kubernetes - 解析 headless 服务的 IP 地址

Question

我创建了一个服务，它分配了 3 个 Pod。

我想通过同一项目中的其他服务通过其主机名访问该服务。我怎样才能做到这一点？

尝试过:

alxtbk@dns-test:~$ ping elassandra-0.elassandra
ping: elassandra-0.elassandra: Name or service not known

alxtbk@dns-test:~$ ping elassandra-0.default.svc.cluster.local
ping: elassandra-0.default.svc.cluster.local: Name or service not known

alxtbk@dns-test:~$ ping elassandra.default.svc.cluster.local
ping: elassandra.default.svc.cluster.local: Name or service not known

解析 headless 服务的IP地址的正确方法是什么？

Answer 1

For such Services, a cluster IP is not allocated, kube-proxy does not handle these services, and there is no load balancing or proxying done by the platform for them. How DNS is automatically configured depends on whether the service has selectors defined.

With selectors

For headless services that define selectors, the endpoints controller creates Endpoints records in the API, and modifies the DNS configuration to return A records (addresses) that point directly to the Pods backing the Service.

Without selectors

For headless services that do not define selectors, the endpoints controller does not create Endpoints records. However, the DNS system looks for and configures either:

CNAME records for ExternalName-type services.

A records for any Endpoints that share a name with the service, for all other types.

所以你也许可以这样做:

kubectl get ep

获取端点，然后在另一个 kubernetes 服务中使用它们。