目的
搭建一个单机环境学习实践用，既做Master节点也做Node节点，通过实际操作深入理解k8s中的基础概念
配置与运行Master
直接从模板机复制一台虚拟机作为本次单机环境的机器，参考Kuberneters入门 - 环境准备
初始化Master
通过命令行参数
- 宿主机可能无法访问虚拟机NAT地址，需要配置apiserver地址，用来从宿主机访问apiserver
- kubeadm默认会向服务器查询版本号，而查询接口很有可能无法访问，同时模板虚拟机中的版本是确定的，所以也指定了版本号
# 192.168.56.102需要改成你自己的虚拟机地址
$ sudo kubeadm init --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.56.102 --kubernetes-version=v1.11.1
[init] using Kubernetes version: v1.11.1
[preflight] running pre-flight checks
I0823 16:53:38.690945 15374 kernel_validator.go:81] Validating kernel version
I0823 16:53:38.691271 15374 kernel_validator.go:96] Validating kernel config
[WARNING SystemVerification]: docker version is greater than the most recently validated version. Docker version: 18.06.0-ce. Max validated version: 17.03
[preflight/images] Pulling images required for setting up a Kubernetes cluster
[preflight/images] This might take a minute or two, depending on the speed of your internet connection
[preflight/images] You can also perform this action in beforehand using 'kubeadm config images pull'
[kubelet] Writing kubelet environment file with flags to file "/var/lib/kubelet/kubeadm-flags.env"
[kubelet] Writing kubelet configuration to file "/var/lib/kubelet/config.yaml"
[preflight] Activating the kubelet service
[certificates] Generated ca certificate and key.
[certificates] Generated apiserver certificate and key.
[certificates] apiserver serving cert is signed for DNS names [k8s-master kubernetes kubernetes.default kubernetes.default.svc kubernetes.default.svc.cluster.local] and IPs [10.96.0.1 192.168.56.102]
[certificates] Generated apiserver-kubelet-client certificate and key.
[certificates] Generated sa key and public key.
[certificates] Generated front-proxy-ca certificate and key.
[certificates] Generated front-proxy-client certificate and key.
[certificates] Generated etcd/ca certificate and key.
[certificates] Generated etcd/server certificate and key.
[certificates] etcd/server serving cert is signed for DNS names [k8s-master localhost] and IPs [127.0.0.1 ::1]
[certificates] Generated etcd/peer certificate and key.
[certificates] etcd/peer serving cert is signed for DNS names [k8s-master localhost] and IPs [192.168.56.102 127.0.0.1 ::1]
[certificates] Generated etcd/healthcheck-client certificate and key.
[certificates] Generated apiserver-etcd-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"
[controlplane] wrote Static Pod manifest for component kube-apiserver to "/etc/kubernetes/manifests/kube-apiserver.yaml"
[controlplane] wrote Static Pod manifest for component kube-controller-manager to "/etc/kubernetes/manifests/kube-controller-manager.yaml"
[controlplane] wrote Static Pod manifest for component kube-scheduler to "/etc/kubernetes/manifests/kube-scheduler.yaml"
[etcd] Wrote Static Pod manifest for a local etcd instance to "/etc/kubernetes/manifests/etcd.yaml"
[init] waiting for the kubelet to boot up the control plane as Static Pods from directory "/etc/kubernetes/manifests"
[init] this might take a minute or longer if the control plane images have to be pulled
[apiclient] All control plane components are healthy after 47.013260 seconds
[uploadconfig] storing the configuration used in ConfigMap "kubeadm-config" in the "kube-system" Namespace
[kubelet] Creating a ConfigMap "kubelet-config-1.11" in namespace kube-system with the configuration for the kubelets in the cluster
[markmaster] Marking the node k8s-master as master by adding the label "node-role.kubernetes.io/master=''"
[markmaster] Marking the node k8s-master as master by adding the taints [node-role.kubernetes.io/master:NoSchedule]
[patchnode] Uploading the CRI Socket information "/var/run/dockershim.sock" to the Node API object "k8s-master" as an annotation
[bootstraptoken] using token: lkpkfd.ymx618h27m75aa56
[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 192.168.56.102:6443 --token lkpkfd.ymx618h27m75aa56 --discovery-token-ca-cert-hash sha256:ba896f324da35303f50e996c3b76f4dd6e428fc1381714e792f19f4fd38069b2
根据提示执行以下命令
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
通过配置文件
可以在配置文件中更改镜像源，这样就不会被墙了
参考Using kubeadm init with a configuration file
安装Pod网络插件
$ sudo sysctl net.bridge.bridge-nf-call-iptables=1
$ kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/v0.10.0/Documentation/kube-flannel.yml
clusterrole.rbac.authorization.k8s.io/flannel created
clusterrolebinding.rbac.authorization.k8s.io/flannel created
serviceaccount/flannel created
configmap/kube-flannel-cfg created
daemonset.extensions/kube-flannel-ds created
确认节点状态
确认Master节点已经处于Ready
$ kubectl get nodes
NAME STATUS ROLES AGE VERSION
k8s-master Ready master 4m v1.11.1
Master Isolation
默认情况下，Master节点不会被安排运行Pods，需要修改默认配置
$ kubectl taint nodes --all node-role.kubernetes.io/master-
node/k8s-master untainted
安装Dashboard
- 部署Dashboard
$ kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v1.8.3/src/deploy/alternative/kubernetes-dashboard.yaml
serviceaccount/kubernetes-dashboard created
role.rbac.authorization.k8s.io/kubernetes-dashboard-minimal created
rolebinding.rbac.authorization.k8s.io/kubernetes-dashboard-minimal created
deployment.apps/kubernetes-dashboard created
service/kubernetes-dashboard created
- 确认Pods状态
$ kubectl get pods --all-namespaces
NAMESPACE NAME READY STATUS RESTARTS AGE
kube-system coredns-78fcdf6894-2jswr 1/1 Running 0 14m
kube-system coredns-78fcdf6894-ftbzj 1/1 Running 0 14m
kube-system etcd-k8s-master 1/1 Running 0 14m
kube-system kube-apiserver-k8s-master 1/1 Running 0 13m
kube-system kube-controller-manager-k8s-master 1/1 Running 0 14m
kube-system kube-flannel-ds-lj5f5 1/1 Running 0 10m
kube-system kube-proxy-gbjbl 1/1 Running 0 14m
kube-system kube-scheduler-k8s-master 1/1 Running 0 13m
kube-system kubernetes-dashboard-6d4bc79449-g6klp 1/1 Running 0 6m
- 配置访问权限
编辑dashboard-admin.yaml
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
name: kubernetes-dashboard
labels:
k8s-app: kubernetes-dashboard
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: cluster-admin
subjects:
- kind: ServiceAccount
name: kubernetes-dashboard
namespace: kube-system
- 应用配置
$ kubectl create -f dashboard-admin.yaml
clusterrolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created
- 运行代理
$ kubectl proxy --address 0.0.0.0 --accept-hosts '.*'
Starting to serve on [::]:8001
服务地址如下，请将192.168.56.102改成你自己的地址
http://192.168.56.102:8001/api/v1/namespaces/kube-system/services/kubernetes-dashboard/proxy/#!/overview?namespace=default
- 在宿主机浏览器中访问dashboard
Dashboard预览
参考文档
Creating a single master cluster with kubeadm
kubeadm init
kubernetes安装dashboard，以及token认证问题
Official Dashboard Access control
