<p>If the application listens on loopback only by default it's ports couldn't be accessible by other pods. port-forward works because it ignores IP addresses and kubelet makes a proxy.</p>

CC BY-SA 4.0
2022-01-22T10:28:49.003Z
2022-01-22T10:28:49.003Z
chupasaurus
<p>I'm having a really strange issue with a particular application that's using the same Helm chart as many other apps in our cluster, and all the others are working fine.</p>
<p>The pods are running the application fine, I can port-forward to any pod, or the service, and see the app locally.</p>
<p>However when I try connecting to it from the ingress via the internet, I get a 502 error from NGINX. Even stranger, when I add liveness and readiness probes to the deployment, those are unable to connect either.</p>
<p>Again, this app uses the exact same Helm chart and config as many other apps that are working, and I can't find anything that's different about it between any other application. Somehow, the pods work but the cluster is unable to reach them internally. What could cause one particular deployment to act this way?</p>

CC BY-SA 4.0
2022-01-21T06:40:48.330Z
Does the app listen on loopback only?
chupasaurus
CC BY-SA 4.0
2022-01-21T11:55:18.653Z
Also, are you using Network Policies by any chance?
luislhl
CC BY-SA 4.0
2022-01-21T19:19:28.447Z
@chupasaurus Thank you! I knew it was something that simple. Yeah all the other apps I've launched with this chart previously were listening on all IPs by default so I never noticed this issue before. This new app was set to localhost only by default. If you post an answer I'll accept.
chrispytoes
<kubernetes>
Ingress and liveness probes unable to connect to pod, but works via port-forward
chrispytoes
# Ingress and liveness probes unable to connect to pod, but works via port-forward

(Asked by: username_0 on 2022-01-20)

I'm having a really strange issue with a particular application that's using the same Helm chart as many other apps in our cluster, and all the others are working fine.

The pods are running the application fine, I can port-forward to any pod, or the service, and see the app locally.

However when I try connecting to it from the ingress via the internet, I get a 502 error from NGINX. Even stranger, when I add liveness and readiness probes to the deployment, those are unable to connect either.

Again, this app uses the exact same Helm chart and config as many other apps that are working, and I can't find anything that's different about it between any other application. Somehow, the pods work but the cluster is unable to reach them internally. What could cause one particular deployment to act this way?

**Tags:** kubernetes

> **Comments:**
> **username_1**: Does the app listen on loopback only?  
> **username_2**: Also, are you using Network Policies by any chance?  
> **username_0**: @username_1 Thank you! I knew it was something that simple. Yeah all the other apps I've launched with this chart previously were listening on all IPs by default so I never noticed this issue before. This new app was set to localhost only by default. If you post an answer I'll accept.  

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## 1 answers

### Answer by username_1 on 2022-01-22. Score: 0 | Accepted answer

If the application listens on loopback only by default it's ports couldn't be accessible by other pods. port-forward works because it ignores IP addresses and kubelet makes a proxy.


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