一、介绍

Kubernetes 是当先炙手可热的技术,它已然成为可开源界的PASS管理平台的标准，当下文章对大多数是对X86平台搭建Kubernetes平台，下面笔者进行在LinuxONE上搭建开源的Kubernetes平台。
搭建K8S 平台主流的有两种方法，

  1. 第一种是基于二进制的搭建，通过一步一步的搭建可以加深对K8S各个服务的理解。
  2. 官方推荐的自动化部署工具 kubeadm
    本次使用官方推荐的Kubeadm 的搭建方法， kubedm 把K8S 自身的服务都被K8S自身的pod，除此之外事先的基础服务是用system服务的方式运行。
    master节点安装组件：
    docker、kubelet、kubeadm 基于本地的system服务运行
    kube-proxy 是 动态的可被k8s 管理的pod
    api-server、kube-controller、etcd、 是托guan在pod
    node节点组件
    docker、kubelet 基于本地的system服务运行
    kube-proxy 是 动态的可被k8s 管理的pod
    flannel 是 动态的可被k8s 管理的pod

    二、安装

    1. 环境

系统版本 IP地址 主机名
ubuntu1~18.04.1 172.16.35.140 master
ubuntu1~18.04.1 woker-1

2.安装docker
安装基础的包

apt-get install \
    apt-transport-https \
    ca-certificates \
    curl \
    gnupg-agent \
    software-properties-common

添加官方的key

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

添加docker 源

sudo add-apt-repository \
 "deb [arch=s390x] https://download.docker.com/linux/ubuntu \
 $(lsb_release -cs) \
 stable"

安装docker

 apt-get update;apt-get install docker-ce

3、安装kubelet、kubeadm
添加源

apt-get update && apt-get install -y apt-transport-https
curl https://mirrors.aliyun.com/kubernetes/apt/doc/apt-key.gpg | apt-key add - 
cat </etc/apt/sources.list.d/kubernetes.list
deb https://mirrors.aliyun.com/kubernetes/apt/ kubernetes-xenial main
EOF  
apt-get update
apt-get install -y kubelet kubeadm kubec

4、利用kubeadm 初始化环境
再此之前需要自行做好下面准备

初始化环境：
1、基于主机名通讯
2、时间同步
3、防火墙关闭
4、swapoff -a && sysctl -w vm.swappiness=0 && sysctl -w net.ipv4.ip_forward=1 \
echo 1 > /proc/sys/net/bridge/bridge-nf-call-ip6tables \
echo 1 > /proc/sys/net/bridge/bridge-nf-call-iptables

查看kubeadm 需要哪些基础的docker image

root@master:/etc/apt# kubeadm config images list
W0321 08:51:12.828065   19587 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: dial tcp: lookup dl.k8s.io on 127.0.0.53:53: server misbehaving
W0321 08:51:12.828143   19587 version.go:102] falling back to the local client version: v1.17.4
W0321 08:51:12.828250   19587 validation.go:28] Cannot validate kube-proxy config - no validator is available
W0321 08:51:12.828275   19587 validation.go:28] Cannot validate kubelet config - no validator is available
k8s.gcr.io/kube-apiserver:v1.17.4
k8s.gcr.io/kube-controller-manager:v1.17.4
k8s.gcr.io/kube-scheduler:v1.17.4
k8s.gcr.io/kube-proxy:v1.17.4
k8s.gcr.io/pause:3.1
k8s.gcr.io/etcd:3.4.3-0
k8s.gcr.io/coredns:1.6.5

可以看到我们已经罗列出了需要的docker image ，由于不可描述的因素，我们无法直接访问k8s.gcr.io
所以需要我们自行下载这几个镜像，我已经把镜像上传到了我的docker hub， 大家可以自己pull

 docker pull  erickshi/kube-apiserver-s390x:v1.17.4
 docker pull  erickshi/kube-scheduler-s390x:v1.17.4
 docker pull  erickshi/kube-controller-manager-s390x:v1.17.4 
 docker pull  erickshi/pause-s390x:3.1 
 docker pull  erickshi/coredns:s390x-1.6.5
 docker pull  erickshi/etcd:3.4.3-0
 docker pull  erickshi/pause:3.1

下载完后，我们需要进行更改成和我们列出来一样的名字，因为kubeadm 会去下载

 docker tag erickshi/kube-apiserver-s390x:v1.17.4 k8s.gcr.io/kube-apiserver:v1.17.4
 docker tag erickshi/kube-scheduler-s390x:v1.17.4 k8s.gcr.io/kube-scheduler:v1.17.4
 docker tag erickshi/kube-controller-manager-s390x:v1.17.4 k8s.gcr.io/kube-controller-manager:v1.17.4
docker tag erickshi/pause-s390x:3.1 k8s.gcr.io/pause:3.1
docker tag erickshi/etcd-s390x:3.4.3-0 k8s.gcr.io/etcd:3.4.3-0
docker tags erickshi/coredns:s390x-1.6.5 k8s.gcr.io/coredns:1.6.5
docker tag erickshi/coredns:s390x-1.6.5 k8s.gcr.io/coredns:1.6.5

下面正式初始化集群

root@master:~#  kubeadm init --kubernetes-version=v1.17.4  --service-cidr=10.96.0.0/12
W0321 09:57:23.233367    9597 validation.go:28] Cannot validate kube-proxy config - no validator is available
W0321 09:57:23.233401    9597 validation.go:28] Cannot validate kubelet config - no validator is available
[init] Using Kubernetes version: v1.17.4
[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'
[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
[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 [master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 172.16.35.140]
[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 [master localhost] and IPs [172.16.35.140 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [master localhost] and IPs [172.16.35.140 127.0.0.1 ::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"
W0321 09:57:32.529825    9597 manifests.go:214] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[control-plane] Creating static Pod manifest for "kube-scheduler"
W0321 09:57:32.530693    9597 manifests.go:214] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[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 12.001699 seconds
[upload-config] Storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.17" 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 master as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node master as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: rp81u6.x7rky04rds2knxb8
[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
[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 172.16.35.140:6443 --token g6dykf.ac2mtjv9y4bfk4ve \
    --discovery-token-ca-cert-hash sha256:f868a8621420b253a7f6de4cae65c17c001c3ecb0740b549f9d0adca48b77f06

可以看到已经出初始化成功了，我们需要把用户的认证文件，拷贝到相应的位置

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

下面查看当前环境

root@master:/etc/apt# kubectl  get node
NAME     STATUS     ROLES    AGE    VERSION
master   NotReady   master   159m   v1.17.4
root@master:/etc/apt# kubectl  get cs
NAME                 STATUS    MESSAGE             ERROR
scheduler            Healthy   ok
controller-manager   Healthy   ok
etcd-0               Healthy   {"health":"true"}

下面我们查看托guan于k8s 的服务

root@master:/etc/apt# kubectl  get pod --all-namespaces
NAMESPACE     NAME                             READY   STATUS    RESTARTS   AGE
kube-system   coredns-6955765f44-gfjk2         0/1     Pending   0          159m
kube-system   coredns-6955765f44-l25vq         0/1     Pending   0          159m
kube-system   etcd-master                      1/1     Running   0          159m
kube-system   kube-apiserver-master            1/1     Running   0          159m
kube-system   kube-controller-manager-master   1/1     Running   0          159m
kube-system   kube-proxy-xfw6v                 1/1     Running   0          159m
kube-system   kube-scheduler-master            1/1     Running   0          159m

下面装flanal 网络
首先下载flannel image

wget https://github.com/coreos/flannel/releases/download/v0.12.0/flanneld-v0.12.0-s390x.docker
    docker load  < flanneld-v0.12.0-s390x.docker

  kubectl apply   -f https://raw.githubusercontent.com/coreos/flannel/2140ac876ef134e0ed5af15c65e414cf26827915/Documentation/kube-flannel.yml

查看当前的node

root@master:~# kubectl  get node
NAME     STATUS   ROLES    AGE     VERSION
master   Ready    master   2m31s   v1.17.4
root@master:~#
root@master:/tmp# kubectl  get pod --all-namespaces
NAMESPACE     NAME                             READY   STATUS    RESTARTS   AGE
kube-system   coredns-6955765f44-gzd5g         1/1     Running   0          99m
kube-system   coredns-6955765f44-qjzfd         1/1     Running   0          99m
kube-system   etcd-master                      1/1     Running   0          99m
kube-system   kube-apiserver-master            1/1     Running   0          99m
kube-system   kube-controller-manager-master   1/1     Running   0          99m
kube-system   kube-flannel-ds-s390x-mnqs5      1/1     Running   0          98m
kube-system   kube-proxy-jstmj                 1/1     Running   0          99m
kube-system   kube-scheduler-master            1/1     Running   0          99m

安装node节点

用kubeadm 加入master

root@node:~# kubeadm join 172.16.35.140:6443 --token g6dykf.ac2mtjv9y4bfk4ve     --discovery-token-ca-cert-hash sha256:f868a8621420b253a7f6de4cae65c17c001c3ecb0740b549f9d0adca48b77f06 -v=15
W0326 08:12:42.444748   10170 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set.
I0326 08:12:42.444787   10170 join.go:371] [preflight] found NodeName empty; using OS hostname as NodeName
I0326 08:12:42.444808   10170 initconfiguration.go:103] detected and using CRI socket: /var/run/dockershim.sock
[preflight] Running pre-flight checks
I0326 08:12:42.444861   10170 preflight.go:90] [preflight] Running general checks
I0326 08:12:42.444894   10170 checks.go:249] validating the existence and emptiness of directory /etc/kubernetes/manifests
I0326 08:12:42.444929   10170 checks.go:286] validating the existence of file /etc/kubernetes/kubelet.conf
.......
....:
........
{"machineID":"db770448baee44b4b07b748869a6f769","systemUUID":"db770448baee44b4b07b748869a6f769","bootID":"0112b3ec-f380-42d1-a5af-c459f7731c1d","kernelVersion":"4.15.0-91-generic","osImage":"Ubuntu 18.04.4 LTS","containerRuntimeVersion":"docker://18.6.3","kubeletVersion":"v1.17.4","kubeProxyVersion":"v1.17.4","operatingSystem":"linux","architecture":"s390x"}}}

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.

root@node:~#

在master节点查看当前状态

root@master:/tmp# kubectl  get node
NAME     STATUS     ROLES    AGE    VERSION
master   Ready      master   137m   v1.17.4
node     NotReady      10s    v1.17.4

当前node节点没有ready 是因为网络尚未安装，下面开始安装网络
node节点也需要flanneld、pause、kube-proxy镜像，此处略过导入步骤。

kubectl apply   -f https://raw.githubusercontent.com/coreos/flannel/2140ac876ef134e0ed5af15c65e414cf26827915/Documentation/kube-flannel.yml

再次查看node状态

root@master:~# kubectl  get node
NAME     STATUS   ROLES    AGE    VERSION
master   Ready    master   4h2m   v1.17.4
node     Ready       104m   v1.17.4

至此可以部署应用了！