K
Q

Configure .Net Core behind nginx proxy in Kubernetes

7/1/2019

I cannot get my asp.net core websites to work behind an ngnix ingress controller in Kubernetes. I can view the site, but all links, css and images are broken.

My Ingress controller looks like this

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: apps-ingress
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/rewrite-target: /$2
spec:
  rules:
  - host: 
    http:
      paths:
      - path: /web(/|$)(.*)
        backend:
          serviceName: web-service
          servicePort: 80
      - path: /middle(/|$)(.*)
        backend:
          serviceName: middle-api-service
          servicePort: 80

I've also configured my site to use forwarded headers

 app.UseForwardedHeaders(new ForwardedHeadersOptions
 {
      ForwardedHeaders = ForwardedHeaders.All
 });

I can browse to the website at {proxyaddress}/web This loads the site, but all links, css and images break as they go to the root proxy address without the /web that is the configured path for the ingress controller.

I did output the headers that website receives and I can see:

header X-Real-IP - val:  10.240.0.4         
header X-Forwarded-For - val:  10.240.0.4         
header X-Forwarded-Host - val:  {ProxyAddress}       
header X-Forwarded-Port - val:  443         
header X-Forwarded-Proto - val:  https        
header X-Original-URI - val:  /web/        
header X-Scheme - val:  https

I can see the header X-Original-URI has the value of /web which my website needs to use as its base for all links.

I've tried app.UsePathBase("/web"); and

app.UseForwardedHeaders(new ForwardedHeadersOptions
            {
                ForwardedForHeaderName = "X-Original-URI",
                OriginalForHeaderName = "X-Original-URI",
                OriginalHostHeaderName = "X-Original-URI",
                ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto
            });

Nothing seems to work, and I cannot find any info online as to what I need to set to get the website to work under the path of /web thats configured by the proxy?

-- Steve
asp.net-core
c#
kubernetes
nginx

Similar Questions

Local singularity image in snakemake workflow on AWS eks with --kubernetes option
Airflow - Conditional retry in KubernetesPodOperator
How to simulate Power Failure In Kubernetes
Website images work locally on Minikube but not remotely on GKE

1 Answer

7/2/2019

I found the answer, because I'm using a path base on the nginx proxy of /web

Instead of rewriting the target so that the controllers won't return a 404 in the asp.net core app, you need to leave the path as it is with the /web

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: apps-ingress
  labels:
    name: apps-ingress
  annotations:
    kubernetes.io/ingress.class: nginx
spec:
  rules:
  - host: 
    http:
      paths:
      - path: /web
        backend:
          serviceName: web
          servicePort: 80
      - path: /middle
        backend:
          serviceName: middle-api
          servicePort: 80

and then configure the path base to equal /web in the app configure section.

 public void Configure(IApplicationBuilder app, IHostingEnvironment env)
        {
            if (!String.IsNullOrEmpty(Configuration["PathBase"]))
                app.UsePathBase(Configuration["PathBase"]);

I've also had to add an environment variable to the app, so that the /web is configurable as I can't access the X-Original-URI header on app start.

-- Steve
Source: StackOverflow