Understanding DNS resolution on Linux and Kubernetes

It’s possible to tell Kubernetes to use the DNS configuration of the host. This is used, for instance, in the CoreDNS pods, since they need to know which resolvers to query for external names. It’s also used by some infrastructure, essential pods, that need to resolve external names but don’t want to depend on the Kubernetes internal DNS to be avai... See more

Finally, there is that options ndots:5 . This indicates “how many dots should there be in a name for that name to be considered an external name”. In other words, if we try to resolve a , a.b , a.b.c , a.b.c.d , or a.b.c.d.e , the search list will be used - so resolving api.example.com will result in 5 DNS queries (for the 4 elements of the search ... See more