kubernetes HostAliases 添加其他主机别名到POD

﹏ヽ暗。殇╰゛Y 2022-05-17 08:58 135阅读 0赞

kubernetes可以通过`.spec.hostAliases`字段添加主机别名，这个功能是在1.7.x以及以上版本提供的

**查看默认的hosts文件**

创建pod

[root@demo ~]# kubectl run nginx --image xxx/hub/nginx:20180808 --generator=run-pod/v1
    pod "nginx" created
    [root@test-master-113 ~]# kubectl get pods 
    NAME      READY     STATUS              RESTARTS   AGE
    nginx     0/1       ContainerCreating   0          3s
    [root@test-master-113 ~]# kubectl get pods 
    NAME      READY     STATUS              RESTARTS   AGE
    nginx     0/1       ContainerCreating   0          5s
    [root@test-master-113 ~]# kubectl get pods 
    NAME      READY     STATUS              RESTARTS   AGE
    nginx     0/1       ContainerCreating   0          6s
    [root@test-master-113 ~]# kubectl get pods 
    NAME      READY     STATUS              RESTARTS   AGE
    nginx     0/1       ContainerCreating   0          7s
    [root@test-master-113 ~]# kubectl get pods 
    NAME      READY     STATUS    RESTARTS   AGE
    nginx     1/1       Running   0          8s
    [root@test-master-113 ~]# kubectl get pods 
    NAME      READY     STATUS    RESTARTS   AGE
    nginx     1/1       Running   0          10s

查看pod的hosts的信息

[root@demo ~]# kubectl exec nginx -- cat /etc/hosts
    # Kubernetes-managed hosts file.
    127.0.0.1   localhost
    ::1 localhost ip6-localhost ip6-loopback
    fe00::0 ip6-localnet
    fe00::0 ip6-mcastprefix
    fe00::1 ip6-allnodes
    fe00::2 ip6-allrouters
    192.168.116.183 nginx

**添加其他host的信息**

使用HostAliases添加其他host信息

添加ip 127.0.0.1 对应的主机名为`foo.local`和 `bar.local`

添加ip 10.1.2.3 对应的主机名为`foo.remote`和 `bar.remote`

如下

apiVersion: v1
    kind: Pod
    metadata:
      name: hostaliases-pod
    spec:
      restartPolicy: Never
      hostAliases:
      - ip: "127.0.0.1"     hostnames:
        - "foo.local"     - "bar.local"   - ip: "10.1.2.3"     hostnames:
        - "foo.remote"     - "bar.remote"   containers:
      - name: cat-hosts     image: harbor.enncloud.cn/hub/nginx:20180808
        command:
        - cat     args:
        - "/etc/hosts"

查看日志

[root@demo qinzhao]# kubectl logs hostaliases-pod
    # Kubernetes-managed hosts file.
    127.0.0.1   localhost
    ::1 localhost ip6-localhost ip6-loopback
    fe00::0 ip6-localnet
    fe00::0 ip6-mcastprefix
    fe00::1 ip6-allnodes
    fe00::2 ip6-allrouters
    192.168.141.26  hostaliases-pod
    127.0.0.1   foo.local
    127.0.0.1   bar.local
    10.1.2.3    foo.remote
    10.1.2.3    bar.remote

参考:[add-entries-to-pod-etc-hosts-with-host-aliases][]

[add-entries-to-pod-etc-hosts-with-host-aliases]: https://kubernetes.io/docs/concepts/services-networking/add-entries-to-pod-etc-hosts-with-host-aliases/