Ingress HTTP Routing
8 incident problems about Ingress HTTP Routing. Start with the reviewed ones.
Read first
When the ConfigMap changed but the Pod keeps using the old valuesAn InfraTree guide that lays out the first signals to check, the CLI verification order, common misdiagnoses, and a safe recovery path when values don't refresh after a ConfigMap update because of envFrom, subPath, volume projection, or rollout trigger differences.Kubernetes3 min readWhen CoreDNS is Running but only DNS lookups failAn InfraTree guide that lays out the first signals to check, the CLI verification order, common misdiagnoses, and a safe recovery path when the CoreDNS Pod looks healthy but failures occur in the kube-dns path, upstream, node-local-dns, or policy.Kubernetes3 min readWhat to check first when CrashLoopBackOff appearsAn InfraTree guide that lays out the first signals to check, the CLI verification order, common misdiagnoses, and a safe recovery path when a Pod restarts repeatedly and the real cause is left in the previous logs and events.Kubernetes3 min read
Recommended problems
Reviewed problems first, then problems with detailed scenarios.
All problems (8)
K8S-1199kubectl port-forward works but ingress still failsA team confirms the app with kubectl port-forward and assumes ingress must be fine. The actual failure sits earlier in the edge-hostname or path-rewrite chain.KubernetesIntermediate18 minProK8S-1238An ingress route looks valid but one hostname still returns 404After adding or upgrading an ingress controller, one hostname starts returning the wrong response even though the Ingress object itself looks unchanged.KubernetesAdvanced20 minProK8S-1219ALB controller says permissions are correct but one action still failsAn ALB controller works enough to create some resources but repeatedly fails one reconciliation action.KubernetesAdvanced21 minProK8S-1227The ALB controller creates the load balancer but target registration failsAn Ingress object becomes active but downstream target health stays red after registration.KubernetesAdvanced21 minProK8S-1215Target group health is green but some client traffic still blackholesAn NLB-backed service passes health checks overall, but a portion of client traffic still disappears during scale changes.KubernetesAdvanced22 minProK8S-1209One ingress route still breaks WebSocket upgradesA platform keeps WebSockets behind ingress plus an edge proxy and only one upgraded route returns 400.KubernetesAdvanced23 minProK8S-1203Ingress health looks good but one path still 404sA rewrite snippet copied from community answers works for one route. Another path still 404s because an upstream edge layer is also transforming the path unexpectedly.KubernetesAdvanced22 minProK8S-1183Ingress NGINX returns 400 on WebSocket pathA public ingress-nginx snippet was copied into production. Browser requests work until the WebSocket path crosses an extra proxy boundary.KubernetesIntermediate24 minPro