Custom error pages for Nginx Ingress controller

When the custom-http-errors option is enabled, the Ingress controller configures NGINX so that it passes several HTTP headers down to its default-backend in case of error:

Header	Value
X-Code	HTTP status code returned by the request
X-Format	Value of the Accept header sent by the client
X-Original-URI	URI that caused the error
X-Namespace	Namespace where the backend Service is located
X-Ingress-Name	Name of the Ingress where the backend is defined
X-Service-Name	Name of the Service backing the backend
X-Service-Port	Port number of the Service backing the backend
X-Request-ID	Unique ID that identifies the request - same as for backend service

custom-error-pages returns JSON or HTML based on the Accept header sent by the client.

Here's an example of a 503 text/html response:

And here's the application/json response:

{
  "code": "404",
  "title": "Not Found",
  "messages": [
    "The page you're looking for could not be found."
  ],
  "details": {
    "originalURI": "/status/404",
    "namespace": "default",
    "ingressName": "podinfo",
    "serviceName": "podinfo",
    "servicePort": "9898",
    "requestId": "3a35542b0611d3ee0915e196bffac546"
  }
}

custom-error-pages supports 404, 500, 503 and 5xx error codes.

Configurations

Flag	Evironment variable	Default	Description
--debug	DEBUG	false	enable debug log
--error-files-path	ERROR_FILES_PATH	./themes/knockout	the location on disk of files served by the handler
--hide-details	HIDE_DETAILS	false	hide request details in response
--http-listen-address	HTTP_LISTEN_ADDRESS	:8080	http server address
--log-color	LOG_COLOR	false	sets log format to human-friendly, colorized output

Getting started - Locally go get

go get github.com/181192/custom-error-pages && custom-error-pages

Getting started - Locally docker

docker run --rm -p 8080:8080 ghcr.io/181192/custom-error-pages

Or build locally

docker build -t custom-error-pages .
docker run --rm -p 8080:8080 custom-error-pages:latest

Getting started - Ingress Nginx Helm chart

1. Set the custom-http-errors config value
2. Enable default backend
3. Set the default backend image

controller:
  config:
    custom-http-errors: 404,500,501,502,503
defaultBackend:
  enabled: true
  image:
    repository: ghcr.io/181192/custom-error-pages
    tag: latest
  # optional: change path to theme
  extraEnvs:
  - name: ERROR_FILES_PATH
    value: ./themes/knockout

Getting started - Kustomize

Kustomize manifest are provided with both ingress controller and default backend deployment.

kubectl apply -k k8s/
Or
kustomize build k8s | kubectl apply -f -

Credits

• Themes ghost, l7-dark, l7-light, noise and shuffle are from tarampampam/error-pages.