K8s在LinuxONE上搭建基於RHEL7 操做系統（一)

時間 2020-04-02

標籤 k8s linuxone 搭建基於 rhel7 rhel 系統欄目 Red Hat 简体版

原文原文鏈接

1、介紹

Kubernetes 是當前煊赫一時的技術,它已然成爲可開源界的PASS管理平臺的標準，當下文章對大多數是對X86平臺搭建Kubernetes平臺，下面筆者進行在LinuxONE上搭建開源的Kubernetes平臺。
搭建K8S 平臺主流的有兩種方法，node

第一種是基於二進制的搭建，經過一步一步的搭建能夠加深對K8S各個服務的理解。
官方推薦的自動化部署工具 kubeadm
本次使用官方推薦的Kubeadm 的搭建方法， kubedm 把K8S 自身的服務都被K8S自身的pod，除此以外事先的基礎服務是用system服務的方式運行。
master節點安裝組件：
docker、kubelet、kubeadm 基於本地的system服務運行
kube-proxy 是動態的可被k8s 管理的pod
api-server、kube-controller、etcd、是託guan在pod
node節點組件
docker、kubelet 基於本地的system服務運行
kube-proxy 是動態的可被k8s 管理的pod
flannel 是動態的可被k8s 管理的pod
2、安裝

1. 環境
安裝的環境可使用虛擬機也可使用Lpar，我這是使用的Openstack環境下面的虛擬機。虛擬機的規格爲4C10G50Glinux

系統版本	IP地址	主機名	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

環境準備工做git

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 <<EOF > /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

二、安裝docker包github

[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 <<EOF
 OPTIONS="daemon -s overlay"
 EOF
[root@rhel7-master docker-1.11.2-rhel7.2-20160623]#
啓動服務
systemctl daemon-reload
systemctl restart docker
[root@rhel7-master tmp]# docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
[root@rhel7-master tmp]#

三、安裝kubelet、kubeadm 等包
添加yum 源（master 和node 節點都要執行）docker

[root@rhel7-master ~]# cat > /etc/yum.repos.d/os.repo <<EOF
[k8s]
name=k8s
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-s390x/
gpgcheck=0
enabled=1
[clefos1]
name=cle1
baseurl=http://download.sinenomine.net/clefos/7.6/
gpgcheck=0
enabled=1
EOF
[root@rhel7-master ~]#

查看當前repo提供的包的版本bootstrap

yum list kubelet kubeadm kubectl  --showduplicates|sort -r

下面進行安裝1.174版本的包api

[root@rhel-master ~]# yum install kubeadm-1.17.4  kubelet-1.17.4 kubectl-1.17.4 -y
[root@rhel7-master ~]# systemctl enable --now kubelet

四、利用kubeadm 初始化環境
再此以前須要自行作好下面準備網絡

初始化環境(master 和node 節點都要執行)：
一、基於主機名通信
二、時間同步
三、防火牆關閉
四、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-iptablesapp

查看kubeadm 須要哪些基礎的docker imagetcp

[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

能夠看到咱們已經羅列出了須要的docker image ，因爲不可描述的因素，咱們沒法直接訪問k8s.gcr.io
因此須要咱們自行下載這幾個鏡像，我已經把鏡像上傳到了個人docker hub，你們能夠本身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

下載完後，咱們須要進行更改爲和咱們列出來同樣的名字，由於kubeadm 會去下載

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

除此以外，咱們還須要flannal的鏡像

docker pull erickshi/flannel:v0.12.0-s390x
docker tag erickshi/flannel:v0.12.0-s390x   k8s.gcr.io/flannel:v0.12.0-s390x

或者在百度雲盤下載，直接導入docker load 便可
連接:https://pan.baidu.com/s/1E5YLM8LhPvdo1mlSsNPVdg 密碼:vfis

進行環境的初始化

[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 ~]#

拷貝認證文件，而且查看當前pod和節點

[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 ~]#

安裝flannel

[root@rhel-master ~]# kubectl  apply -f https://github.com/coreos/flannel/blob/master/Documentation/kube-flannel.yml

再次查看網絡和節點

[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 ~]#

能夠看到節點已經成爲ready 狀態，而且kube-system 的pod 已經所有就緒。目前master節點的安裝搞一個段落，下面安裝node節點

安裝node節點
前置條件：
見環境準備工做
下面直接加入master節點

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節點

[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   <none>   8m7s    v1.17.4

因爲node-1節點的網絡沒有ready，下面看下pod狀態

[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   <none>           <none>
kube-system   coredns-6955765f44-sjsjs                        1/1     Running             0          9m14s   10.244.0.2      rhel-master.novalocal   <none>           <none>
kube-system   etcd-rhel-master.novalocal                      1/1     Running             0          9m31s   172.16.35.141   rhel-master.novalocal   <none>           <none>
kube-system   kube-apiserver-rhel-master.novalocal            1/1     Running             0          9m31s   172.16.35.141   rhel-master.novalocal   <none>           <none>
kube-system   kube-controller-manager-rhel-master.novalocal   1/1     Running             0          9m31s   172.16.35.141   rhel-master.novalocal   <none>           <none>
kube-system   kube-flannel-ds-s390x-ftz9h                     1/1     Running             0          8m19s   172.16.35.141   rhel-master.novalocal   <none>           <none>
kube-system   kube-flannel-ds-s390x-nl5q4                     0/1     Init:ErrImagePull   0          6m37s   172.16.35.138   rhel-node-1.novalocal   <none>           <none>
kube-system   kube-proxy-5vtcq                                1/1     Running             0          9m14s   172.16.35.141   rhel-master.novalocal   <none>           <none>
kube-system   kube-proxy-6qfc6                                1/1     Running             0          8m54s   172.16.35.138   rhel-node-1.novalocal   <none>           <none>
kube-system   kube-scheduler-rhel-master.novalocal            1/1     Running             0          9m31s   172.16.35.141   rhel-master.novalocal   <none>           <none>
[root@rhel-master ~]#

能夠看到下rhel-node-1的flannal pod 還沒有ready ，是由於 image 的問題，我手動導入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狀態

[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   <none>           <none>
kube-system   coredns-6955765f44-sjsjs                        1/1     Running   0          10m     10.244.0.2      rhel-master.novalocal   <none>           <none>
kube-system   etcd-rhel-master.novalocal                      1/1     Running   0          11m     172.16.35.141   rhel-master.novalocal   <none>           <none>
kube-system   kube-apiserver-rhel-master.novalocal            1/1     Running   0          11m     172.16.35.141   rhel-master.novalocal   <none>           <none>
kube-system   kube-controller-manager-rhel-master.novalocal   1/1     Running   0          11m     172.16.35.141   rhel-master.novalocal   <none>           <none>
kube-system   kube-flannel-ds-s390x-ftz9h                     1/1     Running   0          9m53s   172.16.35.141   rhel-master.novalocal   <none>           <none>
kube-system   kube-flannel-ds-s390x-nl5q4                     1/1     Running   0          8m11s   172.16.35.138   rhel-node-1.novalocal   <none>           <none>
kube-system   kube-proxy-5vtcq                                1/1     Running   0          10m     172.16.35.141   rhel-master.novalocal   <none>           <none>
kube-system   kube-proxy-6qfc6                                1/1     Running   0          10m     172.16.35.138   rhel-node-1.novalocal   <none>           <none>
kube-system   kube-scheduler-rhel-master.novalocal            1/1     Running   0          11m     172.16.35.141   rhel-master.novalocal   <none>           <none>
[root@rhel-master ~]#

k8s 的核心組件已經部署完成！