创建pod的时候，pod会在其/etc/hosts里面添加一个条目。

[root@master ~]# kubectl get pod -o wide
NAME                     READY   STATUS    RESTARTS   AGE     IP             NODE    NOMINATED NODE   READINESS GATES
dns-test                 1/1     Running   0          24h     10.233.90.31   node1   <none>           <none>

[root@master ~]# kubectl exec -it dns-test sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
/ # 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
10.233.90.31	dns-test        #左边是pod的IP，右边是pod的名称

可不可以在创建pod的时候指定一些条目在hosts里面？这个是可以的！

上面就是可以将aa/bb.local可以解析为10.1.1.1的地址。 cc/dd.local就可以解析为10.1.1.2的地址。

[root@master pod]# cat nginx.yaml 
apiVersion: v1
kind: Pod
metadata:
  labels:
    app: nginx
  name: nginx
  namespace: default
spec:
  hostAliases:
  - ip: "192.168.26.101"
    hostnames:
    - "vm01"
    - "vm02"
  containers:
  - image: nginx
    imagePullPolicy: Always
    name: nginx
  dnsPolicy: ClusterFirst

[root@master pod]# kubectl apply -f nginx.yaml 
pod/nginx created

[root@master pod]# kubectl exec -it nginx  sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
# 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
10.233.96.9	nginx

# Entries added by HostAliases.
192.168.26.101	vm01	vm02

这样就完成添加hosts解析了！