Kubernetes/DNS: Difference between revisions

Latest revision as of 06:24, 16 December 2024

https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/

Any Pods exposed by a Service have the following DNS resolution available:

pod-ipv4-address.service-name.my-namespace.svc.cluster-domain.example.

Pod's hostname and subdomain fields ^[1]

Currently when a Pod is created, its hostname (as observed from within the Pod) is the Pod's metadata.name value.
The Pod spec also has an optional subdomain field which can be used to indicate that the pod is part of sub-group of the namespace. For example, a Pod with spec.hostname set to "foo", and spec.subdomain set to "bar", in namespace "my-namespace", will have its hostname set to "foo" and its fully qualified domain name (FQDN) set to "foo.bar.my-namespace.svc.cluster.local" (once more, as observed from within the Pod).

servicename.namespace.svc.cluster.local

ubuntu pod in namespace kenneth: /etc/resolv.conf

search kenneth.svc.cluster.local svc.cluster.local cluster.local EXAMPLE.com
nameserver 172.30.0.10
options ndots:5

@@ Line 1: / Line 1: @@
+== DNS Pod Service ==
+ https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/
+Any Pods exposed by a Service have the following DNS resolution available:
+ pod-ipv4-address.service-name.my-namespace.svc.cluster-domain.example.
+Pod's hostname and subdomain fields <ref>https://kubernetes.io/docs/concepts/services-networking/dns-pod-service/#pod-s-hostname-and-subdomain-fields</ref>
+* Currently when a Pod is created, its hostname (as observed from within the Pod) is the Pod's metadata.name value.
+* The Pod spec also has an optional subdomain field which can be used to indicate that the pod is part of sub-group of the namespace. For example, a Pod with spec.hostname set to "foo", and spec.subdomain set to "bar", in namespace "my-namespace", will have its hostname set to "foo" and its fully qualified domain name (FQDN) set to "foo.bar.my-namespace.svc.cluster.local" (once more, as observed from within the Pod).
+ servicename.namespace.svc.cluster.local
+== Example resolv.conf ==
 ubuntu pod in namespace kenneth:
 /etc/resolv.conf