[Kubernetes] Allow to set custom headers on specific paths in ingress

[osamamaruf]

Do you want to request a feature or report a bug?

Feature

What did you expect to see?

ATM annotations cannot be applied on specific paths like e.g. ingress.kubernetes.io/custom-response-headers . For example take the case of applying cache-control headers on static resources like .js, .png files.
We can

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: application-ingress
  namespace: abc
  annotations:
    kubernetes.io/ingress.class: 'traefik'    
	ingress.kubernetes.io/custom-response-headers: Cache-Control: private || Cache-Control: max-age=31536000
spec:
  rules:
  - host: 
    http:
      paths:
      - path: /abc1
        backend:
          serviceName: sabc1
          servicePort: 443
      - path: /abc2
        backend:
          serviceName: sabc2
          servicePort: 443

However the headers will be applied to all the paths. If possible we can apply a regex before specifying the each header to indicate on what files the header should be applied. If no regex is defined then it should apply on all something like this

  annotations:
    kubernetes.io/ingress.class: 'traefik'    
	ingress.kubernetes.io/custom-response-headers: (.js|.png)$ Cache-Control: private || (.js|.png)$ Cache-Control: max-age=31536000

would be good.

Further it would be great if this can be applied to specific path e.g.

- path: /abc1
        annotations:
          ingress.kubernetes.io/custom-response-headers: annotation for specific path
        backend:
          serviceName: sabc1
          servicePort: 443

[codeman9]

I would also like a feature like this, but so that I can support custom request headers while doing service-weights. If the ingress.kubernetes.io/custom-[response,request]-headers was of type map[string]map[string]string, then traefik could support something like:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: application-ingress
  namespace: abc
  annotations:
    kubernetes.io/ingress.class: 'traefik'
    ingress.kubernetes.io/custom-response-headers: |
        sabc1: X-Custom-Response-Header:sabc1
        sabc2: X-Custom-Response-Header:sabc2
    ingress.kubernetes.io/custom-request-headers: |
        sabc1: X-Custom-Host-Header:sabc1.namespace1.svc.cluster.local
        sabc2: X-Custom-Host-Header:sabc2.namespace2.svc.cluster.local
    traefik.ingress.kubernetes.io/service-weights |
        sabc1: 25%
        sabc2: 75%
spec:
  rules:
  - host: mydomain.com
    http:
      paths:
      - path: /abc1
        backend:
          serviceName: sabc1
          servicePort: 443
      - path: /abc1
        backend:
          serviceName: sabc2
          servicePort: 443

because the ingress object can define multiple services in one, it seems to make sense that different headers could be provided to/from each service differently. The key for me is to be able to specify a different custom host header per service so that the next downstream proxy can route accordingly.

[earonesty]

Can't you just have multiple ingress definitions?

[mastoj]

I saw somewhere that nginx supports some kind of templating, so you could write something like:

"ingress.kubernetes.io/custom-request-headers": "l5d-dst-override:$service_name.$namespace.svc.cluster.local:8080"

Not exactly that, but similar. Is that also possible for traefik? If it isn't I need to create multiple ingress definitions.

[prajithp13]

Any work around for this?