Kubernetes集羣的搭建方法其實有多種,好比我在以前的文章《利用K8S技術棧打造我的私有云(連載之:K8S集羣搭建)》中使用的就是二進制的安裝方法。雖然這種方法有利於咱們理解 k8s集羣,但卻過於繁瑣。而 kubeadm是 Kubernetes官方提供的用於快速部署Kubernetes集羣的工具,其歷經發展現在已經比較成熟了,利用其來部署 Kubernetes集羣能夠說是很是好上手,操做起來也簡便了許多,所以本文詳細敘述之。node
注: 本文首發於 My Personal Blog:CodeSheep·程序羊,歡迎光臨 小站linux
本文準備部署一個 一主兩從 的 三節點 Kubernetes集羣,總體節點規劃以下表所示:docker
主機名 | IP | 角色 |
---|---|---|
k8s-master | 192.168.39.79 | k8s主節點 |
k8s-node-1 | 192.168.39.77 | k8s從節點 |
k8s-node-2 | 192.168.39.78 | k8s從節點 |
下面介紹一下各個節點的軟件版本:shell
CentOS-7.4-64Bit
1.13.1
1.13.1
全部節點都須要安裝如下組件:json
Docker
:不用多說了吧kubelet
:運行於全部 Node上,負責啓動容器和 Podkubeadm
:負責初始化集羣kubectl
: k8s命令行工具,經過其能夠部署/管理應用 以及CRUD各類資源systemctl disable firewalld.service systemctl stop firewalld.service
setenforce 0 vi /etc/selinux/config SELINUX=disabled
swapoff -a
hostnamectl --static set-hostname k8s-master hostnamectl --static set-hostname k8s-node-1 hostnamectl --static set-hostname k8s-node-2
編輯 /etc/hosts
文件,加入如下內容:bootstrap
192.168.39.79 k8s-master 192.168.39.77 k8s-node-1 192.168.39.78 k8s-node-2
不贅述 ! ! !api
cat>>/etc/yum.repos.d/kubrenetes.repo<<EOF [kubernetes] name=Kubernetes Repo baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/ gpgcheck=0 gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg EOF
setenforce 0 sed -i 's/^SELINUX=enforcing$/SELINUX= disabled/' /etc/selinux/config yum install -y kubelet kubeadm kubectl systemctl enable kubelet && systemctl start kubelet
爲了應對網絡不順暢通的問題,咱們國內網絡環境只能提早手動下載相關鏡像並從新打 tag :瀏覽器
docker pull mirrorgooglecontainers/kube-apiserver:v1.13.1 docker pull mirrorgooglecontainers/kube-controller-manager:v1.13.1 docker pull mirrorgooglecontainers/kube-scheduler:v1.13.1 docker pull mirrorgooglecontainers/kube-proxy:v1.13.1 docker pull mirrorgooglecontainers/pause:3.1 docker pull mirrorgooglecontainers/etcd:3.2.24 docker pull coredns/coredns:1.2.6 docker pull registry.cn-shenzhen.aliyuncs.com/cp_m/flannel:v0.10.0-amd64 docker tag mirrorgooglecontainers/kube-apiserver:v1.13.1 k8s.gcr.io/kube-apiserver:v1.13.1 docker tag mirrorgooglecontainers/kube-controller-manager:v1.13.1 k8s.gcr.io/kube-controller-manager:v1.13.1 docker tag mirrorgooglecontainers/kube-scheduler:v1.13.1 k8s.gcr.io/kube-scheduler:v1.13.1 docker tag mirrorgooglecontainers/kube-proxy:v1.13.1 k8s.gcr.io/kube-proxy:v1.13.1 docker tag mirrorgooglecontainers/pause:3.1 k8s.gcr.io/pause:3.1 docker tag mirrorgooglecontainers/etcd:3.2.24 k8s.gcr.io/etcd:3.2.24 docker tag coredns/coredns:1.2.6 k8s.gcr.io/coredns:1.2.6 docker tag registry.cn-shenzhen.aliyuncs.com/cp_m/flannel:v0.10.0-amd64 quay.io/coreos/flannel:v0.10.0-amd64 docker rmi mirrorgooglecontainers/kube-apiserver:v1.13.1 docker rmi mirrorgooglecontainers/kube-controller-manager:v1.13.1 docker rmi mirrorgooglecontainers/kube-scheduler:v1.13.1 docker rmi mirrorgooglecontainers/kube-proxy:v1.13.1 docker rmi mirrorgooglecontainers/pause:3.1 docker rmi mirrorgooglecontainers/etcd:3.2.24 docker rmi coredns/coredns:1.2.6 docker rmi registry.cn-shenzhen.aliyuncs.com/cp_m/flannel:v0.10.0-amd64
而後再在 Master節點上執行以下命令初始化 k8s集羣:網絡
kubeadm init --kubernetes-version=v1.13.1 --apiserver-advertise-address 192.168.39.79 --pod-network-cidr=10.244.0.0/16
--kubernetes-version
: 用於指定 k8s版本--apiserver-advertise-address
:用於指定使用 Master的哪一個network interface進行通訊,若不指定,則 kubeadm會自動選擇具備默認網關的 interface--pod-network-cidr
:用於指定Pod的網絡範圍。該參數使用依賴於使用的網絡方案,本文將使用經典的flannel網絡方案。執行命令後,控制檯給出了以下所示的詳細集羣初始化過程:app
[root@localhost ~]# kubeadm init --config kubeadm-config.yaml W1224 11:01:25.408209 10137 strict.go:54] error unmarshaling configuration schema.GroupVersionKind{Group:"kubeadm.k8s.io", Version:"v1beta1", Kind:"ClusterConfiguration"}: error unmarshaling JSON: while decoding JSON: json: unknown field "\u00a0 podSubnet」 [init] Using Kubernetes version: v1.13.1 [preflight] Running pre-flight checks [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 "etcd/ca" certificate and key [certs] Generating "etcd/healthcheck-client" certificate and key [certs] Generating "etcd/server" certificate and key [certs] etcd/server serving cert is signed for DNS names [localhost.localdomain localhost] and IPs [192.168.39.79 127.0.0.1 ::1] [certs] Generating "etcd/peer" certificate and key [certs] etcd/peer serving cert is signed for DNS names [localhost.localdomain localhost] and IPs [192.168.39.79 127.0.0.1 ::1] [certs] Generating "apiserver-etcd-client" certificate and key [certs] Generating "ca" certificate and key [certs] Generating "apiserver-kubelet-client" certificate and key [certs] Generating "apiserver" certificate and key [certs] apiserver serving cert is signed for DNS names [localhost.localdomain kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.39.79] [certs] Generating "front-proxy-ca" certificate and key [certs] Generating "front-proxy-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 24.005638 seconds [uploadconfig] storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system」 Namespace [kubelet] Creating a ConfigMap "kubelet-config-1.13" in namespace kube-system with the configuration for the kubelets in the cluster [patchnode] Uploading the CRI Socket information "/var/run/dockershim.sock" to the Node API object "localhost.localdomain" as an annotation [mark-control-plane] Marking the node localhost.localdomain as control-plane by adding the label "node-role.kubernetes.io/master=''」 [mark-control-plane] Marking the node localhost.localdomain as control-plane by adding the taints [node-role.kubernetes.io/master:NoSchedule] [bootstrap-token] Using token: 26uprk.t7vpbwxojest0tvq [bootstrap-token] Configuring bootstrap tokens, cluster-info ConfigMap, RBAC Roles [bootstraptoken] configured RBAC rules to allow Node Bootstrap tokens to post CSRs in order for nodes to get long term certificate credentials [bootstraptoken] configured RBAC rules to allow the csrapprover controller automatically approve CSRs from a Node Bootstrap Token [bootstraptoken] configured RBAC rules to allow certificate rotation for all node client certificates in the cluster [bootstraptoken] creating the "cluster-info" ConfigMap in the "kube-public」 namespace [addons] Applied essential addon: CoreDNS [addons] Applied essential addon: kube-proxy Your Kubernetes master 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/ You can now join any number of machines by running the following on each node as root: kubeadm join 192.168.39.79:6443 --token 26uprk.t7vpbwxojest0tvq --discovery-token-ca-cert-hash sha256:028727c0c21f22dd29d119b080dcbebb37f5545e7da1968800140ffe225b0123 [root@localhost ~]#
在 Master上用 root用戶執行下列命令來配置 kubectl:
echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> /etc/profile source /etc/profile echo $KUBECONFIG
安裝 Pod網絡是 Pod之間進行通訊的必要條件,k8s支持衆多網絡方案,這裏咱們依然選用經典的 flannel方案
sysctl net.bridge.bridge-nf-call-iptables=1
kubectl apply -f kube-flannel.yaml
kube-flannel.yaml
文件在此
一旦 Pod網絡安裝完成,能夠執行以下命令檢查一下 CoreDNS Pod此刻是否正常運行起來了,一旦其正常運行起來,則能夠繼續後續步驟
kubectl get pods --all-namespaces -o wide
同時咱們能夠看到主節點已經就緒:kubectl get nodes
在兩個 Slave節點上分別執行以下命令來讓其加入Master上已經就緒了的 k8s集羣:
kubeadm join --token <token> <master-ip>:<master-port> --discovery-token-ca-cert-hash sha256:<hash>
若是 token忘記,則能夠去 Master上執行以下命令來獲取:
kubeadm token list
上述kubectl join命令的執行結果以下:
[root@localhost ~]# kubeadm join 192.168.39.79:6443 --token yndddp.oamgloerxuune80q --discovery-token-ca-cert-hash sha256:7a45c40b5302aba7d8b9cbd3afc6d25c6bb8536dd6317aebcd2909b0427677c8 [preflight] Running pre-flight checks [discovery] Trying to connect to API Server "192.168.39.79:6443」 [discovery] Created cluster-info discovery client, requesting info from "https://192.168.39.79:6443」 [discovery] Requesting info from "https://192.168.39.79:6443" again to validate TLS against the pinned public key [discovery] Cluster info signature and contents are valid and TLS certificate validates against pinned roots, will use API Server "192.168.39.79:6443」 [discovery] Successfully established connection with API Server "192.168.39.79:6443」 [join] Reading configuration from the cluster… [join] FYI: You can look at this config file with 'kubectl -n kube-system get cm kubeadm-config -oyaml’ [kubelet] Downloading configuration for the kubelet from the "kubelet-config-1.13" 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] Activating the kubelet service [tlsbootstrap] Waiting for the kubelet to perform the TLS Bootstrap… [patchnode] Uploading the CRI Socket information "/var/run/dockershim.sock" to the Node API object "localhost.localdomain" as an annotation 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 master to see this node join the cluster.
kubectl get nodes
kubectl get pods --all-namespaces -o wide
好了,集羣如今已經正常運行了,接下來看看如何正常的拆卸集羣。
首先處理各節點:
kubectl drain <node name> --delete-local-data --force --ignore-daemonsets kubectl delete node <node name>
一旦節點移除以後,則能夠執行以下命令來重置集羣:
kubeadm reset
就像給elasticsearch配一個可視化的管理工具同樣,咱們最好也給 k8s集羣配一個可視化的管理工具,便於管理集羣。
所以咱們接下來安裝 v1.10.0
版本的 kubernetes-dashboard,用於集羣可視化的管理。
docker pull registry.cn-qingdao.aliyuncs.com/wangxiaoke/kubernetes-dashboard-amd64:v1.10.0 docker tag registry.cn-qingdao.aliyuncs.com/wangxiaoke/kubernetes-dashboard-amd64:v1.10.0 k8s.gcr.io/kubernetes-dashboard-amd64:v1.10.0 docker image rm registry.cn-qingdao.aliyuncs.com/wangxiaoke/kubernetes-dashboard-amd64:v1.10.0
kubectl create -f dashboard.yaml
dashboard.yaml
文件在此
kubectl get pods --namespace=kube-system
[root@k8s-master ~]# kubectl get pods --namespace=kube-system NAME READY STATUS RESTARTS AGE coredns-86c58d9df4-4rds2 1/1 Running 0 81m coredns-86c58d9df4-rhtgq 1/1 Running 0 81m etcd-k8s-master 1/1 Running 0 80m kube-apiserver-k8s-master 1/1 Running 0 80m kube-controller-manager-k8s-master 1/1 Running 0 80m kube-flannel-ds-amd64-8qzpx 1/1 Running 0 78m kube-flannel-ds-amd64-jvp59 1/1 Running 0 77m kube-flannel-ds-amd64-wztbk 1/1 Running 0 78m kube-proxy-crr7k 1/1 Running 0 81m kube-proxy-gk5vf 1/1 Running 0 78m kube-proxy-ktr27 1/1 Running 0 77m kube-scheduler-k8s-master 1/1 Running 0 80m kubernetes-dashboard-79ff88449c-v2jnc 1/1 Running 0 21s
kubectl get service --namespace=kube-system
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP 5h38m kubernetes-dashboard NodePort 10.99.242.186 <none> 443:31234/TCP 14
openssl genrsa -des3 -passout pass:x -out dashboard.pass.key 2048 openssl rsa -passin pass:x -in dashboard.pass.key -out dashboard.key rm dashboard.pass.key openssl req -new -key dashboard.key -out dashboard.csr【如遇輸入,一路回車便可】
openssl x509 -req -sha256 -days 365 -in dashboard.csr -signkey dashboard.key -out dashboard.crt
dashboard.key
和 dashboard.crt
置於路徑 /home/share/certs
下,該路徑會配置到下面即將要操做的dashboard-user-role.yaml
文件中
kubectl create -f dashboard-user-role.yaml
dashboard-user-role.yaml
文件在此
kubectl describe secret/$(kubectl get secret -nkube-system |grep admin|awk '{print $1}') -nkube-system
[root@k8s-master ~]# kubectl describe secret/$(kubectl get secret -nkube-system |grep admin|awk '{print $1}') -nkube-system Name: admin-token-9d4vl Namespace: kube-system Labels: <none> Annotations: kubernetes.io/service-account.name: admin kubernetes.io/service-account.uid: a320b00f-07ed-11e9-93f2-000c2978f207 Type: kubernetes.io/service-account-token Data ==== ca.crt: 1025 bytes namespace: 11 bytes token: eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJhZG1pbi10b2tlbi05ZDR2bCIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50Lm5hbWUiOiJhZG1pbiIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VydmljZS1hY2NvdW50LnVpZCI6ImEzMjBiMDBmLTA3ZWQtMTFlOS05M2YyLTAwMGMyOTc4ZjIwNyIsInN1YiI6InN5c3RlbTpzZXJ2aWNlYWNjb3VudDprdWJlLXN5c3RlbTphZG1pbiJ9.WbaHx-BfZEd0SvJwA9V_vGUe8jPMUHjKlkT7MWJ4JcQldRFY8Tdpv5GKCY25JsvT_GM3ob303r0yE6vjQdKna7EfQNO_Wb2j1Yu5UvZnWw52HhNudHNOVL_fFRKxkSVjAILA_C_HvW6aw6TG5h7zHARgl71I0LpW1VESeHeThipQ-pkt-Dr1jWcpPgE39cwxSgi-5qY4ssbyYBc2aPYLsqJibmE-KUhwmyOheF4Lxpg7E3SQEczsig2HjXpNtJizCu0kPyiR4qbbsusulH-kdgjhmD9_XWP9k0BzgutXWteV8Iqe4-uuRGHZAxgutCvaL5qENv4OAlaArlZqSgkNWw
token既然生成成功,接下來就能夠打開瀏覽器,輸入 token來登陸進集羣管理頁面:
因爲能力有限,如有錯誤或者不當之處,還請你們批評指正,一塊兒學習交流!