kubernetes集群：向pod里的/etc/hosts添加解析

K8S向pod里的/etc/hosts添加解析

之前我们已经搭建了git,nexus,nacos,jenkins。域名都是临时添加的，非正式域名。所以pod没法解析这些地址。如图：

解决办法

利用hostAliases添加你需要的解析，如图：

验证

k8s集群搭建jenkins的配置文件

# cat jenkins-rbac.yaml 
apiVersion: v1
kind: ServiceAccount
metadata:
  name: jenkins
  namespace: kube-ops

---

kind: Role
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: jenkins
  namespace: kube-ops
rules:
  - apiGroups: [""]
    resources: ["pods"]
    verbs: ["create","delete","get","list","patch","update","watch"]
  - apiGroups: [""]
    resources: ["pods/exec"]
    verbs: ["create","delete","get","list","patch","update","watch"]
  - apiGroups: [""]
    resources: ["pods/log"]
    verbs: ["get","list","watch"]
  - apiGroups: [""]
    resources: ["secrets"]
    verbs: ["get"]

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: RoleBinding
metadata:
  name: jenkins
  namespace: kube-ops
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: jenkins
subjects:
  - kind: ServiceAccount
    name: jenkins
    namespace: kube-ops

=====

# cat jenkins-pvc.yaml 
apiVersion: v1
kind: PersistentVolume
metadata:
  name: opspv
spec:
  capacity:
    storage: 50Gi
  accessModes:
  - ReadWriteMany
  persistentVolumeReclaimPolicy: Delete
  nfs:
    server: 10.10.4.85
    path: /data/jenkins

---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: opspvc
  namespace: kube-ops
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 50Gi

===

# cat jenkins-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: jenkins
  namespace: kube-ops
spec:
  selector:
    matchLabels:
      app: jenkins
  template:
    metadata:
      labels:
        app: jenkins
    spec:
      hostAliases:
      - ip: "10.10.4.86"
        hostnames:
        - "jenkins.vonedao.com"
        - "gitlab.vonedao.com"
        - "nacos.vonedao.com"
        - "docker.vonedao.com"
        - "nexus.vonedao.com"
      terminationGracePeriodSeconds: 10
      serviceAccountName: jenkins
      containers:
      - name: jenkins
        image: jenkins/jenkins:lts
        imagePullPolicy: IfNotPresent
        ports:
        - containerPort: 8080
          name: web
          protocol: TCP
        - containerPort: 50000
          name: agent
          protocol: TCP
        resources:
          limits:
            cpu: 2000m
            memory: 4Gi
          requests:
            cpu: 1000m
            memory: 2Gi
        livenessProbe:
          httpGet:
            path: /login
            port: 8080
          initialDelaySeconds: 60
          timeoutSeconds: 5
          failureThreshold: 12
        readinessProbe:
          httpGet:
            path: /login
            port: 8080
          initialDelaySeconds: 60
          timeoutSeconds: 5
          failureThreshold: 12
        volumeMounts:
        - name: jenkinshome
          #subPath: jenkins
          mountPath: /var/jenkins_home
        env:
        - name: LIMITS_MEMORY
          valueFrom:
            resourceFieldRef:
              resource: limits.memory
              divisor: 1Mi
        - name: JAVA_OPTS
          value: -Xmx$(LIMITS_MEMORY)m -XshowSettings:vm -Dhudson.slaves.NodeProvisioner.initialDelay=0 -Dhudson.slaves.NodeProvisioner.MARGIN=50 -Dhudson.slaves.NodeProvisioner.MARGIN0=0.85 -Duser.timezone=Asia/Shanghai
      securityContext:
        fsGroup: 1000
      volumes:
      - name: jenkinshome
        persistentVolumeClaim:
          claimName: opspvc

---
apiVersion: v1
kind: Service
metadata:
  name: jenkins
  namespace: kube-ops
  labels:
    app: jenkins
spec:
  selector:
    app: jenkins
  ports:
  - name: web
    port: 8080
    targetPort: web
  - name: agent
    port: 50000
    targetPort: agent

===

# cat jenkins-ingress.yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: jenkins-ingress
  namespace: kube-ops
  annotations:
    nginx.ingress.kubernetes.io/proxy-body-size: "1024m"
    nginx.ingress.kubernetes.io/proxy-read-timeout: "600"
    nginx.ingress.kubernetes.io/proxy-send-timeout: "600"
    kubernetes.io/ingress.class: "nginx"
spec:
  rules:
  - host: jenkins.vonedao.com
    http:
      paths:
      - backend:
          serviceName: jenkins
          servicePort: 8080