Using ingress to access external service with contextPath

Question

I have a Wildfly with a set of applications, not running in the kubernetes cluster. Lets say one is http://wildfly-external/FOO/

From within the cluster, I want that my cluster applications can reach FOO without knowing the contextPath on the wildfly.

Our approach was to generate a Endpint, Service and an Ingress for this Service containing the path

service.yaml

apiVersion: v1
kind: Service
metadata:
    annotations:
        meta.helm.sh/release-name: dns
        meta.helm.sh/release-namespace: test
    creationTimestamp: "2020-08-31T17:32:08Z"
    labels:
        app.kubernetes.io/instance: dns
        app.kubernetes.io/managed-by: Helm
        app.kubernetes.io/name: foo
        helm.sh/chart: dns-1.0.0-snapshot
    name: foo
    namespace: test
    resourceVersion: "151848872"
    selfLink: /api/v1/namespaces/test/services/foo
    uid: e5607cd4-ebaf-11ea-9f17-005056a7cff9
spec:
    clusterIP: 10.200.149.146
    ports:
        - name: foo
          port: 80
          protocol: TCP
          targetPort: 13000
    sessionAffinity: None
    type: ClusterIP
status:
    loadBalancer: {}

ingress.yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
    annotations:
        meta.helm.sh/release-name: dns
        meta.helm.sh/release-namespace: test
    creationTimestamp: "2020-08-31T17:32:08Z"
    generation: 1
    labels:
        app.kubernetes.io/instance: dns
        app.kubernetes.io/managed-by: Helm
        app.kubernetes.io/name: foo
        helm.sh/chart: dns-1.0.0-snapshot
    name: foo
    namespace: test
    resourceVersion: "151848901"
    selfLink: /apis/extensions/v1beta1/namespaces/test/ingresses/foo
    uid: e56cc8c9-ebaf-11ea-9f17-005056a7cff9
spec:
    rules:
        - http:
              paths:
                  - backend:
                        serviceName: foo
                        servicePort: http
                    path: /FOO
status:
    loadBalancer:
        ingress:
            - ip: 10.6.1.1

Unfortunately when curl http//foo/ inside a pod, I reach the wildfly start page at http://wildfly, not the application at http://wildfly/FOO. This looks like I access the service through http://foo/ and not going through the ingress.

Is it possible to do, what I want to do? Any hints?

Answer 1

From my view, the ingress is on top of service. The sequence is browser->ingress(application load balance)->service. Now the url http//foo/ is to access service instead of ingress. You can use ingress to mapping context to service with ingress rewrite, but you need visit url with full host name of ingress. Thanks,