Ingress: default backend - 404

Quick fix

Read the commands before running them. Anything that restarts a service, deletes data or changes permissions should be tried on a non-production system first.

# Check ingress rules
kubectl get ingress -A
# Verify host matches
kubectl describe ingress my-ingress
# Check the request host header
curl -H 'Host: myapp.example.com' http://<ingress-ip>
# Ensure DNS points to ingress controller

How to diagnose Ingress errors

An Ingress failure is a routing failure, and there are only a few places it can break: the IngressClass is missing so no controller claims the resource, the path or host does not match, the backing Service has no endpoints, or the TLS secret is absent or in the wrong namespace. The "default backend - 404" page is the controller saying it received the request but found no rule for it.

If the quick fix above does not resolve it, work through these steps. They apply to this whole class of error, not just to this one message, which is usually what saves the time.

1. Work backwards from the pod: kubectl get endpoints <service>. If it is empty, the Service selector does not match any ready pod and no Ingress configuration will help.
2. Check that a controller has claimed the Ingress: kubectl describe ingress <name> should show events and an assigned address. No address means no controller is watching that IngressClass.
3. Read the controller's own logs (kubectl logs -n ingress-nginx deploy/ingress-nginx-controller). They log rejected configuration and certificate problems explicitly.
4. Remember TLS secrets must live in the same namespace as the Ingress. This is the single most common TLS mistake.
5. Verify path type semantics: Prefix, Exact and ImplementationSpecific match differently, and regex behaviour varies between controllers.

Tools worth reaching for

• kubectl describe ingress
• kubectl get endpoints
• controller logs
• curl -H 'Host: …'
• openssl s_client -servername

Authoritative references

Primary documentation for this error, worth reading before applying any fix in production.

📖 kubernetes.io

Related Ingress errors

• cert-manager: Order is pending / challenge failed to propagatecert-manager created an ACME order but the challenge never validated. For HTTP-01 the…
• Ingress: configuration-snippet annotation cannot be usedingress-nginx 1.9 turned allow-snippet-annotations off by default after snippets were shown…
• Ingress: path not matching any backendThe request path does not match any rule defined in the Ingress resource. May be a pathType…
• Ingress: TLS secret not foundThe TLS secret referenced in the Ingress spec does not exist in the same namespace. HTTPS…
• Ingress: too many redirects (redirect loop)An infinite redirect loop between the ingress controller and backend, usually caused by SSL…
• IngressClass not foundThe specified IngressClass does not exist or no ingress controller is installed that handles…
• Kubernetes Ingress errorIngress controller cannot route traffic to the specified service, often due to misconfigured…

See all 8 Ingress errors →

Browse other categories

• HTTP 494xx client errors, 5xx server errors, redirects, headers and protocol problems.
• JavaScript 42npm resolution, async pitfalls, hydration, memory limits and runtime type…
• Database 41Connections, deadlocks, constraints, replication and memory limits.
• AI 35Rate limits, context windows, GPU memory and model-serving failures.
• Network 35Refused connections, timeouts, resets, MTU problems and port exhaustion.
• Python 35Imports, virtual environments, encoding, concurrency and dependency conflicts.
• Kubernetes 34CrashLoopBackOff, ImagePullBackOff, OOMKilled, RBAC, scheduling and storage.
• Docker 27Daemon connectivity, disk space, image pulls, ports and architecture mismatches.
• System 26Disk space, systemd units, file descriptors, OOM killer and scheduled jobs.
• Cloud 25IAM permissions, quotas, service limits and credential failures.
• Security 25JWT validation, CSRF, OAuth grants, SELinux, SSH host keys and CSP.
• TLS 24Untrusted authorities, expiry, hostname mismatch, chains and cipher negotiation.

Something missing or wrong?

This entry is maintained by hand. If the fix is out of date, incomplete, or you have a better one, email a correction and it will be reviewed.