kubernetes ingress backend and frontend routing

Question

I have an application backend and frontend and I want to separate the traffic using prefix /api I usually do this with Nginx and docker-compose using this configuration :

upstream server {
    server backend:6969;
}


server {
    listen 80;
        server_name _;

        root   /usr/share/nginx/html;
    index  index.html index.htm;
        include /etc/nginx/mime.types;

        gzip on;
        gzip_min_length 1000;
        gzip_proxied expired no-cache no-store private auth;
        gzip_types text/plain text/css application/json application/javascript application/x-javascript text/xml application/xml application/xml+rss text/javascript;

    location /api {
        proxy_pass http://server;
        proxy_http_version 1.1;
            proxy_set_header Host               $host;
            proxy_set_header X-Real-IP          $remote_addr;
            proxy_set_header X-Forwarded-For    $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto  $scheme;
    }

    location / {
        try_files $uri $uri/ /index.html;
    }

}

and now I want to use Kubernetes ingress to do the same job, I used Kubeadm in my cluster and https://haproxy-ingress.github.io/ as ingress controller

this is my ingress yaml:

apiVersion: networking.k8s.io/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: haproxy
  name: ingress
  namespace: lab
spec:
  backend:
    serviceName: frontend
    servicePort: 80
  rules:
    - http:
        paths:
          - backend:
              serviceName: backend
              servicePort: 6969
            path: /api

this all the resources that I deployed

NAME                            READY   STATUS    RESTARTS   AGE
pod/backend-5c8c6c75bf-t4n9r    1/1     Running   0          39m
pod/frontend-75d86fb77d-6gtfs   1/1     Running   0          10m
pod/mysql-0                     1/1     Running   0          30h

NAME               TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)    AGE
service/backend    ClusterIP   10.111.235.245   <none>        6969/TCP   150m
service/frontend   ClusterIP   10.98.38.60      <none>        80/TCP     9m56s
service/mysql      ClusterIP   10.107.88.14     <none>        3306/TCP   4d23h

NAME                       READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/backend    1/1     1            1           39m
deployment.apps/frontend   1/1     1            1           10m

NAME                                  DESIRED   CURRENT   READY   AGE
replicaset.apps/backend-5c8c6c75bf    1         1         1       39m
replicaset.apps/frontend-75d86fb77d   1         1         1       10m

NAME                     READY   AGE
statefulset.apps/mysql   1/1     30h

Why it doesn't work? can you please check with me?

Answer 1

See the solution in this question. It will probably require you to introduce some minor tweaks in your k8s/docker/backend configuration (like specifying URL prefix) but it is the easiest solution I can imagine. I unsuccessfully tried Nginx-Ingress "rewrite" annotations to make the job done for me but looks like it is hard for Nginx-Ingress to emulate full-fledged Nginx configs.

The other solution can be to adapt the official Kubernetes tutorial on multi-service management with LoadBalancer.