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Hands-on Lab·Certified Kubernetes Administrator

Headless and ExternalName Services

The two Service types that are not proxies. A headless Service hands back Pod IPs so a client can choose a member; an ExternalName is a DNS alias with no endpoints, no port mapping and no kube-proxy rules at all.

Services and Networking Guide 51 of 103 Intermediate

Written against the versions above. Pod and cluster IPs are this lab's. The shape of each answer - one address, several addresses, a CNAME - is what to learn.

Four nodes. The two backend Pods landed on different workers, which is what makes the headless lookup return two addresses.
Server NameIP AddressOSRolesCPURAMHDD
CKA1001192.168.0.175Ubuntu 26.04 LTSControl Plane Node2 Core4 GB50 GB
CKA1001-NODE01192.168.0.176Ubuntu 26.04 LTSWorker Node2 Core4 GB50 GB
CKA1001-NODE02192.168.0.177Ubuntu 26.04 LTSWorker Node2 Core4 GB50 GB
CKA1001-NODE03192.168.0.178Ubuntu 26.04 LTSWorker Node2 Core4 GB50 GB

Before you start

  1. Three Services over the same two Pods

  2. What each one resolves to

  3. What has endpoints, and what does not

  4. The failure it is known for

Official sources

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