Request path that contains a hostname results in wrong routing

[chitoku-k]

Description of the problem

Let's say we have the ingress in the last section of this issue. This ingress only specifies that it should route traffic by its hostname; however, when the request path contains a subdomain, it routes to a wrong one as in the following:

OK: example.com goes to nginx-alice

$ curl example.com
nginx-alice-7f9b8cd46d-8rll5

OK: subdomain.example.com goes to nginx-bob

$ curl subdomain.example.com
nginx-bob-848d7b78d9-sv4cv

WRONG: subdomain.example.com/example.com goes to nginx-alice

$ curl subdomain.example.com/example.com
nginx-alice-7f9b8cd46d-8rll5

Expected behavior

example.com goes to nginx-alice

$ curl example.com
nginx-alice-7f9b8cd46d-8rll5

subdomain.example.com goes to nginx-bob

$ curl subdomain.example.com
nginx-bob-848d7b78d9-sv4cv

subdomain.example.com/example.com goes to nginx-bob

$ curl subdomain.example.com/example.ocm
nginx-bob-848d7b78d9-sv4cv

Steps to reproduce the problem

1. Deploy the following manifest to a Kubernetes cluster:
   (It contains two nginx Pods that print each Pod name respectively whatever path it is given)

   ---
   apiVersion: v1
   kind: ConfigMap
   metadata:
     name: nginx-conf
     namespace: default
   data:
     default.conf.template: |
       server {
         listen 80 default;
         listen [::]:80 default;
         server_name _;
         keepalive_timeout 0;
   
         location / {
           add_header Content-Type text/plain;
           return 200 "$BODY\n";
         }
       }
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: nginx-alice
     namespace: default
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: nginx-alice
     template:
       metadata:
         labels:
           app: nginx-alice
       spec:
         containers:
           - name: web
             image: nginx:1.19.7-alpine
             env:
               - name: BODY
                 valueFrom:
                   fieldRef:
                     fieldPath: metadata.name
             volumeMounts:
               - name: nginx-conf
                 mountPath: /etc/nginx/templates
             ports:
               - name: http
                 containerPort: 80
         volumes:
           - name: nginx-conf
             configMap:
               name: nginx-conf
   ---
   apiVersion: v1
   kind: Service
   metadata:
     name: nginx-alice
     namespace: default
   spec:
     ports:
       - name: http
         protocol: TCP
         port: 80
         targetPort: 80
     selector:
       app: nginx-alice
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: nginx-bob
     namespace: default
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: nginx-bob
     template:
       metadata:
         labels:
           app: nginx-bob
       spec:
         containers:
           - name: web
             image: nginx:1.19.7-alpine
             env:
               - name: BODY
                 valueFrom:
                   fieldRef:
                     fieldPath: metadata.name
             volumeMounts:
               - name: nginx-conf
                 mountPath: /etc/nginx/templates
             ports:
               - name: http
                 containerPort: 80
         volumes:
           - name: nginx-conf
             configMap:
               name: nginx-conf
   ---
   apiVersion: v1
   kind: Service
   metadata:
     name: nginx-bob
     namespace: default
   spec:
     ports:
       - name: http
         protocol: TCP
         port: 80
         targetPort: 80
     selector:
       app: nginx-bob

2. Deploy the ingress in the previous section
3. curl to HAProxy

Environment information

HAProxy Ingress version: v0.11 and v0.12 (NOT reproducible in v0.10)

Command-line options:

--configmap=ingress-controller/haproxy-ingress

Global options:

apiVersion: v1
kind: ConfigMap
metadata:
  name: haproxy-ingress
  namespace: ingress-controller
data:
  bind-http: ':80,:::80'

Ingress objects:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress
  namespace: default
spec:
  rules:
    - host: example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: nginx-alice
                port:
                  number: 80
    - host: subdomain.example.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: nginx-bob
                port:
                  number: 80

[jcmoraisjr]

Good catch, thanks for the report. This behavior comes from the way haproxy's dir match type works - it's matching the pattern list with your input without start from the beginning of the string. I'll try a proper fix in the next few days, in the mean time you can work around your configuration changing pathType from Prefix to ImplementationSpecific.

[jcmoraisjr]

v0.12.2 and v0.11.5 were just released and fixes this issue. Closing.