Kubernetes安装——Ubuntu

基础环境

操作系统

$ cat /etc/issue                                                                                                                                                [22:34:09]
Ubuntu 16.04.6 LTS \n \l

cpu

$ lscpu                                                                                                                                                         [22:28:57]
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                2

内存

$ free -h                                                                                                                                                       [22:30:26]
              total        used        free      shared  buff/cache   available
Mem:           3.9G        293M        2.9G        4.0M        656M        3.3G
Swap:            0B          0B          0B

docker

$ sudo apt-get update
$ sudo apt-get install -y apt-transport-https ca-certificates curl gnupg-agent software-properties-common

安装

sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -                                                                             [22:37:06]
add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

安装docker

$ sudo apt-get update
$ sudo apt-get install -y docker-ce docker-ce-cli containerd.io

查看docker 版本

$ sudo docker version                                                                                                                                           [22:39:21]
Client: Docker Engine - Community
 Version:           19.03.12
 API version:       1.40
 Go version:        go1.13.10
 Git commit:        48a66213fe
 Built:             Mon Jun 22 15:45:49 2020
 OS/Arch:           linux/amd64
 Experimental:      false
Server: Docker Engine - Community
 Engine:
  Version:          19.03.12
  API version:      1.40 (minimum version 1.12)
  Go version:       go1.13.10
  Git commit:       48a66213fe
  Built:            Mon Jun 22 15:44:20 2020
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.2.13
  GitCommit:        7ad184331fa3e55e52b890ea95e65ba581ae3429
 runc:
  Version:          1.0.0-rc10
  GitCommit:        dc9208a3303feef5b3839f4323d9beb36df0a9dd
 docker-init:
  Version:          0.18.0
  GitCommit:        fec3683

关闭

$ sudo vi /etc/modules                                                                                                                                         
$ sudo vi /etc/sysctl.d/k8s.conf                                                                                                                                
$ sudo swapoff -a                                                                                                                                                   [22:44:44]
$ sudo sed -i 's/.*swap.*/#&/' /etc/fstab

切换

sudo su root
 # curl -s https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | apt-key add -
 #cat > /etc/apt/sources.list.d/aliyun-k8s.list <<EOF
deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main
EOF
 # apt update
 # apt install -y kubeadm kubelet kubectl ipvsadm ipset

安装

# kubeadm init --image-repository registry.aliyuncs.com/google_containers --pod-network-cidr=10.244.0.0/16
W1027 22:51:15.001922    5101 configset.go:348] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
[init] Using Kubernetes version: v1.19.3
[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/
[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'
[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 [izbp1dmodzug132aiko240z kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 10.111.118.193]
[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 [izbp1dmodzug132aiko240z localhost] and IPs [10.111.118.193 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [izbp1dmodzug132aiko240z localhost] and IPs [10.111.118.193 127.0.0.1 ::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
[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] Starting the kubelet
[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 18.502143 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.19" 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 izbp1dmodzug132aiko240z as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node izbp1dmodzug132aiko240z as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: o0runy.uikvs46vtfxidq0s
[bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles
[bootstrap-token] configured RBAC rules to allow Node Bootstrap tokens to get nodes
[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
[kubelet-finalize] Updating "/etc/kubernetes/kubelet.conf" to point to a rotatable kubelet client certificate and key
[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 10.111.118.193:6443 --token o0runy.uikvs46vtfxidq0s \
    --discovery-token-ca-cert-hash sha256:0fc36ea0a82cca6d155ef893f4646ecba10e67b355a54a9cfbca27fbea1a210b

配置文件

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

验证集群信息

# kubectl get nodes
NAME                      STATUS     ROLES    AGE     VERSION
izbp1dmodzug132aiko240z   NotReady   master   2m26s   v1.19.3
# kubectl get pod -n kube-system
NAME                                              READY   STATUS    RESTARTS   AGE
coredns-6d56c8448f-4krmb                          0/1     Pending   0          2m25s
coredns-6d56c8448f-9svcn                          0/1     Pending   0          2m25s
etcd-izbp1dmodzug132aiko240z                      1/1     Running   0          2m34s
kube-apiserver-izbp1dmodzug132aiko240z            1/1     Running   0          2m35s
kube-controller-manager-izbp1dmodzug132aiko240z   1/1     Running   0          2m35s
kube-proxy-hntxx                                  1/1     Running   0          2m25s
kube-scheduler-izbp1dmodzug132aiko240z            1/1     Running   0          2m35s

CoreDNS、kube-controller-manager 等依赖于网络的 Pod 都处于 Pending 状态，即调度失败。这当然是符合预期的：因为这个 Master 节点的网络尚未就绪。

flannel 网络插件安装

查看版本
https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: kube-flannel-ds
  namespace: kube-system
  labels:
    tier: node
    app: flannel
spec:
  selector:
    matchLabels:
      app: flannel
  template:
    metadata:
      labels:
        tier: node
        app: flannel
    spec:
      affinity:
        nodeAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
            nodeSelectorTerms:
            - matchExpressions:
              - key: kubernetes.io/os
                operator: In
                values:
                - linux
      hostNetwork: true
      priorityClassName: system-node-critical
      tolerations:
      - operator: Exists
        effect: NoSchedule
      serviceAccountName: flannel
      initContainers:
      - name: install-cni
        image: quay.io/coreos/flannel:v0.13.0

可能存在quay.io/coreos/flannel:v0.13.0 拉取失败的情况 可以使用 https://github.com/coreos/flannel/releases
的flanneld-v0.13.0-amd64.docker

执行解压命令

docker load <  flanneld-v0.13.0-amd64.docker

去除master

# kubectl get nodes
NAME                      STATUS   ROLES    AGE   VERSION
izbp1dmodzug132aiko240z   Ready    master   19m   v1.19.3
# kubectl taint nodes izbp1dmodzug132aiko240z node-role.kubernetes.io/master-

或者

$ kubectl taint nodes --all node-role.kubernetes.io/master-

在“node-role.kubernetes.io/master”这个键后面加上了一个短横线“-”，这个格式就意味着移除所有以“node-role.kubernetes.io/master”为键的 Taint。

Hello

kubectl create deployment nginx --image=nginx
kubectl expose deploy nginx --type=NodePort --port=8080 --target-port=80 --name=nginx-svc

pod

kubectl get pods
NAME                     READY   STATUS    RESTARTS   AGE
nginx-6799fc88d8-xnd4t   1/1     Running   0          28s

svc

# kubectl get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
nginx-svc    NodePort    10.111.49.102   <none>        8080:30232/TCP   82s

执行

# curl 10.111.49.102:8080
.....
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
....

问题

The connection to the server 127.0.0.1:32768 was refused - did you specify the right host or port?