelet,kube-proxy}.service root@192.168.24.25:/usr/lib/systemd/system
scp -r /opt/cni/ root@192.168.24.25:/opt/
  1. 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。

  1. 修改主机名
vi /opt/kubernetes/cfg/kubelet.conf
--address=192.168.24.25
--hostname-override=node-05

vi /opt/kubernetes/cfg/kube-proxy-config.yml
--address=192.168.24.26
--hostnameOverride: node-06
  1. 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
  1. 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
  1. 查看Node状态
kubectl get node
NAME         STATUS     ROLES    AGE   VERSION
k8s-master   Ready      <none>   65m   v1.18.3
k8s-node1    Ready      <none>   12m   v1.18.3
k8s-node2    Ready      <none>   81s   v1.18.3

Node2(192.168.24.26 )节点同上。记得修改主机名!

部署Dashboard和CoreDNS

部署Dashboard

git clone https://github.com/kubernetes/dashboard.git
cd dashboard
git checkout v2.0.3
cd aio/deploy/

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

kubectl apply -f recommended.yaml
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
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。

部署CoreDNS

CoreDNS用于集群内部Service名称解析。
部署coredns

安装常见问题

1.报错信息

 failed to run Kubelet: cannot create certificate signing request: certificatesigningrequests.certificates.k8s.io is forbidden: User "kubelet-bootstrap" cannot create resource "certificatesigningrequests" in API group "certificates.k8s.io" at the cluster scope

原因:kubelet-bootstrap并没有权限创建证书。所以要创建这个用户的权限并绑定到这个角色上。参考见k8s集群部署四:node节点组件部署
解决方法是在master上执行

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

K8S/Kubernetes社区为您提供最前沿的新闻资讯和知识内容

更多推荐