K8S搭建-1 Master 2 Workers（dashboard+ingress）

本文讲述k8s最新版的搭建（v1.15.2）

分如下几个topic步骤：

各个节点的基本配置
master节点的构建
worker节点的构建
安装dashboard
安装ingress
常见命令
docker镜像惹的祸

各个节点的基本配置（以下命令每个节点都要执行：Master, Work1, Work2）

IP自己变化下，根据实际情况

systemctl stop firewalld && systemctl disable firewalld

cat >>/etc/hosts<<EOF
10.8.1.1 k8s-master1  api.k8s.cn
10.8.1.2 k8s-slave1
10.8.1.3 k8s-slave2
EOF

# 新建 iptable 配置修改文件
cat <<EOF >  net.iptables.k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF

#关闭 swap 分区
sudo swapoff -a

#防止开机自动挂载 swap 分区，注释掉配置
sudo sed -i '/ swap / s/^(.*)$/#1/g' /etc/fstab

#关闭 SELinux
sudo setenforce 0

#防止开机启动开启，修改 SELINUX 配置
sudo sed -i s'/SELINUX=enforcing/SELINUX=disabled'/g /etc/selinux/config

配置 iptables
sudo mv net.iptables.k8s.conf /etc/sysctl.d/ && sudo sysctl --system

#yum增加阿里云针对kubernetes镜像
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

yum update

#安装 wget 
sudo yum install -y wget

#安装docker
yum install docker.x86_64 -y

#安装k8s工具
yum install -y kubelet kubeadm kubectl

#重启服务
systemctl enable kubelet && systemctl start kubelet

然后需要准备docker images（任然需要在master, worker1, worker2节点上分别执行）

vi init-docker-images.sh

#然后内容如下
docker pull registry.aliyuncs.com/google_containers/kube-apiserver:v1.15.2
docker pull registry.aliyuncs.com/google_containers/kube-controller-manager:v1.15.2
docker pull registry.aliyuncs.com/google_containers/coredns:1.3.1
docker pull registry.aliyuncs.com/google_containers/kube-proxy:v1.15.2
docker pull registry.aliyuncs.com/google_containers/kube-scheduler:v1.15.2
docker pull registry.aliyuncs.com/google_containers/etcd:3.2.24
docker pull registry.aliyuncs.com/google_containers/etcd:3.3.10
docker pull registry.aliyuncs.com/google_containers/pause:3.1
docker pull registry.aliyuncs.com/google_containers/kubernetes-dashboard-amd64:v1.10.0
docker pull registry.aliyuncs.com/google_containers/kubernetes-dashboard-amd64:v1.10.1
docker pull docker.io/jmgao1983/flannel:v0.11.0-amd64
docker pull quay-mirror.qiniu.com/kubernetes-ingress-controller/nginx-ingress-controller:0.25.0

docker tag registry.aliyuncs.com/google_containers/kube-apiserver:v1.15.2 k8s.gcr.io/kube-apiserver:v1.15.2
docker tag registry.aliyuncs.com/google_containers/kube-controller-manager:v1.15.2 k8s.gcr.io/kube-controller-manager:v1.15.2
docker tag registry.aliyuncs.com/google_containers/coredns:1.3.1 k8s.gcr.io/coredns:1.3.1
docker tag registry.aliyuncs.com/google_containers/kube-proxy:v1.15.2 k8s.gcr.io/kube-proxy:v1.15.2
docker tag registry.aliyuncs.com/google_containers/kube-scheduler:v1.15.2 k8s.gcr.io/kube-scheduler:v1.15.2
docker tag registry.aliyuncs.com/google_containers/etcd:3.3.10 k8s.gcr.io/etcd:3.3.10
docker tag registry.aliyuncs.com/google_containers/coredns:1.3.1 k8s.gcr.io/coredns:1.3.1
docker tag registry.aliyuncs.com/google_containers/pause:3.1 k8s.gcr.io/pause:3.1
docker tag registry.aliyuncs.com/google_containers/kubernetes-dashboard-amd64:v1.10.0 k8s.gcr.io/kubernetes-dashboard-amd64:v1.10.0
docker tag registry.aliyuncs.com/google_containers/kubernetes-dashboard-amd64:v1.10.1 k8s.gcr.io/kubernetes-dashboard-amd64:v1.10.1
docker tag docker.io/jmgao1983/flannel:v0.11.0-amd64 quay.io/coreos/flannel:v0.11.0-amd64
docker tag quay-mirror.qiniu.com/kubernetes-ingress-controller/nginx-ingress-controller:0.25.0 quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.25.0

执行直到下载完成：

./init-docker-images.sh

master节点的构建

kubeadm init --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=0.0.0.0  --kubernetes-version=v1.15.2

然后记录下类似如下的string：

kubeadm join api.k8s.cn:6443 --token b5jxzg.5jtj2odzoqujikk1 
    --discovery-token-ca-cert-hash sha256:90d0ad57b39bf47bface0c7f4edec480aaf8352cab872f4d52072f998cf45105

此时，k8s集群会处于NotReady状态（Master节点，用如下命令查看kubectl get nodes），需要如下：

mkdir -p $HOME/.kube

sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config

sudo chown $(id -u):$(id -g) $HOME/.kube/config


vi /var/lib/kubelet/kubeadm-flags.env

#然后把--network-plugin=cni 这些文本删除
#保存后重启k8s服务


service kubelet restart

稍等片刻，master节点就会变成Ready状态(kubectl get nodes)

worker节点的构建（worker1和worker2节点分别执行）

kubeadm join {master1的ip，需自行替换}:6443 --token rntn5f.vy9h28s4pxwx6eig 
    --discovery-token-ca-cert-hash sha256:62624adcc8aa5baa095dae607b8e57c8b619db956ad69e0e97f0e40c74542a92

vi /var/lib/kubelet/kubeadm-flags.env

#然后把--network-plugin=cni 这些文本删除
#保存后重启k8s服务


service kubelet restart

安装dashboard（只要在master节点操作）

wget https://raw.githubusercontent.com/kubernetes/dashboard/v1.10.1/src/deploy/recommended/kubernetes-dashboard.yaml


vi kubernetes-dashboard.yaml
#开始修改NodePort，在文件的最后

# ------------------- Dashboard Service ------------------- #

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
spec:
  type: NodePort
  ports:
    - port: 443
      targetPort: 8443
      nodePort: 30001
  selector:
    k8s-app: kubernetes-dashboard

kubectl apply -f kubernetes-dashboard.yaml

新建账号

vi dashboard-account.yaml

#内容如下
apiVersion: v1
kind: ServiceAccount
metadata:
  name: aks-dashboard-admin
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: aks-dashboard-admin
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: aks-dashboard-admin
  namespace: kube-system
---
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
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: kubernetes-dashboard-head
  labels:
    k8s-app: kubernetes-dashboard-head
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: kubernetes-dashboard-head
  namespace: kube-system


#执行
kubectl apply -f dashboard-account.yaml

　　然后就能用firefox访问https://master的ip地址:30001

接下来找出token：

[root@k8s-master1 ~]# kubectl -n kube-system get secrets|grep aks-dashboard-admin
aks-dashboard-admin-token-gmjfv                  kubernetes.io/service-account-token   3      4h52m


[root@k8s-master1 ~]# kubectl -n kube-system describe secret aks-dashboard-admin-token-gmjfv
Name:         aks-dashboard-admin-token-gmjfv
Namespace:    kube-system
Labels:       <none>
Annotations:  kubernetes.io/service-account.name: aks-dashboard-admin
              kubernetes.io/service-account.uid: 87d4ec1b-1829-4420-98d6-e77c1519aed6

Type:  kubernetes.io/service-account-token

Data
====
ca.crt:     1025 bytes
namespace:  11 bytes
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6IiJ9.eyJpc3MiOiJrdWJlcm5ldGVzL3NlcnZpY2VhY2NvdW50Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9uYW1lc3BhY2UiOiJrdWJlLXN5c3RlbSIsImt1YmVybmV0ZXMuaW8vc2VydmljZWFjY291bnQvc2VjcmV0Lm5hbWUiOiJha3MtZGFzaGJvYXJkLWFkbWluLXRva2VuLWdtamZ2Iiwia3ViZXJuZXRlcy5pby9zZXJ2aWNlYWNjb3VudC9zZXJ2aWNlLWFjY291bnQubmFtZSI6ImFrcy1kYXNoYm9hcmQtYWRtaW4iLCJrdWJlcm5ldGVzLmlvL3NlcnZpY2VhY2NvdW50L3NlcnZpY2UtYWNjb3VudC51aWQiOiI4N2Q0ZWMxYi0xODI5LTQ0MjAtOThkNi1lNzdjMTUxOWFlZDYiLCJzdWIiOiJzeXN0ZW06c2VydmljZWFjY291bnQ6a3ViZS1zeXN0ZW06YWtzLWRhc2hib2FyZC1hZG1pbiJ9.ELpsYbmWhW1sr3DOZfyupOkb87AbJ7sVoXEBitoTD46kuuNYcn8ajvwJcdfGruwrM9LwDcvMN7jD5UFF7-rgz1MUBEOZCoAjXFRrM1-Jn59TlXMk9W9JRD3DhMtuBRh6XUgPRjf755qr7WzR_DC8aCwjywAvFE1_R4N2oMZIU8gdmG0BsqwACHIbBnLJDAElBvgnKl8Jm4_XzKZW5ls-C45PSu-GC-yszt8qSN2bO5Z_rIUXhvK13Es5d0nUBvcanFBOsLjotWry195SWKEAuLiMp7qm6RJRrYWEpObh81w3MvbtrycZGMP7g-9H3s5vmHgs7HAnvjTEQht4c0F5qA
[root@k8s-master1 ~]#

用上面这个token登录就行了　

安装ingress

kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/static/mandatory.yaml

#新建ingress-service,NodePort类型
#ingress-service.yaml

apiVersion: v1
kind: Service
metadata:
  name: ingress-nginx
  namespace: ingress-nginx
spec:
  type: NodePort
  ports:
  - name: http
    port: 80
    targetPort: 80
    protocol: TCP
    nodePort: 30080
  - name: https
    port: 443
    targetPort: 443
    protocol: TCP
    nodePort: 30443
  selector:
     "app.kubernetes.io/name": "ingress-nginx",
     "app.kubernetes.io/part-of": "ingress-nginx"


kubectl apply -f ingress-service.yaml

需要在k8s外部部署1个nginx slb，把所有流量都转发到worker节点的上述端口-30080，proxy_pass ip为worker节点的2个ip地址

如果CoreDNS运转不正常，则需要删除重装CoreDNS组件

kubectl delete deploy coredns -n kube-system



vim coredns-ha.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    k8s-app: kube-dns
  name: coredns
  namespace: kube-system
spec:
  #集群规模可自行配置
  replicas: 2
  selector:
    matchLabels:
      k8s-app: kube-dns
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 1
    type: RollingUpdate
  template:
    metadata:
      labels:
        k8s-app: kube-dns
    spec:
      affinity:
        podAntiAffinity:
          preferredDuringSchedulingIgnoredDuringExecution:
          - weight: 100
            podAffinityTerm:
              labelSelector:
                matchExpressions:
                - key: k8s-app
                  operator: In
                  values:
                  - kube-dns
              topologyKey: kubernetes.io/hostname
      containers:
      - args:
        - -conf
        - /etc/coredns/Corefile
        image: registry.cn-hangzhou.aliyuncs.com/google_containers/coredns:1.2.6
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 5
          httpGet:
            path: /health
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 60
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 5
        name: coredns
        ports:
        - containerPort: 53
          name: dns
          protocol: UDP
        - containerPort: 53
          name: dns-tcp
          protocol: TCP
        - containerPort: 9153
          name: metrics
          protocol: TCP
        resources:
          limits:
            memory: 170Mi
          requests:
            cpu: 100m
            memory: 70Mi
        securityContext:
          allowPrivilegeEscalation: false
          capabilities:
            add:
            - NET_BIND_SERVICE
            drop:
            - all
          readOnlyRootFilesystem: true
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
        volumeMounts:
        - mountPath: /etc/coredns
          name: config-volume
          readOnly: true
      dnsPolicy: Default
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      serviceAccount: coredns
      serviceAccountName: coredns
      terminationGracePeriodSeconds: 30
      tolerations:
      - key: CriticalAddonsOnly
        operator: Exists
      - effect: NoSchedule
        key: node-role.kubernetes.io/master
      volumes:
      - configMap:
          defaultMode: 420
          items:
          - key: Corefile
            path: Corefile
          name: coredns
        name: config-volume




kubectl apply -f coredns-ha.yaml

flannel部署

wget https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

kubectl apply -f kube-flannel.yml

需要先下载下来yaml，然后修改里面的子网配置，最好reboot　　

常见命令

#当join或者初始化k8s集群失败时，执行
kubeadm reset

#查看集群所有节点
kubectl get nodes


#查看secrets
kubectl get secrets
kubectl -n kube-system get secrets

#查看具体pod明细，比如非Running状态下想看原因
kubectl describe pod {pod名称}
kubectl -n kube-system describe pod {pod名称}

#查看docker容器监控信息
docker stats -a

#查看token列表
kubeadm token list

#查看证书hash
openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | openssl dgst -sha256 -hex | sed 's/^.* //'

docker镜像惹的祸

由于有些docker镜像被墙了，因此默认安装时会阻塞住，解决方法是提前下载，配合国内镜像下载

如果是国内镜像下载的，namespace就会发生改变，因此下载完成后，需要docker tag命令重新tag到国外namespace

不足点，后续解决：

master节点的高可用
etcd的高可用（其实包含在上面的）
journalctl -f -u kubelet.service
https://blog.csdn.net/wangmiaoyan/article/details/101216496