本篇文章介绍了如何给pod配置host域名解析
当 DNS 配置以及其它选项不合理的时候，通过向 Pod 的 /etc/hosts 文件中添加条目，可以在 Pod 级别覆盖对主机名的解析。在 1.7 版本后，用户可以通过 PodSpec 的 HostAliases 字段来添加这些自定义的条目。
建议通过使用 HostAliases 来进行修改，因为该文件由 Kubelet 管理，并且可以在 Pod 创建/重启过程中被重写
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| apiVersion: apps/v1beta2
kind: Deployment
metadata:
annotations:
deployment.kubernetes.io/revision: "2"
creationTimestamp: "2020-09-11T08:35:00Z"
generation: 2
labels:
k8s-app: nginx-hosts-alis
qcloud-app: nginx-hosts-alis
name: nginx-hosts-alis
namespace: test
resourceVersion: "12673987137"
selfLink: /apis/apps/v1beta2/namespaces/test/deployments/nginx-hosts-alis
uid: 61493e8e-b0c9-4b5d-a031-6ea2799e9de8
spec:
progressDeadlineSeconds: 600
replicas: 1
revisionHistoryLimit: 10
selector:
matchLabels:
k8s-app: nginx-hosts-alis
qcloud-app: nginx-hosts-alis
strategy:
rollingUpdate:
maxSurge: 1
maxUnavailable: 0
type: RollingUpdate
template:
metadata:
creationTimestamp: null
labels:
k8s-app: nginx-hosts-alis
qcloud-app: nginx-hosts-alis
spec:
containers:
- image: nginx
imagePullPolicy: Always
name: nginx-hosts-alis
resources:
limits:
cpu: 500m
memory: 1Gi
requests:
cpu: 250m
memory: 256Mi
securityContext:
privileged: false
terminationMessagePath: /dev/termination-log
terminationMessagePolicy: File
dnsPolicy: ClusterFirst
hostAliases:
- hostnames:
- foo.local
- bar.local
ip: 127.0.0.1
- hostnames:
- foo.remote
- bar.remote
ip: 10.1.2.3
restartPolicy: Always
schedulerName: default-scheduler
securityContext: {}
terminationGracePeriodSeconds: 30
|
yaml修改好之后，我们可以进入pod内进行验证，查看下pod的/etc/hosts文件是否有加上配置的域名解析
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| root@nginx-hosts-alis-5db8d7c54c-gf6km:/# 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
172.16.2.188 nginx-hosts-alis-5db8d7c54c-gf6km
# Entries added by HostAliases.
127.0.0.1 foo.local bar.local
10.1.2.3 foo.remote bar.remote
|
从上面的结果看，这里域名解析已经加入到对应的pod中。
注意事项：这里修改yaml需要注意字段的缩进，HostAliases是在.spec.hostAliases这个层级，和containers是同级的。