Ingress path redirection appends port

Ingress bazi URL isteklerine container port'u ile redirect etmeye calistigi gibi bir sorunla karsilasabilirsiniz. Ornek olarak biraz daha acmak gerekirse;

$ curl -I http://cafe.example.com/coffee/

HTTP/1.1 200 OK
Date: Mon, 07 Dec 2020 23:47:21 GMT
Content-Type: text/html
Content-Length: 87466
Connection: keep-alive
Last-Modified: Mon, 07 Dec 2020 20:48:36 GMT
ETag: "5fce9524-155aa"
Accept-Ranges: bytes

Yukarida goruldugu "http://cafe.example.com/coffee/" adresine gonderdigimiz istek saglikli sekilde "200" kodunu cevap olarak donuyor. Birde "http://cafe.example.com/coffee" seklinde istekte bulunarak test edelim:

$ curl -I http://cafe.example.com/coffee

HTTP/1.1 301 Moved Permanently
Date: Sun, 07 Dec 2020 23:52:48 GMT
Content-Type: text/html
Content-Length: 169
Connection: keep-alive
Location: http://cafe.example.com:8080/coffee

Bu ornek ise goruldugu gibi "http://hostname:cointainer_port/paths" seklinde container portunu da ekleyerek sayfayi yanlis sekilde redirect etmeye calisiyor ve sayfa ulasilamaz oluyor. Buradaki '8080' portu ingress'in arka tarafindaki nginx container'in yayin yapmakta olan portu.

Sorunun sebebine gelince, bu sorunun ingress ile hic bir alakasi yok. Hem kubernetes/ingress-nginx hem de nginxinc/nginx-ingress ingress controller'larinda nginx konfigurasyonu uzerindeki port_in_redirect degeri default olarak 'off' olarak. Fakat arka tarafta calisan nginx container uzerindeki bu konfigurasyonu 'on' yapilmissa bu durumla karsilasabilirsiniz. Bunu nginx.conf uzerinde 'port_in_redirect off;' seklinde kapatarak yasanmasini engelleyebilirsiniz.

Asagidaki sekilde nginx.conf'u configmap'e ekleyerek nginx pod'un bu configmap'i kullanmasini saglayarak deployment yapabilirsiniz.

apiVersion: v1
kind: ConfigMap
metadata:
  name: nginx-conf
data:
  nginx.conf: |
    worker_processes  1;

    error_log  /var/log/nginx/error.log warn;
    pid        /tmp/nginx.pid;


    events {
        worker_connections  1024;
    }


    http {
        proxy_temp_path /tmp/proxy_temp;
        client_body_temp_path /tmp/client_temp;
        fastcgi_temp_path /tmp/fastcgi_temp;
        uwsgi_temp_path /tmp/uwsgi_temp;
        scgi_temp_path /tmp/scgi_temp;

        include       /etc/nginx/mime.types;
        default_type  application/octet-stream;

        log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                          '$status $body_bytes_sent "$http_referer" '
                          '"$http_user_agent" "$http_x_forwarded_for"';

        access_log  /var/log/nginx/access.log  main;

        sendfile        on;
        #tcp_nopush     on;

        port_in_redirect off;

        keepalive_timeout  65;

        #gzip  on;

        include /etc/nginx/conf.d/*.conf;
    }

---

apiVersion: apps/v1
kind: Deployment
metadata:
  name: coffee
spec:
  replicas: 3
  selector:
    matchLabels:
      app: coffee
  template:
    metadata:
      labels:
        app: coffee
    spec:
      containers:
      - name: www
        image: nginxinc/nginx-unprivileged
        ports:
        - containerPort: 8080
        volumeMounts:
        - name: nginx-conf
          mountPath: /etc/nginx/nginx.conf
          subPath: nginx.conf
          readOnly: true

---

---
apiVersion: v1
kind: Service
metadata:
  name: coffee-svc
spec:
  ports:
  - port: 80
    targetPort: 8080
    protocol: TCP
    name: http
  selector:
    app: coffee