k8s deployment 添加hosts

在使用k8s 中，难免有一些实例需要添加hosts绑定

最土的办法就是把这个hosts写在dockfile里。

实际k8s已经解决了这样的问题。

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

例子中是pod，下面是RC、deployment 的yaml

apiVersion: v1
kind: ReplicationController
metadata:
  name: dp-rc
  namespace: default
spec:
  replicas: 1
  selector:
    name: dp-pod
  template:
    metadata:
      labels:
        name: dp-pod
    spec:
      hostAliases:
      - ip: 192.168.176.247
        hostnames:
        - "dccas.finupgroup.com"
      containers:
      - name: dp
        image: reg.k8s.dc.finupgroup.com/datacenter/dp:latest
        imagePullPolicy: Always
        ports:
        - containerPort: 8080

验证

[root@p1 ~]# kubectl exec -it dp-rc-kt8jg bash
Defaulting container name to dp.
Use 'kubectl describe pod/dp-rc-kt8jg -n default' to see all of the containers in this pod.
bash-4.2#
bash-4.2# 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
10.254.12.2 dp-rc-kt8jg

# Entries added by HostAliases.
192.168.176.247 dccas.finupgroup.com