How to map different services to different paths with the same host within Ingress for AWS ALB?

Question

I have two services that I am trying to deploy through a Helm chart:

1. Frontend Service(which is accessible through the host, and uses NodePort)
2. Backend Service(which is only accessible inside the cluster, and uses ClusterIP)

I am facing an issue with the Ingress of the deployment I am using AWS ALB where it throws a 404 Not Found error when accessing the Frontend Service.

ingress.yaml:

{{- if .Values.ingress.enabled -}}
{{- $fullName := include "metaflow-ui.fullname" . -}}
{{- $svcPort := .Values.service.port -}}
{{- $fullNameStatic := include "metaflow-ui.fullname-static" . -}}
{{- $svcPortStatic := .Values.serviceStatic.port -}}
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  namespace: metaflow-ui
  name: {{ $fullName }}
  labels:
    {{- include "metaflow-ui.labels" . | nindent 4 }}
  {{- with .Values.ingress.annotations }}
  annotations:
    {{- toYaml . | nindent 4 }}
    alb.ingress.kubernetes.io/healthcheck-path: "/api"
    alb.ingress.kubernetes.io/success-codes: "200"
  {{- end }}
spec:
  rules:
  - host: {{ .Values.externalDNS }}
    http:
      paths:
      - path: /api
        pathType: Prefix
        backend:
          serviceName: {{ $fullName }}
          servicePort: {{ $svcPort }}
---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  namespace: metaflow-ui
  name: {{ $fullName }}
  labels:
    {{- include "metaflow-ui.labels" . | nindent 4 }}
  {{- with .Values.ingress.annotations }}
  annotations:
    {{- toYaml . | nindent 4 }}
    alb.ingress.kubernetes.io/healthcheck-path: "/"
    alb.ingress.kubernetes.io/success-codes: "200"
  {{- end }}
spec:
  rules:
  - host: {{ .Values.externalDNS }}
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          serviceName: {{ $fullNameStatic }}
          servicePort: {{ $svcPortStatic }}
---
{{ end }}

These are the annotations for Ingress under values.yaml:

ingress:
  enabled: true
  className: ""
  annotations:
    kubernetes.io/ingress.class: alb
    alb.ingress.kubernetes.io/scheme: internal
    alb.ingress.kubernetes.io/group.name: metaflow-ui
    alb.ingress.kubernetes.io/security-groups: # removed
    alb.ingress.kubernetes.io/listen-ports:  '[{"HTTP": 80}, {"HTTPS":443}]'
    alb.ingress.kubernetes.io/certificate-arn: # removed
    alb.ingress.kubernetes.io/actions.ssl-redirect: '{"Type": "redirect", "RedirectConfig": { "Protocol": "HTTPS", "Port": "443", "StatusCode": "HTTP_301"}}'

I read that attaching a group.name was the fix to enable a single AWS ALB to be shared across multiple Ingress but it didn't fix the issue. If I were to remove the second ingress the entire site is deployed(but without the backend service).

EDIT:

I found this article that goes over this exact application, How do I achieve path-based routing on an Application Load Balancer?, will try it out.

Answer 1

I managed to get it to work using the following Ingress set up. Instead of having a single Ingress per service I ended up using a single Ingress but kept the group.name.

{{- if .Values.ingress.enabled -}}
{{- $fullName := include "metaflow-ui.fullname" . -}}
{{- $svcPort := .Values.service.port -}}
{{- $fullNameStatic := include "metaflow-ui.fullname-static" . -}}
{{- $svcPortStatic := .Values.serviceStatic.port -}}
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: {{ $fullName }}
  labels:
    {{- include "metaflow-ui.labels" . | nindent 4 }}
  {{- with .Values.ingress.annotations }}
  annotations:
    {{- toYaml . | nindent 4 }}
    alb.ingress.kubernetes.io/healthcheck-path: "/"
    alb.ingress.kubernetes.io/success-codes: "200"
  {{- end }}
spec:
  rules:
  - host: {{ .Values.externalDNS }}
    http:
      paths:
      - path: /api
        pathType: Prefix
        backend:
          service:
            name: {{ $fullName }}
            port:
              number: {{ $svcPort }}
      - path: /
        pathType: Prefix
        backend:
          service:
            name: {{ $fullNameStatic }}
            port:
              number: {{ $svcPortStatic }}
      - path: /
        pathType: Prefix
        backend:
          service:
            name: ssl-redirect
            port:
              name: use-annotation
      - path: /static
        pathType: Prefix
        backend:
          service:
            name: {{ $fullNameStatic }}
            port:
              number: {{ $svcPortStatic }}
{{ end }}