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?