Redirect from/to www with nginx-ingress

Question

I have a kubernetes cluster with nginx-ingress and I try to redirect http://test.domain.com to http://www.test.domaine.com with nginx.ingress.kubernetes.io/from-to-www-redirect annotation.

But it doesn't seem to work.

My ingress resource:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: app-ingress
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/from-to-www-redirect: "true"
spec:
  rules:
  - host: www.test.domain.com
    http:
      paths:
      - path: /
        backend:
          serviceName: app
          servicePort: 8080
  - host: test.domain.com
    http:
      paths:
      - path: /
        backend:
          serviceName: app
          servicePort: 8080

I have tried many configurations but I can't make it work. The nginx.ingress.kubernetes.io/from-to-www-redirect annotation has no effect!

Answer 1

Something like this should work:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: app-ingress
  annotations:
    nginx.ingress.kubernetes.io/from-to-www-redirect: "true"
    cert-manager.io/cluster-issuer: letsencrypt
spec:
  ingressClassName: nginx
  rules:
    - host: www.test.domain.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: app
                port:
                  number: 8080
  tls:
    - hosts:
        - www.test.domain.com
        - test.domain.com
      secretName: your-cert-secret

If you don't use TLS, you can safely remove the tls section and the line mentioning cert-manager. Also, the line mentioning cert-manager only works if you've configured a certificate with Cert Manager.

Note that since the question was asked, the APIs have changed a bit, which is why the apiVersion is now networking.k8s.io/v1 and the ingress class is specified in ingressClassName, not the ingress.class annotation.

Answer 2

kind: Ingress
apiVersion: networking.k8s.io/v1
metadata:
  name: webui-ingress
  namespace: default
  annotations:
    kubernetes.io/ingress.allow-http: 'false'
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/affinity: cookie
    nginx.ingress.kubernetes.io/configuration-snippet: |
      more_set_headers "X-Frame-Options: SAMEORIGIN";
      more_set_headers "X-Xss-Protection: 0";
      more_set_headers "Referrer-Policy: use strict-origin-when-cross-origin";
      if ($host = 'test.domain.com' ) {
         return 301 https://www.test.domain.com ;
      }
    nginx.ingress.kubernetes.io/force-ssl-redirect: 'true'
    nginx.ingress.kubernetes.io/proxy-body-size: 10m
    nginx.ingress.kubernetes.io/rewrite-target: /
    nginx.ingress.kubernetes.io/session-cookie-hash: sha1
    nginx.ingress.kubernetes.io/session-cookie-name: route
    nginx.ingress.kubernetes.io/ssl-passthrough: 'true'
    nginx.ingress.kubernetes.io/ssl-redirect: 'true'
spec:
  tls:
    - hosts:
        - test.domain.com
      secretName: test-tls
    - hosts:
        - www.test.domain.com
      secretName: www-tls
  rules:
    - host: test.domain.com
      http:
        paths:
          - path: /
            pathType: ImplementationSpecific
            backend:
              service:
                name: webui
                port:
                  number: 8022
    - host: www.test.domain.com
      http:
        paths:
          - path: /
            pathType: ImplementationSpecific
            backend:
              service:
                name: webui
                port:
                  number: 8022

once the below annotation is added your domain will redirect to www

nginx.ingress.kubernetes.io/configuration-snippet: |
  more_set_headers "X-Frame-Options: SAMEORIGIN";
  more_set_headers "X-Xss-Protection: 0";
  more_set_headers "Referrer-Policy: use strict-origin-when-cross-origin";
  if ($host = 'test.domain.com' ) {
     return 301 https://www.test.domain.com ;
  }

Answer 3

This is a community wiki answer. Feel free to expand it.

In order to make it work you also need to use the nginx.ingress.kubernetes.io/configuration-snippet annotation. For example:

nginx.ingress.kubernetes.io/configuration-snippet: |
  if ($host = 'example.com' ) {
    rewrite ^ https://www.example.com$request_uri permanent;
  }

As already mentioned by @apoorvakamath in the comments, you can refer to this guide for a step by step detailed example:

The snippet is the clever aspect fo the solution. It allows you to add dynamic configuration to the ingress controller. We use it to detect the use of the non-www form of the URL and then simply issue a re-write that is pushed out (and back via your domain) to the www form.