Error map
default backend - 404 Ingress returns "404 Not Found" / "default backend - 404" (ingress-nginx)
Kubernetes · layer 6, Platform & cloud
Centre: this error. First ring: errors it is linked with (10). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (10)
HTTP 404 Not Found
The server can’t find anything at the requested URL.
Error Domain=NSURLErrorDomain Code=-1001 "The request timed out."
The server didn’t respond within URLSession’s timeout (60 s default) — slow server, unreachable host on this network, or a stalle…
android.os.NetworkOnMainThreadException
The app made a network call on the main (UI) thread, which Android forbids.
DNS not working inside a Kubernetes pod (could not resolve host / nslookup: can't resolve)
Pods can’t resolve service names or external hosts — CoreDNS is down, blocked by NetworkPolicy, or the upstream resolver fails.
Failed to create pod sandbox: plugin type="calico" failed (add): ... (FailedCreatePodSandBox)
The kubelet couldn’t set up the pod’s network sandbox — almost always a CNI plugin problem or exhausted pod IPs.
spec.ports[0].nodePort: Invalid value: 80: provided port is not in the valid range. The range of valid ports is 30000-32767
A NodePort Service asked for a port outside the cluster’s NodePort range (default 30000–32767).
Error from server: admission webhook "validate.nginx.ingress.kubernetes.io" denied the request
A validating admission webhook (ingress-nginx, Gatekeeper/OPA, Kyverno) inspected your object and rejected it; the reason follows…
ECS task stopped: CannotPullContainerError: pull image manifest has been retried ... / ref pull has been retried
The ECS task couldn’t pull its image — no network route to the registry, missing ECR permissions, or a wrong image tag.
HttpRequestException: No connection could be made because the target machine actively refused it (localhost:5001)
Nothing is listening on the host/port the client called — the API isn’t running, uses another port, or the container/network addr…
Service has no endpoints (no endpoints available for service / Endpoints: <none>)
The Service’s selector matches no ready pods, so traffic to it is refused or returns 503.
Two steps away (29)
HTTP 403 Forbidden
The server understood the request but refuses to authorize it — you (or the server process) are not allowed to access this resour…
HTTP 405 Method Not Allowed
The URL exists, but it doesn’t accept the HTTP method you used (e.g. POST to a GET-only route).
HTTP 410 Gone
The resource used to exist but was intentionally and permanently removed, with no forwarding address.
MySQL ERROR 2006 (HY000): MySQL server has gone away
The connection to MySQL was closed — usually by a timeout or a packet larger than `max_allowed_packet`.
HTTP 408 Request Timeout
The server closed the connection because the client took too long to send the complete request.
HTTP 499 Client Closed Request (Nginx)
Nginx-specific code logged when the client disconnected before the server finished responding.
Error response from daemon: network X not found
The container or Compose project refers to a Docker network that doesn’t exist (any more).
Error response from daemon: Pool overlaps with other one on this address space
Docker tried to create a network whose subnet clashes with an existing Docker network (or a VPN/host route).
driver failed programming external connectivity on endpoint: iptables: No chain/target/match by that name
Docker’s iptables rules were wiped (firewalld/ufw reload, iptables flush) while Docker was running, so it can’t publish ports.
Error: getaddrinfo ENOTFOUND host / Name or service not known
DNS lookup for the hostname failed — the name is wrong, doesn’t exist, or this machine can’t resolve it.
net::ERR_NAME_NOT_RESOLVED (This site can't be reached — server IP address could not be found)
DNS couldn’t resolve the hostname in the browser.
cURL error 6: Could not resolve host: api.example.com
PHP cURL couldn’t resolve the hostname via DNS.
Kubernetes: Pod Evicted — The node was low on resource: memory / ephemeral-storage
The kubelet removed the pod because its node ran short of memory or disk.
Kubernetes node NotReady (Kubelet stopped posting node status)
The control plane hasn’t heard from a node’s kubelet, or the kubelet reports a problem — pods there stop being scheduled and are…
Job for nginx.service failed because the control process exited with error code
systemd tried to start the service, but its start command failed. The real reason is in the service’s status/journal.
Failed to start x.service: Unit x.service not found
systemd has no unit with that name — the package isn’t installed, the name differs on this distro, or a new unit file wasn’t load…
systemd: Start request repeated too quickly / service hit its start limit
The service crashed and restarted several times in a short period, so systemd stopped trying (StartLimitBurst).
Kubernetes: CrashLoopBackOff
The container starts, crashes (or exits), and Kubernetes keeps restarting it with increasing back-off delays.
Kubernetes: CreateContainerConfigError — secret / configmap not found
Kubernetes can’t build the container’s configuration — usually a referenced Secret, ConfigMap or key doesn’t exist in that namesp…
Pod status CreateContainerError
The image was pulled, but the container runtime failed to create the container — bad command, missing mount target, or a name/vol…
Kubernetes: ImagePullBackOff / ErrImagePull
The node can’t pull the container image — wrong name/tag, missing registry credentials, or registry unreachable.
npm ERR! code EROFS — EROFS: read-only file system
npm tried to write to a read-only location (read-only container filesystem, mounted volume, or system path).
denied: Your authorization token has expired. Reauthenticate and try again. (Amazon ECR)
Docker’s login to Amazon ECR has expired — ECR tokens last 12 hours, so pushes and pulls fail until you log in again.
Error: connect ECONNREFUSED 127.0.0.1:5432
Nothing is listening at that host:port — the target service is down or you’re connecting to the wrong address.
System.IO.IOException: Failed to bind to address http://127.0.0.1:5000: address already in use
Kestrel can’t listen because another process (often a previous run of the same app) uses the port.
HttpRequestException: The SSL connection could not be established, see inner exception. (AuthenticationException: The remote certificate is invalid)
HttpClient couldn’t complete the TLS handshake — untrusted/self-signed certificate, name mismatch, expired certificate, or TLS ve…
HTTP 503 Service Unavailable
The server is temporarily unable to handle the request — overloaded, in maintenance, or has no healthy backends.
Readiness probe failed: HTTP probe failed with statuscode: 503 / connect: connection refused
The container is running, but its readiness check fails, so the pod is marked not ready and removed from Service endpoints.
Windows Update error 0x80070422 (service is disabled)
Windows Update (or the Microsoft Store/Defender) can’t run because a required service — usually Windows Update (wuauserv) — is di…
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