使用kubeadm在CentOS 7上部署kubernetes1.18

时间：2022-12-30 15:57:58

一、Kubernetes简介

Kubernetes（简称K8S）是开源的容器集群管理系统，可以实现容器集群的自动化部署、自动扩缩容、维护等功能。它既是一款容器编排工具，也是全新的基于容器技术的分布式架构领先方案。在Docker技术的基础上，为容器化的应用提供部署运行、资源调度、服务发现和动态伸缩等功能，提高了大规模容器集群管理的便捷性。

K8S集群中有管理节点与工作节点两种类型。管理节点主要负责K8S集群管理，集群中各节点间的信息交互、任务调度，还负责容器、Pod、NameSpaces、PV等生命周期的管理。工作节点主要为容器和Pod提供计算资源，Pod及容器全部运行在工作节点上，工作节点通过kubelet服务与管理节点通信以管理容器的生命周期，并与集群其他节点进行通信。

使用kubeadm在CentOS 7上部署kubernetes1.18

二、系统准备

1、查看系统版本

[root@localhost ~]# cat /etc/redhat-release

CentOS Linux release 7.8.2003 (Core)

2、配置固定IP

[root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens32

  1. # Generated by parse-kickstart
  2. DEVICE="ens32"
  3. IPV6INIT="no"
  4. BOOTPROTO="static"
  5. UUID="94513ff2-d82f-4409-9fe9-d29beda7c9f9"
  6. ONBOOT="yes"
  7. IPADDR=172.168.1.244
  8. NETMASK=255.255.255.0
  9. GATEWAY=172.168.1.254
  10. DNS1=202.96.134.133
  11. DNS2=114.114.114.114

3、配置主机名

[root@localhost ~]# hostnamectl set-hostname Master --static

[root@localhost ~]# su -

[root@Master ~]# echo "172.168.1.244 Master" >>/etc/hosts

4、关闭swap，注释swap分区

[root@Master ~]# swapoff -a

[root@Master ~]# cat /etc/fstab

  1. #
  2. # /etc/fstab
  3. # Created by anaconda on Wed Aug 26 11:35:24 2020
  4. #
  5. # Accessible filesystems, by reference, are maintained under '/dev/disk'
  6. # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
  7. #
  8. UUID=28b815c0-6d1f-470d-b52c-6ececdd015ab / xfs defaults 0 0
  9. UUID=6913149f-a6c7-487f-a0ff-0aea30cf9aa8 /boot xfs defaults 0 0
  10. #UUID=80720715-69f0-4d0f-b1f8-151e963dcfde swap swap defaults 0 0

5、配置内核参数，将桥接的IPv4流量传递到iptables的链

[root@Master ~]# cat > /etc/sysctl.d/k8s.conf <<EOF

net.bridge.bridge-nf-call-ip6tables = 1

net.bridge.bridge-nf-call-iptables = 1

EOF

[root@Master ~]# sysctl --system

6、安装Docker

[root@Master ~]# curl -fsSL https://get.docker.com | bash -s docker --mirror Aliyun

[root@Master ~]# systemctl enable docker

[root@Master ~]# systemctl start docker

7、添加阿里云docker仓库加速器

[root@Master ~]# mkdir -p /etc/docker

[root@Master ~]# cat >/etc/docker/daemon.json <<EOF

{

"registry-mirrors": ["https://fl791z1h.mirror.aliyuncs.com"]

}

EOF

[root@Master ~]# systemctl daemon-reload

[root@Master ~]# systemctl restart docker

三、安装kubectl、kubelet、kubeadm

1、添加阿里kubernetes源

[root@Master ~]# cat > /etc/yum.repos.d/kubernetes.repo <<EOF

[kubernetes]

name=Kubernetes

baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/

enabled=1

gpgcheck=1

repo_gpgcheck=1

gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg

EOF

2、安装kubectl、kubelet、kubeadm

[root@Master ~]# yum -y install kubectl kubelet kubeadm

[root@Master ~]# systemctl enable kubelet

3、初始化k8s集群

[root@Master ~]# kubeadm init --kubernetes-version=1.18.0 \

--apiserver-advertise-address=172.168.1.244 \

--image-repository registry.aliyuncs.com/google_containers \

--service-cidr=10.10.0.0/16 --pod-network-cidr=10.122.0.0/16

注：pod的网段为: 10.122.0.0/16，api server地址为Master本机IP，网段可以自定义，不冲突即可。

这一步很关键，由于kubeadm 默认从官网k8s.grc.io下载所需镜像，国内无法访问，因此需要通过–image-repository指定阿里云镜像仓库地址。

集群初始化成功后返回如下信息：

  1. W0827 09:39:27.978003 18574 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet
  2. .config.k8s.io kubeproxy.config.k8s.io][init] Using Kubernetes version: v1.18.0
  3. [preflight] Running pre-flight checks
  4. [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "system
  5. d". Please follow the guide at https://kubernetes.io/docs/setup/cri/[preflight] Pulling images required for setting up a Kubernetes cluster
  6. [preflight] This might take a minute or two, depending on the speed of your internet connection
  7. [preflight] You can also perform this action in beforehand using 'kubeadm config images pull'
  8. [kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
  9. [kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
  10. [kubelet-start] Starting the kubelet
  11. [certs] Using certificateDir folder "/etc/kubernetes/pki"
  12. [certs] Generating "ca" certificate and key
  13. [certs] Generating "apiserver" certificate and key
  14. [certs] apiserver serving cert is signed for DNS names [master kubernetes kubernetes.default kubernetes.default.svc kubern
  15. etes.default.svc.cluster.local] and IPs [10.10.0.1 172.168.1.244][certs] Generating "apiserver-kubelet-client" certificate and key
  16. [certs] Generating "front-proxy-ca" certificate and key
  17. [certs] Generating "front-proxy-client" certificate and key
  18. [certs] Generating "etcd/ca" certificate and key
  19. [certs] Generating "etcd/server" certificate and key
  20. [certs] etcd/server serving cert is signed for DNS names [master localhost] and IPs [172.168.1.244 127.0.0.1 ::1]
  21. [certs] Generating "etcd/peer" certificate and key
  22. [certs] etcd/peer serving cert is signed for DNS names [master localhost] and IPs [172.168.1.244 127.0.0.1 ::1]
  23. [certs] Generating "etcd/healthcheck-client" certificate and key
  24. [certs] Generating "apiserver-etcd-client" certificate and key
  25. [certs] Generating "sa" key and public key
  26. [kubeconfig] Using kubeconfig folder "/etc/kubernetes"
  27. [kubeconfig] Writing "admin.conf" kubeconfig file
  28. [kubeconfig] Writing "kubelet.conf" kubeconfig file
  29. [kubeconfig] Writing "controller-manager.conf" kubeconfig file
  30. [kubeconfig] Writing "scheduler.conf" kubeconfig file
  31. [control-plane] Using manifest folder "/etc/kubernetes/manifests"
  32. [control-plane] Creating static Pod manifest for "kube-apiserver"
  33. [control-plane] Creating static Pod manifest for "kube-controller-manager"
  34. W0827 09:40:40.567020 18574 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,
  35. RBAC"[control-plane] Creating static Pod manifest for "kube-scheduler"
  36. W0827 09:40:40.568440 18574 manifests.go:225] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,
  37. RBAC"[etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"
  38. [wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/m
  39. anifests". This can take up to 4m0s[apiclient] All control plane components are healthy after 21.002990 seconds
  40. [upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
  41. [kubelet] Creating a ConfigMap "kubelet-config-1.18" in namespace kube-system with the configuration for the kubelets in t
  42. he cluster[upload-certs] Skipping phase. Please see --upload-certs
  43. [mark-control-plane] Marking the node master as control-plane by adding the label "node-role.kubernetes.io/master=''"
  44. [mark-control-plane] Marking the node master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSched
  45. ule][bootstrap-token] Using token: islm9c.f9rolarxnlnfn4rz
  46. [bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
  47. [bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
  48. [bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term ce
  49. rtificate credentials[bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstr
  50. ap Token[bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster
  51. [bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace
  52. [kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
  53. [addons] Applied essential addon: CoreDNS
  54. [addons] Applied essential addon: kube-proxy

  56. Your Kubernetes control-plane has initialized successfully!

  58. To start using your cluster, you need to run the following as a regular user:

  60. mkdir -p $HOME/.kube
  61. sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  62. sudo chown $(id -u):$(id -g) $HOME/.kube/config

  64. You should now deploy a pod network to the cluster.
  65. Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  66. https://kubernetes.io/docs/concepts/cluster-administration/addons/

  68. Then you can join any number of worker nodes by running the following on each as root:

  70. kubeadm join 172.168.1.244:6443 --token islm9c.f9rolarxnlnfn4rz \
  71. --discovery-token-ca-cert-hash sha256:41b976bd9e5f8fe1a81d1c3b4dcb33a06dafb0ab3d6de036950ceda1edb4ab6c

记录生成的最后部分内容，此内容需要在其它节点加入Kubernetes集群时执行。

4、根据提示创建kubectl

[root@Master ~]# mkdir -p $HOME/.kube

[root@Master ~]# sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

[root@Master ~]# sudo chown $(id -u):$(id -g) $HOME/.kube/config

5、执行下面命令，使kubectl可以自动补充

[root@Master ~]# source <(kubectl completion bash)

6、查看node节点和pod

[root@Master ~]# kubectl get node

  1. NAME STATUS ROLES AGE VERSION
  2. master NotReady master 6m41s v1.18.8

[root@Master ~]# kubectl get pod --all-namespaces

  1. NAMESPACE NAME READY STATUS RESTARTS AGE
  2. kube-system coredns-7ff77c879f-njmcq 0/1 Pending 0 6m30s
  3. kube-system coredns-7ff77c879f-pq5c6 0/1 Pending 0 6m30s
  4. kube-system etcd-master 1/1 Running 0 6m39s
  5. kube-system kube-apiserver-master 1/1 Running 0 6m39s
  6. kube-system kube-controller-manager-master 1/1 Running 0 6m39s
  7. kube-system kube-proxy-74j9n 1/1 Running 0 6m30s
  8. kube-system kube-scheduler-master 1/1 Running 0 6m39s

node节点为NotReady，因为corednspod没有启动，缺少网络pod

7、安装calico网络

[root@Master ~]# kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml

configmap/calico-config created

customresourcedefinition.apiextensions.k8s.io/bgpconfigurations.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/bgppeers.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/blockaffinities.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/clusterinformations.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/felixconfigurations.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/globalnetworkpolicies.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/globalnetworksets.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/hostendpoints.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/ipamblocks.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/ipamconfigs.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/ipamhandles.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/ippools.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/kubecontrollersconfigurations.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/networkpolicies.crd.projectcalico.org created

customresourcedefinition.apiextensions.k8s.io/networksets.crd.projectcalico.org created

clusterrole.rbac.authorization.k8s.io/calico-kube-controllers created

clusterrolebinding.rbac.authorization.k8s.io/calico-kube-controllers created

clusterrole.rbac.authorization.k8s.io/calico-node created

clusterrolebinding.rbac.authorization.k8s.io/calico-node created

daemonset.apps/calico-node created

serviceaccount/calico-node created

deployment.apps/calico-kube-controllers created

serviceaccount/calico-kube-controllers created

8、再次查看pod和node

[root@Master ~]# kubectl get pod --all-namespaces

  1. NAMESPACE NAME READY STATUS RESTARTS AGE
  2. kube-system calico-kube-controllers-5447dc9cbf-sxvxd 1/1 Running 0 7m33s
  3. kube-system calico-node-g2txc 1/1 Running 0 7m33s
  4. kube-system coredns-7ff77c879f-njmcq 1/1 Running 0 14m
  5. kube-system coredns-7ff77c879f-pq5c6 1/1 Running 0 14m
  6. kube-system etcd-master 1/1 Running 0 14m
  7. kube-system kube-apiserver-master 1/1 Running 0 14m
  8. kube-system kube-controller-manager-master 1/1 Running 0 14m
  9. kube-system kube-proxy-74j9n 1/1 Running 0 14m
  10. kube-system kube-scheduler-master 1/1 Running 0 14m

[root@Master ~]# kubectl get node

  1. NAME STATUS ROLES AGE VERSION
  2. master Ready master 15m v1.18.8

此时集群状态正常

9、安装kubernetes-dashboard

官方部署dashboard的服务没使用nodeport，将yaml文件下载到本地，在service里添加nodeport

[root@Master ~]# wget https://raw.githubusercontent.com/kubernetes/dashboard/v2.0.0-rc7/aio/deploy/recommended.yaml

添加nodeport

[root@Master ~]# cat recommended.yaml

  1. kind: Service
  2. apiVersion: v1
  3. metadata:
  4. labels:
  5. k8s-app: kubernetes-dashboard
  6. name: kubernetes-dashboard
  7. namespace: kubernetes-dashboardspec:
  8. type: NodePort
  9. ports:
  10. - port: 443
  11. targetPort: 8443
  12. nodePort: 30000
  13. selector:
  14. k8s-app: kubernetes-dashboard

或者直接下载备用地址（因为官方我下载不了，我上传到我的服务器了，下载直接使用，不需要添加nodeport端口）

[root@Master ~]# wget https://mirrors.yangxingzhen.com/kubernetes/recommended.yaml

[root@Master ~]# kubectl create -f recommended.yaml

namespace/kubernetes-dashboard created

serviceaccount/kubernetes-dashboard created

service/kubernetes-dashboard created

secret/kubernetes-dashboard-certs created

secret/kubernetes-dashboard-csrf created

secret/kubernetes-dashboard-key-holder created

configmap/kubernetes-dashboard-settings created

role.rbac.authorization.k8s.io/kubernetes-dashboard created

clusterrole.rbac.authorization.k8s.io/kubernetes-dashboard created

rolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created

clusterrolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created

deployment.apps/kubernetes-dashboard created

service/dashboard-metrics-scraper created

deployment.apps/dashboard-metrics-scraper created

10、查看pod和service

[root@Master ~]# kubectl get pod --all-namespaces

[root@Master ~]# kubectl get svc -n kubernetes-dashboard

使用kubeadm在CentOS 7上部署kubernetes1.18

11、通过页面访问，推荐使用firefox浏览器

浏览器输入https://172.168.1.244:30000/

使用kubeadm在CentOS 7上部署kubernetes1.18

查看凭证

[root@Master ~]# kubectl -n kubernetes-dashboard get secret

使用token进行登录，执行下面命令获取token

[root@Master ~]# kubectl describe secrets -n kubernetes-dashboard kubernetes-dashboard-token-8g9g6 | grep token | awk 'NR==3{print $2}'

使用kubeadm在CentOS 7上部署kubernetes1.18

使用kubeadm在CentOS 7上部署kubernetes1.18

登录后如下展示，如果没有namespace可选，并且提示找不到资源 ，那么就是权限问题

使用kubeadm在CentOS 7上部署kubernetes1.18

12、通过查看dashboard日志，得到如下信息

[root@Master ~]# kubectl logs -f -n kubernetes-dashboard kubernetes-dashboard-5d4dc8b976-bjkjk

使用kubeadm在CentOS 7上部署kubernetes1.18

解决方法

[root@Master ~]# kubectl create clusterrolebinding serviceaccount-cluster-admin --clusterrole=cluster-admin --user=system:serviceaccount:kubernetes-dashboard:kubernetes-dashboard

此时再查看dashboard，即可看到有资源展示

使用kubeadm在CentOS 7上部署kubernetes1.18

至此，kubeadm在CentOS 7上部署kubernetes1.18完毕。

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