使用Kubeadm在CentOS7.2上部署Kubernetes叢集
阿新 • • 發佈:2019-02-02
本文參考kubernetes官網文章Installing Kubernetes on Linux with kubeadm在CentOS7.2使用Kubeadm部署Kuebernetes叢集,解決了一些在按照該文件部署時遇到的問題。
作業系統版本
# cat /etc/redhat-release
CentOS Linux release 7.2.1511 (Core)
核心版本
# uname -r
3.10.0-327.el7.x86_64
叢集節點
192.168.120.122 kube-master 192.168.120.123 kube-agent1 192.168.120.124 kube-agent2 192.168.120.125 kube-agent3
即該叢集包含一個控制節點和三個工作節點。
部署前的準備
- 配置可以訪問google相關網站
這種部署方式使用的軟體包由google相關源提供,因此叢集節點必須能夠訪問外網,至於如何配置請自行解決。 - 關閉防火牆
# systemctl stop firewalld.service && systemctl disable firewalld.service
- 禁用SELinux
# setenforce 0
# sed -i.bak 's/SELINUX=enforcing/SELINUX=permissive/' /etc/selinux/config
- 配置yum源
# cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://packages.cloud.google.com/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF
安裝kubelet和kubeadm
在所有節點上安裝以下軟體包:
# yum install -y docker kubelet kubeadm kubectl kubernetes-cni
# systemctl enable docker && systemctl start docker
# systemctl enable kubelet && systemctl start kubelet
然後設定核心引數:
# sysctl net.bridge.bridge-nf-call-iptables=1
# sysctl net.bridge.bridge-nf-call-ip6tables=1
初始化控制節點
# kubeadm init --pod-network-cidr=10.244.0.0/16
因為在該叢集中將使用flannel搭建pod網路,因此必須新增–pod-network-cidr引數。
注意:初始化較慢,因為該過程會pull一些docker image。
該命令的輸出如下:
Initializing your master...
[kubeadm] WARNING: kubeadm is in beta, please do not use it for production clusters.
[init] Using Kubernetes version: v1.6.4
[init] Using Authorization mode: RBAC
[preflight] Running pre-flight checks
[certificates] Generated CA certificate and key.
[certificates] Generated API server certificate and key.
[certificates] API Server serving cert is signed for DNS names [kube-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.120.122]
[certificates] Generated API server kubelet client certificate and key.
[certificates] Generated service account token signing key and public key.
[certificates] Generated front-proxy CA certificate and key.
[certificates] Generated front-proxy client certificate and key.
[certificates] Valid certificates and keys now exist in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/admin.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/controller-manager.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/scheduler.conf"
[apiclient] Created API client, waiting for the control plane to become ready
[apiclient] All control plane components are healthy after 1377.560339 seconds
[apiclient] Waiting for at least one node to register
[apiclient] First node has registered after 6.039626 seconds
[token] Using token: 60bc68.e94800f3c5c4c2d5
[apiconfig] Created RBAC rules
[addons] Created essential addon: kube-proxy
[addons] Created essential addon: kube-dns
Your Kubernetes master has initialized successfully!
To start using your cluster, you need to run (as a regular user):
sudo cp /etc/kubernetes/admin.conf $HOME/
sudo chown $(id -u):$(id -g) $HOME/admin.conf
export KUBECONFIG=$HOME/admin.conf
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at: http://kubernetes.io/docs/admin/addons/
You can now join any number of machines by running the following on each node as root:
kubeadm join --token <token> 192.168.120.122:6443
觀察控制節點的docker image:
# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
gcr.io/google_containers/kube-apiserver-amd64 v1.6.4 4e3810a19a64 2 days ago 150.6 MB
gcr.io/google_containers/kube-controller-manager-amd64 v1.6.4 0ea16a85ac34 2 days ago 132.8 MB
gcr.io/google_containers/kube-proxy-amd64 v1.6.4 e073a55c288b 2 days ago 109.2 MB
gcr.io/google_containers/kube-scheduler-amd64 v1.6.4 1fab9be555e1 2 days ago 76.75 MB
gcr.io/google_containers/etcd-amd64 3.0.17 243830dae7dd 12 weeks ago 168.9 MB
gcr.io/google_containers/pause-amd64 3.0 99e59f495ffa 12 months ago 746.9 kB
按照初始化命令的提示執行以下操作:
# cp /etc/kubernetes/admin.conf $HOME/
# chown $(id -u):$(id -g) $HOME/admin.conf
# export KUBECONFIG=$HOME/admin.conf
隔離控制節點
# kubectl taint nodes --all node-role.kubernetes.io/master-
node "kube-master" tainted
安裝pod網路
# kubectl apply -f flannel/Documentation/kube-flannel-rbac.yml
clusterrole "flannel" created
clusterrolebinding "flannel" created
# kubectl apply -f flannel/Documentation/kube-flannel.yml
serviceaccount "flannel" created
configmap "kube-flannel-cfg" created
daemonset "kube-flannel-ds" created
可以通過git clone flannel倉庫:
# git clone https://github.com/coreos/flannel.git
新增工作節點
# kubeadm join --token <token> 192.168.120.122:6443
該操作輸出如下:
[kubeadm] WARNING: kubeadm is in beta, please do not use it for production clusters.
[preflight] Running pre-flight checks
[discovery] Trying to connect to API Server "192.168.120.122:6443"
[discovery] Created cluster-info discovery client, requesting info from "https://192.168.120.122:6443"
[discovery] Cluster info signature and contents are valid, will use API Server "https://192.168.120.122:6443"
[discovery] Successfully established connection with API Server "192.168.120.122:6443"
[bootstrap] Detected server version: v1.6.4
[bootstrap] The server supports the Certificates API (certificates.k8s.io/v1beta1)
[csr] Created API client to obtain unique certificate for this node, generating keys and certificate signing request
[csr] Received signed certificate from the API server, generating KubeConfig...
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
Node join complete:
* Certificate signing request sent to master and response
received.
* Kubelet informed of new secure connection details.
Run 'kubectl get nodes' on the master to see this machine join.
在控制節點觀察叢集狀態
# kubectl get nodes
NAME STATUS AGE VERSION
kube-agent1 Ready 16m v1.6.3
kube-agent2 Ready 16m v1.6.3
kube-agent3 Ready 16m v1.6.3
kube-master Ready 37m v1.6.3
# kubectl get pods --all-namespaces -o wide
NAMESPACE NAME READY STATUS RESTARTS AGE IP NODE
kube-system etcd-kube-master 1/1 Running 0 32m 192.168.120.122 kube-master
kube-system kube-apiserver-kube-master 1/1 Running 7 32m 192.168.120.122 kube-master
kube-system kube-controller-manager-kube-master 1/1 Running 0 32m 192.168.120.122 kube-master
kube-system kube-dns-3913472980-3x9wh 3/3 Running 0 37m 10.244.0.2 kube-master
kube-system kube-flannel-ds-1m4wz 2/2 Running 0 18m 192.168.120.122 kube-master
kube-system kube-flannel-ds-3jwf5 2/2 Running 0 17m 192.168.120.123 kube-agent1
kube-system kube-flannel-ds-41qbs 2/2 Running 4 17m 192.168.120.125 kube-agent3
kube-system kube-flannel-ds-ssjct 2/2 Running 4 17m 192.168.120.124 kube-agent2
kube-system kube-proxy-0mmfc 1/1 Running 0 17m 192.168.120.124 kube-agent2
kube-system kube-proxy-23vwr 1/1 Running 0 17m 192.168.120.125 kube-agent3
kube-system kube-proxy-5q8vq 1/1 Running 0 17m 192.168.120.123 kube-agent1
kube-system kube-proxy-8srwn 1/1 Running 0 37m 192.168.120.122 kube-master
kube-system kube-scheduler-kube-master 1/1 Running 0 32m 192.168.120.122 kube-master
至此,完成Kubernetes叢集的部署。