HTTP to HTTPS redirect with kong-ingress and TLS-offloading

Kubernetes
#1

Hi all.

I’m having issues setting up HTTP to HTTPS redirect on the kong ingress while using AWS ELB (classic) and HTTPS listener for TLS offloading. With the current configuration no matter whether the request arrives via HTTP or HTTPS kong issues 302 redirect. By the looks of it Kong is not handling the X-Forward-Proto header supplied by the ELB.

I have followed the posts in the forum about similar issue (Redirecting HTTP to HTTPS) but so far it doesn’t seem that anyone had success implementing proper HTTP to HTTPS redirect with TLS offloading or am I configuring Kong incorrectly?

Thanks in advance for any hints!

The Kong ingress is provisioned using the stable/kong Helm chart.
Some relevant bits from values.yaml:

proxy:
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-backend-protocol: http
    service.beta.kubernetes.io/aws-load-balancer-connection-idle-timeout: "3600"
    service.beta.kubernetes.io/aws-load-balancer-ssl-cert: arn:aws:acm:eu-west-2:XXXX
    service.beta.kubernetes.io/aws-load-balancer-ssl-ports: 443
  http:
    enabled: true
    servicePort: 80
    containerPort: 8000
  tls:
    enabled: true
    servicePort: 443
    containerPort: 8443
    overrideServiceTargetPort: 8000 # <=

---
apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  name: adminer
  annotations:
    kubernetes.io/ingress.class: kong
    configuration.konghq.com: ingress-api
spec:
  rules:
    - host: XXXX
      http:
        paths:
          - path: /
            backend:
              serviceName: adminer
              servicePort: 80

apiVersion: configuration.konghq.com/v1
kind: KongIngress
metadata:
  name: ingress-api
route:
  protocols:
    - https
  https_redirect_status_code: 302
Kong Ingress Annotations (Redirect)
#2

You need to set KONG_TRUSTED_IPS environment variable so that Kong trusts the headers sent by ELB:

#3

Hi @hbagdi @thecodingrobot

I have the same issue. Were you able to resolve it?

Ingress and KongIngress definitions:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: "2048-ingress"
  namespace: "2048-game"
  annotations:
    kubernetes.io/ingress.class: kong
    kubernetes.io/tls-acme: "true"
    configuration.konghq.com: https-only
  labels:
    app: 2048-ingress
spec:
  rules:
    - host: 2048.test.com
      http:
        paths:
          - path: /
            backend:
              serviceName: "service-2048"
              servicePort: 80
---
apiVersion: configuration.konghq.com/v1
kind: KongIngress
metadata:
    name: https-only
    namespace: 2048-game
route:
  protocols:
  - https
  https_redirect_status_code: 302

Both HTTP and HTTPS are redirected causing loop.

sh-4.2$ curl -I http://2048.test.com
HTTP/1.1 302 Moved Temporarily
Date: Tue, 11 Feb 2020 16:07:26 GMT
Content-Type: text/html
Content-Length: 110
Connection: keep-alive
Location: https://2048.test.com
X-Kong-Response-Latency: 0
Server: kong/1.4.3

sh-4.2$ curl -I https://2048.test.com
HTTP/1.1 302 Moved Temporarily
Date: Tue, 11 Feb 2020 16:07:33 GMT
Content-Type: text/html
Content-Length: 110
Connection: keep-alive
Location: https://2048.test.com
X-Kong-Response-Latency: 1
Server: kong/1.4.3
SSL Redirect from http to https
#4

Can you set KONG_TRUSTED_IPS=0.0.0.0/0 and try?

#5

@hbagdi, thanks for reply. I have updated the ingress-kong deployment env variables to add the KONG_TRUSTED_IPS. Is that what you mean? The result is the same, both http and https is being redirected to https causing loop.

spec:
  containers:
  - env:
    - name: KONG_DATABASE
      value: "off"
    - name: KONG_NGINX_WORKER_PROCESSES
      value: "1"
    - name: KONG_NGINX_HTTP_INCLUDE
      value: /kong/servers.conf
    - name: KONG_ADMIN_ACCESS_LOG
      value: /dev/stdout
    - name: KONG_ADMIN_ERROR_LOG
      value: /dev/stderr
    - name: KONG_ADMIN_LISTEN
      value: 127.0.0.1:8444 ssl
    - name: KONG_PROXY_LISTEN
      value: 0.0.0.0:8000, 0.0.0.0:8443 ssl http2
    - name: KONG_TRUSTED_IPS
      value: 0.0.0.0/0
#6 
KONG_TRUSTED_IPS=0.0.0.0/0,::/0

Can you change trusted ips to that?

To make sure, are you using ELB or NLB? ELB supports x-forwarded-proto and this should work with that configuration.

Kong correctly parses forwarded-proto and matches the route accordingly. I tested this locally to make sure of it.

#7

It worked! I’m using ELB. Only the http is redirected to https now, so loop issue was resolved. Thanks a lot @hbagdi.

#8

We should add this to docs somewhere. I’m not sure where though.

#9

I’ve been able to confirm this works in my use case. However, I’m wondering how this would work in the context of a Helm chart. Looking through the templates, it doesn’t seem supported.

Would it be useful if I created a PR to allow this as an env parameter?

#10

Looks like this is already handled here

#11

Hi,
What about NLB ? Is there a way to configure HTTP to HTTPS redirection with that load balancer ?
Thanks,

#12

The same approach should work if you are terminating HTTP at NLB.

#13

Hi @hbagdi,

I’m using nlb and facing The plain HTTP request was sent to HTTPS port, i tried adding KONG_TRUSTED_IPS to kong deployment but no luck.
below is my kong-proxy service

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-backend-protocol: http
    service.beta.kubernetes.io/aws-load-balancer-connection-idle-timeout: "3600"
    service.beta.kubernetes.io/aws-load-balancer-ssl-cert: arn:aws:acm:...
    service.beta.kubernetes.io/aws-load-balancer-ssl-ports: "443"
    service.beta.kubernetes.io/aws-load-balancer-type: nlb

  ports:
  - name: proxy
    nodePort: 31193
    port: 80
    protocol: TCP
    targetPort: 8000
  - name: proxy-ssl
    nodePort: 30102
    port: 443
    protocol: TCP
    targetPort: 8443

and my ingress be like:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    konghq.com/override: https-only
    konghq.com/strip-path: "true"

and ingress-kong pod variables:

Environment:
  KONG_PROXY_LISTEN:            0.0.0.0:8000, 0.0.0.0:8443 ssl http2
  KONG_PORT_MAPS:               80:8000, 443:8443
  KONG_ADMIN_LISTEN:            127.0.0.1:8444 ssl
  KONG_STATUS_LISTEN:           0.0.0.0:8100
  KONG_DATABASE:                off
  KONG_NGINX_WORKER_PROCESSES:  2
  KONG_ADMIN_ACCESS_LOG:        /dev/stdout
  KONG_ADMIN_ERROR_LOG:         /dev/stderr
  KONG_PROXY_ERROR_LOG:         /dev/stderr
  KONG_TRUSTED_IPS:             0.0.0.0/0, ::/0

If i change proxy-ssl target port to 8000 then got a redirect loop

  - name: proxy-ssl
    nodePort: 30102
    port: 443
    protocol: TCP
    targetPort: 8000

Not sure what i’m missing here. Thank you in advance !

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