kubernetes(一)kubeadm安装

系统信息

角色 系统 CPU Core memory
master 18.04.1-Ubuntu 4 8G
slave 18.04.1-Ubuntu 4 4G

安装前准备(主节点和从节点都需要执行)

  1. 关闭swap

    sudo swapoff -a  
    sudo  sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
    
  2. 配置系统安装源和kubernetes安装源
    在/etc/apt/sources.list.d/ 追加以下两个文件

    cat > /etc/apt/sources.list.d/kubernetes.list << EOF
    deb https://mirrors.aliyun.com/kubernetes/apt kubernetes-xenial main
    EOF  
    
    cat > /etc/apt/sources.list.d/system.list << EOF
    deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted  
    deb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted  
    deb http://mirrors.aliyun.com/ubuntu/ bionic universe  
    deb http://mirrors.aliyun.com/ubuntu/ bionic-updates universe  
    deb http://mirrors.aliyun.com/ubuntu/ bionic multiverse  
    deb http://mirrors.aliyun.com/ubuntu/ bionic-updates multiverse  
    deb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiverse 
    EOF
    
    

    执行

    sudo apt-get update
    
    
  3. 安装依赖工具包

    apt install -y curl jq
    
    
  4. 安装kubernetes源的安全key

    suod curl -s https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | sudo apt-key add -  
    
    
  5. 安装docker

    1. 下载安装包
      containerd.io_1.2.6-3_amd64.deb
      docker-ce-cli_19.03.5_3-0_ubuntu-bionic_amd64.deb
      docker-ce_19.03.5_3-0_ubuntu-bionic_amd64.deb

    2. 使用 sudo dpkg -i 依次安装上面的三个包

    3. 追加docker用户组

      sudo groupadd docker
      
      
    4. 将当前用户追加到docker用户组

      sudo usermod -aG docker $USER 
      
      
    5. 使用户组生效

      newgrp docker 
      
      
    6. 设置docker开机启动

      sudo systemctl enable docker 
      
      

安装主节点 (在master节点上执行)

  1. 安装kubelet组件

    1. 获取可安装的kubernetes版本号

      apt-cache madison kubeadm 
      apt-cache madison kubelet 
      apt-cache madison kubectl 
      
      

      从返回列表中找一个自己要安装的版本号,我们以1.16.3-00为例

    2. 执行如下命令,开始安装

      sudo apt install -y kubelet=1.16.3-00 kubeadm=1.16.3-00 kubectl=1.16.3-00  
      
      
  2. 下载相关镜像
    使用如下命令获取需要的镜像

    chengf@chengf:~$ kubeadm config images list  
    W1126 21:01:07.767448   20606 version.go:101] could not fetch a Kubernetes version from the internet: unable to get URL "https://dl.k8s.io/release/stable-1.txt": Get https://dl.k8s.io/release/stable-1.txt: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)  
    W1126 21:01:07.767516   20606 version.go:102] falling back to the local client version: v1.16.3  
    k8s.gcr.io/kube-apiserver:v1.16.3  
    k8s.gcr.io/kube-controller-manager:v1.16.3  
    k8s.gcr.io/kube-scheduler:v1.16.3  
    k8s.gcr.io/kube-proxy:v1.16.3  
    k8s.gcr.io/pause:3.1  
    k8s.gcr.io/etcd:3.3.15-0  
    k8s.gcr.io/coredns:1.6.2  
    
    

    因为k8s.gcr.io在国内无法访问,所以我们需要提前将这些镜像下载好,并tag成kubernetes需要的镜像名称

    chengf@chengf:~$ docker images  
    REPOSITORY                                TAG                 IMAGE ID            CREATED             SIZE  
    kubeimage/kube-proxy-amd64                v1.16.3             9b65a0f78b09        13 days ago         86.1MB  
    k8s.gcr.io/kube-proxy                     v1.16.3             9b65a0f78b09        13 days ago         86.1MB  
    kubeimage/kube-apiserver-amd64            v1.16.3             df60c7526a3d        13 days ago         217MB  
    k8s.gcr.io/kube-apiserver                 v1.16.3             df60c7526a3d        13 days ago         217MB  
    kubeimage/kube-controller-manager-amd64   v1.16.3             bb16442bcd94        13 days ago         163MB  
    k8s.gcr.io/kube-controller-manager        v1.16.3             bb16442bcd94        13 days ago         163MB  
    kubeimage/kube-scheduler-amd64            v1.16.3             98fecf43a54f        13 days ago         87.3MB  
    k8s.gcr.io/kube-scheduler                 v1.16.3             98fecf43a54f        13 days ago         87.3MB  
    coredns/coredns                           1.6.5               70f311871ae1        2 weeks ago         41.6MB  
    gcr.azk8s.cn/google_containers/etcd       3.3.15-0            b2756210eeab        2 months ago        247MB  
    k8s.gcr.io/etcd                           3.3.15-0            b2756210eeab        2 months ago        247MB  
    coredns/coredns                           1.6.2               bf261d157914        3 months ago        44.1MB  
    k8s.gcr.io/coredns                        1.6.2               bf261d157914        3 months ago        44.1MB  
    kubeimage/pause                           3.1                 da86e6ba6ca1        23 months ago       742kB  
    k8s.gcr.io/pause                          3.1                 da86e6ba6ca1        23 months ago       742kB  
    
    
  3. 获取默认pod的network范围

    chengf@chengf:~$ kubeadm config print init-defaults  
    apiVersion: kubeadm.k8s.io/v1beta2  
    bootstrapTokens:  
    - groups:  
      - system:bootstrappers:kubeadm:default-node-token  
      token: abcdef.0123456789abcdef  
      ttl: 24h0m0s  
      usages:  
      - signing  
      - authentication  
    kind: InitConfiguration  
    localAPIEndpoint:  
      advertiseAddress: 1.2.3.4  
      bindPort: 6443  
    nodeRegistration:  
      criSocket: /var/run/dockershim.sock  
      name: chengf  
      taints:  
      - effect: NoSchedule  
        key: node-role.kubernetes.io/master  
    ---  
    apiServer:  
      timeoutForControlPlane: 4m0s  
    apiVersion: kubeadm.k8s.io/v1beta2  
    certificatesDir: /etc/kubernetes/pki  
    clusterName: kubernetes  
    controllerManager: {}  
    dns:  
      type: CoreDNS  
    etcd:  
      local:  
        dataDir: /var/lib/etcd  
    imageRepository: k8s.gcr.io  
    kind: ClusterConfiguration  
    kubernetesVersion: v1.16.0  
    networking:  
      dnsDomain: cluster.local  
      serviceSubnet: 10.96.0.0/12  
    scheduler: {}  
    
    
  4. 通过kubeadm init安装master

    root@chengf:/etc/kubernetes# kubeadm init --kubernetes-version=v1.16.3 --pod-network-cidr=10.96.0.0/12 --apiserver-advertise-address=192.168.0.107 --node-name=chengf --ignore-preflight-errors=ImagePull  
    [init] Using Kubernetes version: v1.16.3  
    [preflight] Running pre-flight checks  
        [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/  
        [WARNING SystemVerification]: this Docker version is not on the list of validated versions: 19.03.5. Latest validated version: 18.09  
    [preflight] Pulling images required for setting up a Kubernetes cluster  
    [preflight] This might take a minute or two, depending on the speed of your internet connection  
    [preflight] You can also perform this action in beforehand using 'kubeadm config images pull'  
    [kubelet-start] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"  
    [kubelet-start] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"  
    [kubelet-start] Activating the kubelet service  
    [certs] Using certificateDir folder "/etc/kubernetes/pki"  
    [certs] Generating "ca" certificate and key  
    [certs] Generating "apiserver" certificate and key  
    [certs] apiserver serving cert is signed for DNS names [chengf kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.0.107]  
    [certs] Generating "apiserver-kubelet-client" certificate and key  
    [certs] Generating "front-proxy-ca" certificate and key  
    [certs] Generating "front-proxy-client" certificate and key  
    [certs] Generating "etcd/ca" certificate and key  
    [certs] Generating "etcd/server" certificate and key  
    [certs] etcd/server serving cert is signed for DNS names [chengf localhost] and IPs [192.168.0.107 127.0.0.1 ::1]  
    [certs] Generating "etcd/peer" certificate and key  
    [certs] etcd/peer serving cert is signed for DNS names [chengf localhost] and IPs [192.168.0.107 127.0.0.1 ::1]  
    [certs] Generating "etcd/healthcheck-client" certificate and key  
    [certs] Generating "apiserver-etcd-client" certificate and key  
    [certs] Generating "sa" key and public key  
    [kubeconfig] Using kubeconfig folder "/etc/kubernetes"  
    [kubeconfig] Writing "admin.conf" kubeconfig file  
    [kubeconfig] Writing "kubelet.conf" kubeconfig file  
    [kubeconfig] Writing "controller-manager.conf" kubeconfig file  
    [kubeconfig] Writing "scheduler.conf" kubeconfig file  
    [control-plane] Using manifest folder "/etc/kubernetes/manifests"  
    [control-plane] Creating static Pod manifest for "kube-apiserver"  
    [control-plane] Creating static Pod manifest for "kube-controller-manager"  
    [control-plane] Creating static Pod manifest for "kube-scheduler"  
    [etcd] Creating static Pod manifest for local etcd in "/etc/kubernetes/manifests"  
    [wait-control-plane] Waiting for the kubelet to boot up the control plane as static Pods from directory "/etc/kubernetes/manifests". This can take up to 4m0s  
    [apiclient] All control plane components are healthy after 17.505256 seconds  
    [upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace  
    [kubelet] Creating a ConfigMap "kubelet-config-1.16" in namespace kube-system with the configuration for the kubelets in the cluster  
    [upload-certs] Skipping phase. Please see --upload-certs  
    [mark-control-plane] Marking the node chengf as control-plane by adding the label "node-role.kubernetes.io/master=''"  
    [mark-control-plane] Marking the node chengf as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]  
    [bootstrap-token] Using token: 7zi6wy.j3mm4fzdyxc0m3bx  
    [bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles  
    [bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials  
    [bootstrap-token] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token  
    [bootstrap-token] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster  
    [bootstrap-token] Creating the "cluster-info" ConfigMap in the "kube-public" namespace  
    [addons] Applied essential addon: CoreDNS  
    [addons] Applied essential addon: kube-proxy  
      
    Your Kubernetes control-plane has initialized successfully!  
      
    To start using your cluster, you need to run the following as a regular user:  
      
      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 192.168.0.107:6443 --token 7zi6wy.j3mm4fzdyxc0m3bx \  
        --discovery-token-ca-cert-hash sha256:27e0d9fd7e5e309249cf3a515514e370c230b2115cea5170ec9e5be61c18b2c1  
    
    
    • kubernetes-version 版本号
    • pod-network-cidr 设置上一步骤中获取的IP范围
    • apiserver-advertise-address 设置成主机IP
    • node-name 主机名称
    • ignore-preflight-errors 忽略拉不到镜像的错误

    安装过程会有如下警告:

    [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
    [WARNING SystemVerification]: this Docker version is not on the list of validated versions: 19.03.5. Latest validated version: 18.09

  5. 按照输出,执行如下命令,使当前普通用户可以执行kubectl命令

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

安装node(在slave节点上执行)

  1. 安装kubelet kubeadm

    sudo apt install -y kubelet=1.16.3-00 kubeadm=1.16.3-00  
    sudo systemctl enable kubelet && systemctl start kubelet  
    
    
  2. 将从节点加入集群,执行主节点安装完成后生成的加入命令

    sudo kubeadm join 192.168.0.107:6443 --token 7zi6wy.j3mm4fzdyxc0m3bx --discovery-token-ca-cert-hash sha256:27e0d9fd7e5e309249cf3a515514e370c230b2115cea5170ec9e5be61c18b2c1  
    
    

如果加入过程出错了,可以在命令行后面加上 --5来看具体的错误信息
看到如下信息证明加入成功

```
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. 

```
  1. 在master节点上执行

    chengf@chengf:~$ kubectl get nodes 
    NAME     STATUS     ROLES    AGE     VERSION 
    chengf   NotReady   master   3d23h   v1.16.3 
    slave    NotReady   <none>   2m43s   v1.16.3 
    
    

    节点状态为NotReady,这是因为还没有安装CNI网络插件,现在安装下,具体CNI可参考
    CNI,本例选择weave

  2. 在主节点执行

    kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version| base64 | tr -d  '\n')" 
    
    

    如果执行出现如下错误,

    chengf@chengf:~$ kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version| base64 | tr -d  '\n')" 
    Unable to connect to the server: net/http: TLS handshake timeout 
    
    

    分成三步做

    1. 获取version

      chengf@chengf:~$ kubectl version | base64 | tr -d '\n'  
      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  
      
      
    2. 从浏览器执行

      https://cloud.weave.works/k8s/net?k8s-version=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  
      

      执行完会下载下来一个net.yaml,传到服务器上

    3. 执行

      chengf@chengf:~/soft$ kubectl apply -f net.yaml   
      serviceaccount/weave-net created  
      clusterrole.rbac.authorization.k8s.io/weave-net created  
      clusterrolebinding.rbac.authorization.k8s.io/weave-net created  
      role.rbac.authorization.k8s.io/weave-net created  
      rolebinding.rbac.authorization.k8s.io/weave-net created  
      daemonset.apps/weave-net created  
      
      
  3. 再次确认节点状态

    chengf@chengf:~/soft$ kubectl get nodes  
    NAME     STATUS     ROLES    AGE     VERSION  
    chengf   Ready      master   3d23h   v1.16.3  
    slave    NotReady   <none>   40m     v1.16.3  
     
    chengf@chengf:~/soft$ kubectl get pods --all-namespaces  
    NAMESPACE     NAME                             READY   STATUS              RESTARTS   AGE  
    kube-system   coredns-5644d7b6d9-gdjwp         1/1     Running             0          3d23h  
    kube-system   coredns-5644d7b6d9-s9l76         1/1     Running             0          3d23h  
    kube-system   etcd-chengf                      1/1     Running             0          3d23h  
    kube-system   kube-apiserver-chengf            1/1     Running             6          3d23h  
    kube-system   kube-controller-manager-chengf   1/1     Running             6          3d23h  
    kube-system   kube-proxy-g7f6j                 1/1     Running             0          3d23h  
    kube-system   kube-proxy-nljf6                 0/1     ContainerCreating   0          42m  
    kube-system   kube-scheduler-chengf            1/1     Running             7          3d23h  
    kube-system   weave-net-7zbps                  2/2     Running             0          7m31s  
    kube-system   weave-net-kt2rz                  0/2     ContainerCreating   0          7m31s  
    
    

    发现weave-net-kt2rz没有启动起来,查看原因

    kubectl --namespace=kube-system describe pod weave-net-kt2rz 
    
    
    Failed create pod sandbox: rpc error: code = Unknown desc = failed pulling image "k8s.gcr.io/pause:3.1": Error response from daemon: Get https://k8s.gcr.io/v2/: net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers) 
    
    

    是下不下来镜像k8s.gcr.io/pause:3.1,解决方法

    chengf@slave:~/soft$ docker pull kubeimage/pause:3.1 
    Pulling from kubeimage/pause  
    Image docker.io/kubeimage/pause:3.1 uses outdated schema1 manifest format. Please upgrade to a schema2 image for better future compatibility. More information at https://docs.docker.com/registry/spec/deprecated-schema-v1/  
    7675586df687: Pull complete   
    Digest: sha256:c780ae1f699e27c67bb6f1ac38f9b0a576a9d22c862aaae0d3549b6000569958  
    Status: Downloaded newer image for kubeimage/pause:3.1  
    docker.io/kubeimage/pause:3.1  
    chengf@slave:~/soft$ docker tag kubeimage/pause:3.1 k8s.gcr.io/pause:3.1  
    
    

    如果还有错误,可以一一排查,直到问题解决 ,最终结果

    chengf@chengf:~/soft$ kubectl get pods --all-namespaces  
    NAMESPACE     NAME                             READY   STATUS    RESTARTS   AGE  
    kube-system   coredns-5644d7b6d9-gdjwp         1/1     Running   0          3d23h  
    kube-system   coredns-5644d7b6d9-s9l76         1/1     Running   0          3d23h  
    kube-system   etcd-chengf                      1/1     Running   0          3d23h  
    kube-system   kube-apiserver-chengf            1/1     Running   6          3d23h  
    kube-system   kube-controller-manager-chengf   1/1     Running   6          3d23h  
    kube-system   kube-proxy-g7f6j                 1/1     Running   0          3d23h  
    kube-system   kube-proxy-nljf6                 1/1     Running   0          56m  
    kube-system   kube-scheduler-chengf            1/1     Running   7          3d23h  
    kube-system   weave-net-7zbps                  2/2     Running   0          21m  
    kube-system   weave-net-kt2rz                  2/2     Running   6          21m  
    
    

这样通过kubeadm工具就实现了kubernetes集群的搭建,如果集群安装失败,可以通过kubeadm reset命令恢复主机,之后再重新安装

posted @ 2020-02-11 20:06  高枫_henu  Views(294)  Comments(0Edit  收藏  举报