How service discovery works

Two things are important if you want to understand how service discovery works within and across namespaces:

1. Every cluster has an address space.
2. Namespaces partition the cluster address space.

Every cluster has an address space based on a DNS domain that we usually call the cluster domain. By default, it’s called cluster.local, and Service objects are placed within that address space. For example, a Service called ent will have a fully qualified domain name (FQDN) of ent.default.svc.cluster.local.

The format of the FQDN is <object-name>.<namespace>.svc.cluster.local