A Service With Endpoints and No Traffic

Services and Networking / Guide 39 of 44 / Intermediate

• Kubernetes1.36.4
• Cluster4 nodes
• Runtimecontainerd 2.2.6
• CNICalico v3.32.1
• TimeAbout 15 min

curl's exit codes are the diagnosis here: 7 is a failure to connect, 28 is a timeout, and they mean different things.

This guide includes

Use this when a Service has endpoints and still refuses connections. This matters because it passes every check people run first - the selector matches, the Pods are Ready, the slice is populated - and the fault is one number further down.

• building a Service that looks entirely healthy and serves nothing at all
• reading curl's exit code, where 7 is a refusal rather than a timeout
• lining up the three numbers that have to agree - port, targetPort, and what the container serves
• asking the container from inside what it is genuinely listening on
• patching the single wrong field and proving the fix

Before you start

• guide 66 - the failure where there are no endpoints at all, which this one is deliberately not.

1. 1

   A Service that looks entirely healthy

2. 2

   Prove the symptom from a client

3. 3

   Read the three numbers that have to agree

4. 4

   Ask the container what it is actually listening on

5. 5

   Fix the one field and prove it

Official sources

• Service
• Debug Services