一、介绍
Kubernetes 是当前炙手可热的技术,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，
- 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。
- 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
安装的环境可以使用虚拟机也可以使用Lpar，我这是使用的Openstack环境下面的虚拟机。虚拟机的规格为4C10G50G
| 系统版本 | IP地址 | 主机名 | K8s version |
|---|---|---|---|
| Red Hat Enterprise Linux Server release 7.4 | 172.16.35.141 | rhel7-master | 1.17.4 |
| Red Hat Enterprise Linux Server release 7.4 | 172.16.35.138 | rhel7-node-1 | 1.17.4 |
环境准备工作
setenforce 0
sed -i 's/^SELINUX=enforcing$/SELINUX=permissive/' /etc/selinux/config
swapoff -a && sysctl -w vm.swappiness=0 && sysctl -w net.ipv4.ip_forward=1
cat < /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system
[root@rhel7-master ~]# yum install rng-tools -y
[root@rhel7-master ~]# systemctl enable rngd;systemctl start rngd 2、安装docker包
[root@rhel7-master tmp]# wget ftp://ftp.unicamp.br/pub/linuxpatch/s390x/redhat/rhel7.3/docker-17.05.0-ce-rhel7.3-20170523.tar.gz
[root@rhel7-master tmp]# tar -xvf docker-17.05.0-ce-rhel7.3-20170523.tar.gz
[root@rhel7-master tmp]#cd docker-17.05.0-ce-rhel7.3-20170523
[root@rhel7-master tmp]# cp docker* /usr/local/bin
[root@rhel7-master docker-1.11.2-rhel7.2-20160623]# cat > /etc/systemd/system/docker.service << EOF
[Unit]
Description=docker
[Service]
User=root
#ExecStart=/usr/bin/docker daemon -s overlay
ExecStart=/usr/local/bin/dockerd
EnvironmentFile=-/etc/sysconfig/docker
[Install]
WantedBy=multi-user.target
EOF
[root@rhel7-master docker-1.11.2-rhel7.2-20160623]# cat > /etc/sysconfig/docker <3、安装kubelet、kubeadm 等包
添加yum 源（master 和node 节点都要执行）
[root@rhel7-master ~]# cat > /etc/yum.repos.d/os.repo <查看 当前repo提供的包的版本
yum list kubelet kubeadm kubectl --showduplicates|sort -r下面进行安装1.174版本的包
[root@rhel-master ~]# yum install kubeadm-1.17.4 kubelet-1.17.4 kubectl-1.17.4 -y
[root@rhel7-master ~]# systemctl enable --now kubelet4、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(master 和node 节点都要执行)：
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@rhel7-master ~]# kubeadm config images list
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除此之外，我们还需要flannal的镜像
docker pull erickshi/flannel:v0.12.0-s390x
docker tag erickshi/flannel:v0.12.0-s390x k8s.gcr.io/flannel:v0.12.0-s390x或者在百度云盘下载，直接导入docker load 即可
链接:https://pan.baidu.com/s/1E5YLM8LhPvdo1mlSsNPVdg 密码:vfis
进行环境的初始化
[root@rhel-master ~]# kubeadm init --pod-network-cidr=10.244.0.0/16 --kubernetes-[root@rhel-master ~]# kubeadm init --pod-network-cidr=10.244.0.0/16
W0327 02:32:15.413161 6817 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 [::1]:53: read udp [::1]:32972->[::1]:53: read: connection refused
W0327 02:32:15.414720 6817 version.go:102] falling back to the local client version: v1.17.4
W0327 02:32:15.414805 6817 validation.go:28] Cannot validate kube-proxy config - no validator is available
W0327 02:32:15.414811 6817 validation.go:28] Cannot validate kubelet config - no validator is available
[init] Using Kubernetes version: v1.17.4
[preflight] Running pre-flight checks
[WARNING Firewalld]: firewalld is active, please ensure ports [6443 10250] are open or your cluster may not function correctly
[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: 17.05.0-ce. Latest validated version: 19.03
[WARNING Hostname]: hostname "rhel-master.novalocal" could not be reached
[WARNING Hostname]: hostname "rhel-master.novalocal": lookup rhel-master.novalocal on [::1]:53: read udp [::1]:33466->[::1]:53: read: connection refused
[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 [rhel-master.novalocal kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 172.16.35.141]
[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 [rhel-master.novalocal localhost] and IPs [172.16.35.141 127.0.0.1 ::1]
[certs] Generating "etcd/peer" certificate and key
[certs] etcd/peer serving cert is signed for DNS names [rhel-master.novalocal localhost] and IPs [172.16.35.141 127.0.0.1 ::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"
W0327 02:32:22.545271 6817 manifests.go:214] the default kube-apiserver authorization-mode is "Node,RBAC"; using "Node,RBAC"
[control-plane] Creating static Pod manifest for "kube-scheduler"
W0327 02:32:22.546219 6817 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 12.501743 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 rhel-master.novalocal as control-plane by adding the label "node-role.kubernetes.io/master=''"
[mark-control-plane] Marking the node rhel-master.novalocal as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[bootstrap-token] Using token: ckun8n.l8adw68yhpcsdmdu
[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 172.16.35.141:6443 --token ckun8n.l8adw68yhpcsdmdu \
--discovery-token-ca-cert-hash sha256:ea5a0282fa2582d6b10d4ea29a9b76318d1f023109248172e0820531ac1bef5e
[root@rhel-master ~]#拷贝认证文件，并且查看当前pod和节点
[root@rhel-master ~]# kubectl get node,pod --all-namespaces
NAME STATUS ROLES AGE VERSION
node/rhel-master.novalocal NotReady master 2m59s v1.17.4
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system pod/coredns-6955765f44-cbzss 0/1 Pending 0 2m41s
kube-system pod/coredns-6955765f44-dxjfb 0/1 Pending 0 2m41s
kube-system pod/etcd-rhel-master.novalocal 1/1 Running 0 2m56s
kube-system pod/kube-apiserver-rhel-master.novalocal 1/1 Running 0 2m56s
kube-system pod/kube-controller-manager-rhel-master.novalocal 1/1 Running 0 2m56s
kube-system pod/kube-proxy-6nmhq 1/1 Running 0 2m41s
kube-system pod/kube-scheduler-rhel-master.novalocal 1/1 Running 0 2m56s
[root@rhel-master ~]#安装flannel
[root@rhel-master ~]# kubectl apply -f https://github.com/coreos/flannel/blob/master/Documentation/kube-flannel.yml再次查看网络和节点
[root@rhel-master ~]# kubectl get node,pod --all-namespaces
NAME STATUS ROLES AGE VERSION
node/rhel-master.novalocal Ready master 9m21s v1.17.4
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system pod/coredns-6955765f44-cbzss 1/1 Running 0 9m3s
kube-system pod/coredns-6955765f44-dxjfb 1/1 Running 0 9m3s
kube-system pod/etcd-rhel-master.novalocal 1/1 Running 0 9m18s
kube-system pod/kube-apiserver-rhel-master.novalocal 1/1 Running 0 9m18s
kube-system pod/kube-controller-manager-rhel-master.novalocal 1/1 Running 0 9m18s
kube-system pod/kube-flannel-ds-s390x-zv6xl 1/1 Running 0 5m54s
kube-system pod/kube-proxy-6nmhq 1/1 Running 0 9m3s
kube-system pod/kube-scheduler-rhel-master.novalocal 1/1 Running 0 9m18s
[root@rhel-master ~]#可以看到节点已经成为ready 状态，并且kube-system 的pod 已经全部就绪。目前master节点的安装搞一个段落，下面安装node节点
安装node节点
前置条件：
见环境准备工作
下面直接 加入master节点
kubeadm join 172.16.35.141:6443 --token ckun8n.l8adw68yhpcsdmdu \
--discovery-token-ca-cert-hash sha256:ea5a0282fa2582d6b10d4ea29a9b76318d1f023109248172e0820531ac1bef5e
W0330 03:22:57.551161 2546 join.go:346] [preflight] WARNING: JoinControlPane.controlPlane settings will be ignored when control-plane flag is not set.
[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: 17.05.0-ce. Latest validated version: 19.03
[WARNING Hostname]: hostname "rhel-node-1.novalocal" could not be reached
[WARNING Hostname]: hostname "rhel-node-1.novalocal": lookup rhel-node-1.novalocal on [::1]:53: read udp [::1]:48786->[::1]:53: read: connection refused
[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-1.17" 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.
[root@rhel-node-1 ~]#下面再次查看node节点
[root@rhel-master ~]# kubectl get node
NAME STATUS ROLES AGE VERSION
rhel-master.novalocal Ready master 8m47s v1.17.4
rhel-node-1.novalocal NotReady 8m7s v1.17.4 由于node-1节点的网络没有ready，下面看下pod状态
[root@rhel-master ~]# kubectl get pod --all-namespaces -owide
NAMESPACE NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
kube-system coredns-6955765f44-9j5mc 1/1 Running 0 9m14s 10.244.0.3 rhel-master.novalocal
kube-system coredns-6955765f44-sjsjs 1/1 Running 0 9m14s 10.244.0.2 rhel-master.novalocal
kube-system etcd-rhel-master.novalocal 1/1 Running 0 9m31s 172.16.35.141 rhel-master.novalocal
kube-system kube-apiserver-rhel-master.novalocal 1/1 Running 0 9m31s 172.16.35.141 rhel-master.novalocal
kube-system kube-controller-manager-rhel-master.novalocal 1/1 Running 0 9m31s 172.16.35.141 rhel-master.novalocal
kube-system kube-flannel-ds-s390x-ftz9h 1/1 Running 0 8m19s 172.16.35.141 rhel-master.novalocal
kube-system kube-flannel-ds-s390x-nl5q4 0/1 Init:ErrImagePull 0 6m37s 172.16.35.138 rhel-node-1.novalocal
kube-system kube-proxy-5vtcq 1/1 Running 0 9m14s 172.16.35.141 rhel-master.novalocal
kube-system kube-proxy-6qfc6 1/1 Running 0 8m54s 172.16.35.138 rhel-node-1.novalocal
kube-system kube-scheduler-rhel-master.novalocal 1/1 Running 0 9m31s 172.16.35.141 rhel-master.novalocal
[root@rhel-master ~]# 可以看到下rhel-node-1的flannal pod 尚未ready ，是因为 image 的问题，我手动导入image
[root@rhel-node-1 ~]# docker load < flannelv0.12.0-s390x.tar
1f106b41b4d6: Loading layer 5.916MB/5.916MB
271ca11ef489: Loading layer 3.651MB/3.651MB
fbd88a276dca: Loading layer 10.77MB/10.77MB
3b7ae8a9c323: Loading layer 2.332MB/2.332MB
4c4bfa1b47e6: Loading layer 35.23MB/35.23MB
b67de7789e55: Loading layer 5.12kB/5.12kB
Loaded image: quay.io/coreos/flannel:v0.12.0-s390x
[root@rhel-node-1 ~]#再次查看pod状态
[root@rhel-master ~]# kubectl get pod --all-namespaces -owide
NAMESPACE NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
kube-system coredns-6955765f44-9j5mc 1/1 Running 0 10m 10.244.0.3 rhel-master.novalocal
kube-system coredns-6955765f44-sjsjs 1/1 Running 0 10m 10.244.0.2 rhel-master.novalocal
kube-system etcd-rhel-master.novalocal 1/1 Running 0 11m 172.16.35.141 rhel-master.novalocal
kube-system kube-apiserver-rhel-master.novalocal 1/1 Running 0 11m 172.16.35.141 rhel-master.novalocal
kube-system kube-controller-manager-rhel-master.novalocal 1/1 Running 0 11m 172.16.35.141 rhel-master.novalocal
kube-system kube-flannel-ds-s390x-ftz9h 1/1 Running 0 9m53s 172.16.35.141 rhel-master.novalocal
kube-system kube-flannel-ds-s390x-nl5q4 1/1 Running 0 8m11s 172.16.35.138 rhel-node-1.novalocal
kube-system kube-proxy-5vtcq 1/1 Running 0 10m 172.16.35.141 rhel-master.novalocal
kube-system kube-proxy-6qfc6 1/1 Running 0 10m 172.16.35.138 rhel-node-1.novalocal
kube-system kube-scheduler-rhel-master.novalocal 1/1 Running 0 11m 172.16.35.141 rhel-master.novalocal
[root@rhel-master ~]# k8s 的核心组件已经部署完成！