ubuntu16.0安装kubernetes集群为练习CKA准备

    技术2026-08-09  18

    报名

    CKA报名:https://training.linuxfoundation.cn/ 时间非常紧

    考试注意事项

    要保持头再摄像头范围内,让监考老师看到 要保持界面简洁 只能带透明水杯 可以上厕所,但要注意时间

    考试流程

    jumpserver 通过公网ip远程,通过私网ip远程其他机器。

    基础环境配置(all)

    swapoff -a cat <<EOF> /etc/hosts 192.168.211.40 master 192.168.211.41 node1 192.168.211.42 node2 EOF

    安装docker(all)

    如果你觉得默认ubutu默认源慢,可以更换aliyun源

    $ vim /etc/apt/sources.list deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiverse deb-src http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse $ apt-get update

    手动安装(all)

    https://www.runoob.com/docker/ubuntu-docker-install.html

    注意:安装docker一定要指定稳定得版本,否则,会出现兼容性稳定,我们不求新而求稳。

    $ apt-get install -y docker-ce=5:19.03.4~3-0~ubuntu-xenial docker-ce-cli=5:19.03.4~3-0~ubuntu-xenial containerd.io=1.2.10-3

    问题:

    Failed to fetch cdrom://Ubuntu-Server 16.04.6 LTS _Xenial Xerus_ - Release amd64 (20190226)/dists/xenial/main/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs

    解决方法: deb cdrom行注释掉

    $ vim /etc/apt/sources.list #deb cdrom:[Ubuntu-Server 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.3)]/ xenial main restricted

    添加docker配置文件,如果不那么保持严谨可以不用添加这一步。如果拉去镜像,最好配置国内得镜像源。

    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 systemctl daemon-reload systemctl start docker systemctl status docker

    安装kubernets(all)

    配置google kubernets源

    cat <<EOF >/etc/apt/sources.list.d/kubernetes.list deb http://apt.kubernetes.io/ kubernetes-xenial main EOF

    配置key

    curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -

    更新并安装

    apt-get update apt-get install -y kubelet kubeadm kubectl

    Kubectl 自动补全

    $ source <(kubectl completion bash) # setup autocomplete in bash, bash-completion package should be installed first. $ source <(kubectl completion zsh) # setup autocomplete in zsh

    如果我们无法访问google,可以考虑用aliyun源

    配置aliyun kubernets源

    cat <<EOF >/etc/apt/sources.list.d/kubernetes.list deb https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial main EOF

    验证:

    sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 6A030B21BA07F4FB

    配置key

    curl https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | sudo apt-key add -

    安装工具

    sudo apt-get update sudo apt-get install -y kubelet kubeadm kubectl sudo apt-mark hold kubelet kubeadm kubectl

    kubeadm创建集群master节点

    直接执行初始化会拉取镜像失败(master)

    kubeadm init --pod-network-cidr=192.168.0.0/16 --apiserver-advertise-address=192.168.211.40

    拉取镜像失败

    failed to pull image k8s.gcr.io/kube-apiserver:v1.12.2 failed to pull image k8s.gcr.io/kube-controller-manager:v1.12.2 failed to pull image k8s.gcr.io/kube-scheduler:v1.12.2 failed to pull image k8s.gcr.io/kube-proxy:v1.12.2 failed to pull image k8s.gcr.io/pause:3.1 failed to pull image k8s.gcr.io/etcd:3.2.24 failed to pull image k8s.gcr.io/coredns:1.2.2

    查看需要拉取得镜像(all)

    $ kubeadm config images list k8s.gcr.io/kube-apiserver:v1.18.5 k8s.gcr.io/kube-controller-manager:v1.18.5 k8s.gcr.io/kube-scheduler:v1.18.5 k8s.gcr.io/kube-proxy:v1.18.5 k8s.gcr.io/pause:3.2 k8s.gcr.io/etcd:3.4.3-0 k8s.gcr.io/coredns:1.6.7

    注意:这个列表显示的tag名字和镜像版本号,从Kubernetes v1.12+开始,镜像名后面不带 amd64, arm, arm64, ppc64le 这样的标识了

    生成默认kubeadm.conf文件(all)

    $ kubeadm config print init-defaults > kubeadm.conf

    6.3 绕过墙下载镜像方法(all) 注意这个配置文件默认会从google的镜像仓库地址k8s.gcr.io下载镜像,如果你没有科学上网,那么就会 下载不来。因此,我们通过下面的方法把地址改成国内的,比如用阿里的:

    sed -i "s/imageRepository: .*/imageRepository: registry.aliyuncs.com\/google_containers/g" kubeadm.conf

    6.4 指定kubeadm安装的Kubernetes版本

    sed -i "s/kubernetesVersion: .*/kubernetesVersion: v1.18.1/g" kubeadm.conf

    6.5 下载需要用到的镜像(all) kubeadm.conf修改好后,我们执行下面命令就可以自动从国内下载需要用到的镜像了:

    $ kubeadm config images pull --config kubeadm.conf

    重新初始化master节点

    $ kubeadm init --pod-network-cidr=192.168.0.0/16 --apiserver-advertise-address=192.168.211.40 mkdir -p $HOME/.kube sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config sudo chown $(id -u):$(id -g) $HOME/.kube/config You should now deploy a pod network to the cluster. Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at: https://kubernetes.io/docs/concepts/cluster-administration/addons/ Then you can join any number of worker nodes by running the following on each as root: kubeadm join 192.168.211.40:6443 --token yuqokz.7989i4qx5770obvp \ --discovery-token-ca-cert-hash sha256:167d0176ccd1c90b7373917940620fb7a48b245913eb25a05726345902f6213c

    把最后生成的命令记住 master执行:(master)

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

    node执行加入集群:(node)

    报错

    $ kubeadm join 192.168.211.40:6443 --token yuqokz.7989i4qx5770obvp --discovery-token-ca-cert-hash sha256:167d0176ccd1c90b7373917940620fb7a48b245913eb25a05726345902f6213c W0804 09:39:51.878220 8270 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set. [preflight] Running pre-flight checks error execution phase preflight: [preflight] Some fatal errors occurred: [ERROR FileAvailable--etc-kubernetes-kubelet.conf]: /etc/kubernetes/kubelet.conf already exists [ERROR FileAvailable--etc-kubernetes-bootstrap-kubelet.conf]: /etc/kubernetes/bootstrap-kubelet.conf already exists [ERROR FileAvailable--etc-kubernetes-pki-ca.crt]: /etc/kubernetes/pki/ca.crt already exists [preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...` To see the stack trace of this error execute with --v=5 or higher

    解决方法:

    $ kubeadm reset

    再次执行join加入集群

    $ kubeadm join 192.168.211.40:6443 --token yuqokz.7989i4qx5770obvp \ --discovery-token-ca-cert-hash sha256:167d0176ccd1c90b7373917940620fb7a48b245913eb25a05726345902f6213c W0804 09:47:01.922091 13137 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set. [preflight] Running pre-flight checks [preflight] Reading configuration from the cluster... [preflight] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml' [kubelet-start] Downloading configuration for the kubelet from the "kubelet-config-1.18" ConfigMap in the kube-system namespace [kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml" [kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env" [kubelet-start] Starting the kubelet [kubelet-start] Waiting for the kubelet to perform the TLS Bootstrap... This node has joined the cluster: * Certificate signing request was sent to apiserver and a response was received. * The Kubelet was informed of the new secure connection details. Run 'kubectl get nodes' on the control-plane to see this node join the cluster.

    默认token有效期为24小时,当过期之后,该token就不可用了。这时就需要重新创建token,操作如下:

    $ kubeadm token create --print-join-command

    master执行:

    root@master:~# kubectl get nodes NAME STATUS ROLES AGE VERSION master NotReady master 19m v1.18.6 node1 NotReady <none> 6m55s v1.18.6 node2 NotReady <none> 5m16s v1.18.6 root@master:~# kubectl get pods No resources found in default namespace. root@master:~# kubectl get pods -A NAMESPACE NAME READY STATUS RESTARTS AGE kube-system coredns-66bff467f8-2xmnt 0/1 Pending 0 21m kube-system coredns-66bff467f8-ghj2s 0/1 Pending 0 21m kube-system etcd-master 1/1 Running 0 22m kube-system kube-apiserver-master 1/1 Running 0 22m kube-system kube-controller-manager-master 1/1 Running 0 22m kube-system kube-proxy-dh46z 1/1 Running 0 7m35s kube-system kube-proxy-jq6cb 1/1 Running 0 21m kube-system kube-proxy-z6prp 1/1 Running 0 9m14s kube-system kube-scheduler-master 1/1 Running 0 22m

    node执行:

    root@node2:~# kubectl get nodes (卡住) root@node2:~# mkdir -p $HOME/.kube root@node2:~# scp root@192.168.211.40:/root/.kube/config /root/.kube/ root@node2:~# kubectl get pods -A NAMESPACE NAME READY STATUS RESTARTS AGE kube-system coredns-66bff467f8-2xmnt 0/1 Pending 0 29m kube-system coredns-66bff467f8-ghj2s 0/1 Pending 0 29m kube-system etcd-master 1/1 Running 0 29m kube-system kube-apiserver-master 1/1 Running 0 29m kube-system kube-controller-manager-master 1/1 Running 0 29m kube-system kube-proxy-dh46z 1/1 Running 0 14m kube-system kube-proxy-jq6cb 1/1 Running 0 29m kube-system kube-proxy-z6prp 1/1 Running 0 16m kube-system kube-scheduler-master 1/1 Running 0 29m

    安装网络calico

    $ kubectl apply -f https://docs.projectcalico.org/v3.10/manifests/calico.yaml configmap/calico-config created customresourcedefinition.apiextensions.k8s.io/felixconfigurations.crd.projectcalico.org created customresourcedefinition.apiextensions.k8s.io/ipamblocks.crd.projectcalico.org created customresourcedefinition.apiextensions.k8s.io/blockaffinities.crd.projectcalico.org created customresourcedefinition.apiextensions.k8s.io/ipamhandles.crd.projectcalico.org created customresourcedefinition.apiextensions.k8s.io/ipamconfigs.crd.projectcalico.org created customresourcedefinition.apiextensions.k8s.io/bgppeers.crd.projectcalico.org created customresourcedefinition.apiextensions.k8s.io/bgpconfigurations.crd.projectcalico.org created customresourcedefinition.apiextensions.k8s.io/ippools.crd.projectcalico.org created customresourcedefinition.apiextensions.k8s.io/hostendpoints.crd.projectcalico.org created customresourcedefinition.apiextensions.k8s.io/clusterinformations.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/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

    pod创建失败,删除重新载尝试一次

    $ kubectl delete -f https://docs.projectcalico.org/v3.10/manifests/calico.yaml $ kubectl apply -f https://docs.projectcalico.org/v3.10/manifests/calico.yaml

    可能是拉取镜像失败或者DNS问题,kubectl describe看一下

    kubectl describe pods <pod_name> -n <namespace>

    假如拉取镜像失败,手动尝试拉取

    docker pull xxx

    DNS问题,换用

    $ cat /etc/resolve.conf nameserver 114.114.114.114 #国内DNS

    最后查看pod是否创建成功

    kubectl get pods -A

    注意:内存要给足,否则也有可能使pod处于pending状态。

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