This example shows how is possible to use a custom backend to render custom error pages. The code of this example is located here custom-error-pages
The idea is to use the headers X-Code and X-Format that NGINX pass to the backend in case of an error to find out the best existent representation of the response to be returned. i.e. if the request contains an Accept header of type json the error should be in that format and not in html (the default in NGINX).
First create the custom backend to use in the Ingress controller
$ kubectl create -f custom-default-backend.yaml
service "nginx-errors" created
replicationcontroller "nginx-errors" created
$ kubectl get svc
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
echoheaders 10.3.0.7 nodes 80/TCP 23d
kubernetes 10.3.0.1 <none> 443/TCP 34d
nginx-errors 10.3.0.102 <none> 80/TCP 11s
$ kubectl get rc
CONTROLLER REPLICAS AGE
echoheaders 1 19d
nginx-errors 1 19s
Next create the Ingress controller executing
$ kubectl create -f rc-custom-errors.yaml
Now to check if this is working we use curl:
$ curl -v http://172.17.4.99/
* Trying 172.17.4.99...
* Connected to 172.17.4.99 (172.17.4.99) port 80 (#0)
> GET / HTTP/1.1
> Host: 172.17.4.99
> User-Agent: curl/7.43.0
> Accept: */*
>
< HTTP/1.1 404 Not Found
< Server: nginx/1.10.0
< Date: Wed, 04 May 2016 02:53:45 GMT
< Content-Type: text/html
< Transfer-Encoding: chunked
< Connection: keep-alive
< Vary: Accept-Encoding
<
<span>The page you're looking for could not be found.</span>
* Connection #0 to host 172.17.4.99 left intact
Specifying json as expected format:
$ curl -v http://172.17.4.99/ -H 'Accept: application/json'
* Trying 172.17.4.99...
* Connected to 172.17.4.99 (172.17.4.99) port 80 (#0)
> GET / HTTP/1.1
> Host: 172.17.4.99
> User-Agent: curl/7.43.0
> Accept: application/json
>
< HTTP/1.1 404 Not Found
< Server: nginx/1.10.0
< Date: Wed, 04 May 2016 02:54:00 GMT
< Content-Type: text/html
< Transfer-Encoding: chunked
< Connection: keep-alive
< Vary: Accept-Encoding
<
{ "message": "The page you're looking for could not be found" }
* Connection #0 to host 172.17.4.99 left intact