kubernetes学习 | 集群环境搭建
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学习笔记

1257 字
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27 分钟
Table of Contents

安装要求

此次采用kubeadm实现集群安装。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

安装步骤

  • 创建一个Master 节点kubeadm init
  • 将Node 节点加入到当前集群中$ kubeadm join <Master 节点的IP 和端口>

安装要求

  • 一台或多台机器，操作系统CentOS7.x-86_x64
  • 硬件配置：2GB 或更多RAM，2 个CPU 或更多CPU，硬盘30GB 或更多
  • 集群中所有机器之间网络互通
  • 可以访问外网，需要拉取镜像
  • 禁止swap 分区

最终目标

  • 在所有节点上安装Docker 和kubeadm
  • 部署Kubernetes Master
  • 部署容器网络插件
  • 部署Kubernetes Node，将节点加入Kubernetes 集群中
  • 部署Dashboard Web 页面，可视化查看Kubernetes 资源

准备环境

角色 IP地址 组件
k8s-master01 192.168.152.142 docker，kubectl，kubeadm，kubelet
k8s-node01 192.168.152.143 docker，kubectl，kubeadm，kubelet
k8s-node02 192.168.152.144 docker，kubectl，kubeadm，kubelet

三台主机系统版本 CentOS Linux release 7.4.1708 (Core)

系统初始化

  1. 主机域名解析 在三台主机的/etc/hosts文件中分别配置主机名解析。在企业汇总推荐使用内部DNS服务器来解析。
192.168.152.146 k8s-master1
192.168.152.147 k8s-node1
192.168.152.148 k8s-node2

  1. 调整系统时区，每台电脑都要调整。

    # 设置系统时区为 中国/上海
timedatectl set-timezone Asia/Shanghai
# 将当前的 UTC 时间写入硬件时钟
timedatectl set-local-rtc 0
# 重启依赖于系统时间的服务
systemctl restart rsyslog
systemctl restart crond

  2. 禁用iptables和firewalld服务
    K8s和docker在运行中会产生大量的iptables规则，为了不让系统规则跟他们混淆，直接关闭系统的规则

#关闭firewalld服务
systemctl stop firewalld
systemctl disable firewalld

#关闭iptables服务
systemctl stop iptables
systemctl disable iptables

  1. 关闭 SELINUX（所有节点都要操作）
    在/etc/selinux/config里面关闭

    # This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of three two values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected. 
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted

  2. 禁止swap分区

    vim /etc/fstab
# /dev/mapper/centos-swap swap                    swap    defaults        0 0

  3. 调整内核参数
    在/etc/sysctl.d/目录下创建文件

    cat <<EOF> kubernetes.conf 
net.bridge.bridge-nf-call-iptables=1
net.bridge.bridge-nf-call-ip6tables=1
net.ipv4.ip_forward=1
net.ipv4.tcp_tw_recycle=0
vm.swappiness=0 # 禁止使用 swap 空间，只有当系统 OOM 时才允许使用它
vm.overcommit_memory=1 # 不检查物理内存是否够用
vm.panic_on_oom=0 # 开启 OOM
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

使加载生效

#如果出现加载报错，未找到文件夹，就先执行下面两个命令
# lsmod |grep conntrack
# modprobe ip_conntrack
sysctl -p /etc/sysctl.d/kubernetes.conf

#加载网桥过滤模块
modprobe br_netfilter
  1. kube-proxy开启ipvs的前置条件
# 安装ipset和ipvsadm
yum install ipset ipvsadmin -y

#添加需要加载的模块写入脚本文件
cat <<EOF> /etc/sysconfig/modules/ipvs.modules 
#!/bin/bash
modprobe -- ip_vs
modprobe -- ip_vs_rr
modprobe -- ip_vs_wrr
modprobe -- ip_vs_sh
modprobe -- nf_conntrack_ipv4
EOF

#为脚本文件添加执行权限
chmod 755 /etc/sysconfig/modules/ipvs.modules
#执行脚本文件
bash /etc/sysconfig/modules/ipvs.modules
#查看对应的模块是否加载成功
lsmod | grep -e ip_vs -e nf_conntrack_ipv4

安装docker

  1. 切换镜像源
yum install -y yum-utils device-mapper-persistent-data lvm2

yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

#安装指定docker版本
yum install -y --setopt=obsoletes=0 -y docker-ce-18.09.9-3.el7

#配置docker加速器
## 创建 /etc/docker 目录
mkdir /etc/docker

cat > /etc/docker/daemon.json <<EOF
{
"exec-opts": ["native.cgroupdriver=systemd"],
"log-driver": "json-file",
"log-opts": {
"max-size": "100m"
}
}
EOF
mkdir -p /etc/systemd/system/docker.service.d
# 重启docker服务
systemctl daemon-reload && systemctl restart docker && systemctl enable docker

安装k8s组件

  1. 配置k8s镜像源地址

    cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=http://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg
http://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

  2. 安装k8s组件并指定版本号

    yum install -y kubelet-1.20.9 kubeadm-1.20.9 kubectl-1.20.9 --disableexcludes=kubernetes

  3. 配置kubelet的cgroup
    编辑/etc/sysconfig/kubelet,添加以下配置：

    KUBELET_CGROUP_ARGS="--cgroup-driver=systemd"
KUBE_PROXY_MODE="ipvs"

集群初始化

  1. 下载k8s镜像
    可以通过kubeadm config image list 查看所需镜像及版本
sudo tee ./images.sh <<-'EOF'
#!/bin/bash
images=(
kube-apiserver:v1.20.9
kube-proxy:v1.20.9
kube-controller-manager:v1.20.9
kube-scheduler:v1.20.9
coredns:1.7.0
etcd:3.4.13-0
pause:3.2
)
for imageName in ${images[@]} ; do
docker pull registry.cn-hangzhou.aliyuncs.com/XXX_k8s_images/$imageName
done
EOF

chmod +x ./images.sh && ./images.sh

XXX处为隐私信息。具体镜像自行下载。

  1. 初始化主节点（在主节点创建）
kubeadm init --kubernetes-version=1.20.0 --apiserver-advertise-address=192.168.152.146 --image-repository registry.aliyuncs.com/google_containers --service-cidr=10.96.0.0/12 --pod-network-cidr=10.244.0.0/16

执行完成后，可以把任意工作节加入主节点

  1. 把两台工作节点加进来
kubeadm join 192.168.152.146:6443 --token l9w4o2.aupecrr3sf17jf5q \
    --discovery-token-ca-cert-hash sha256:e3ba5d155bcc64df271b6d6b07bdd06bd3647c8a517a532288c3d31b1d74cc87
  1. 安装网络插件calico（在主节点部署）
curl https://docs.projectcalico.org/v3.20/manifests/calico.yaml -O
kubectl apply -f calico.yaml

随后查看节点状态：

file

  1. 部署dashboard

由于网络原因，所以本地写好yaml文件，通过kubectl apply -f 来部署，以下是配置文件

# Copyright 2017 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

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

---

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

---

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

---

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

---

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

---

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

---

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

---

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

---

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

---

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

---

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

---

kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
    spec:
      containers:
        - name: kubernetes-dashboard
          image: kubernetesui/dashboard:v2.3.1
          imagePullPolicy: Always
          ports:
            - containerPort: 8443
              protocol: TCP
          args:
            - --auto-generate-certificates
            - --namespace=kubernetes-dashboard
            # Uncomment the following line to manually specify Kubernetes API server Host
            # If not specified, Dashboard will attempt to auto discover the API server and connect
            # to it. Uncomment only if the default does not work.
            # - --apiserver-host=http://my-address:port
          volumeMounts:
            - name: kubernetes-dashboard-certs
              mountPath: /certs
              # Create on-disk volume to store exec logs
            - mountPath: /tmp
              name: tmp-volume
          livenessProbe:
            httpGet:
              scheme: HTTPS
              path: /
              port: 8443
            initialDelaySeconds: 30
            timeoutSeconds: 30
          securityContext:
            allowPrivilegeEscalation: false
            readOnlyRootFilesystem: true
            runAsUser: 1001
            runAsGroup: 2001
      volumes:
        - name: kubernetes-dashboard-certs
          secret:
            secretName: kubernetes-dashboard-certs
        - name: tmp-volume
          emptyDir: {}
      serviceAccountName: kubernetes-dashboard
      nodeSelector:
        "kubernetes.io/os": linux
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
        - key: node-role.kubernetes.io/master
          effect: NoSchedule

---

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

---

kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: dashboard-metrics-scraper
  name: dashboard-metrics-scraper
  namespace: kubernetes-dashboard
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: dashboard-metrics-scraper
  template:
    metadata:
      labels:
        k8s-app: dashboard-metrics-scraper
      annotations:
        seccomp.security.alpha.kubernetes.io/pod: 'runtime/default'
    spec:
      containers:
        - name: dashboard-metrics-scraper
          image: kubernetesui/metrics-scraper:v1.0.6
          ports:
            - containerPort: 8000
              protocol: TCP
          livenessProbe:
            httpGet:
              scheme: HTTP
              path: /
              port: 8000
            initialDelaySeconds: 30
            timeoutSeconds: 30
          volumeMounts:
          - mountPath: /tmp
            name: tmp-volume
          securityContext:
            allowPrivilegeEscalation: false
            readOnlyRootFilesystem: true
            runAsUser: 1001
            runAsGroup: 2001
      serviceAccountName: kubernetes-dashboard
      nodeSelector:
        "kubernetes.io/os": linux
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
        - key: node-role.kubernetes.io/master
          effect: NoSchedule
      volumes:
        - name: tmp-volume
          emptyDir: {}

设置访问端口

kubectl edit svc kubernetes-dashboard -n kubernetes-dashboard

type: ClusterIP 改为 type: NodePort

kubectl get svc -A |grep kubernetes-dashboard
## 找到端口，在安全组放行

创建登录dashboard的账号，同样通过kubectl apply -f来部署

#创建访问账号，准备一个yaml文件； vi dash.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kubernetes-dashboard
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kubernetes-dashboard

获取访问令牌

#获取访问令牌
kubectl -n kubernetes-dashboard get secret $(kubectl -n kubernetes-dashboard get sa/admin-user -o jsonpath="{.secrets[0].name}") -o go-template="{{.data.token | base64decode}}"

访问：任意节点IP+端口访问，dashboard采用https访问协议

file

注

以上参考HM和SGG的学习视频笔记，此篇文章只做学习记录，无其他盈利目的。
如有错误，欢迎指出

k8s

评论

  1. xiaocc
    博主
    7 月前
    2024-4-20 14:29:30

    你写的太棒啦

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