Merge Ingress Controller

Merge Ingress Controller combines multiple ingress resources into a new one.

Motivation

Different ingress controllers behave differently when creating services/load balancers satisfying the ingress resources of the managed class. Some create single service/LB for all ingress resources, some merge resources according to hosts or TLS certificates, other create separate service/LB per ingress resource.

E.g. AWS ALB Ingress Controller creates a new load balancer for each ingress resource. This can become quite costly. There is an issue to support reusing ALBs across ingress resources, however, it won't be implemented anytime soon.

Merge Ingress Controller allows you to create ingress resources that will be combined together to create a new ingress resource that will be managed by different controller.

Setup

Install via Helm:

helm install --namespace kube-system --name ingress-merge ./helm

Example

Create multiple ingresses & one config map that will provide parameters for the result ingress:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: foo-ingress
  annotations:
    kubernetes.io/ingress.class: merge
    merge.ingress.kubernetes.io/config: merged-ingress
spec:
  rules:
  - host: foo.example.com
    http:
      paths:
      - path: /
        backend:
          serviceName: foo-svc
          servicePort: 80

---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: bar-ingress
  annotations:
    kubernetes.io/ingress.class: merge
    merge.ingress.kubernetes.io/config: merged-ingress
spec:
  rules:
  - host: bar.example.com
    http:
      paths:
      - path: /
        backend:
          serviceName: bar-svc
          servicePort: 80

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: merged-ingress
data:
  annotations: |
    kubernetes.io/ingress.class: other

Merge Ingress Controller will create new ingress resource named by the config map with rules combined together:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: merged-ingress
  annotations:
    kubernetes.io/ingress.class: other
spec:
  rules:
  - host: bar.example.com
    http:
      paths:
      - path: /
        backend:
          serviceName: bar-svc
          servicePort: 80

  - host: foo.example.com
    http:
      paths:
      - path: /
        backend:
          serviceName: foo-svc
          servicePort: 80

Annotations

Configuration keys

License

Licensed under MIT license. See LICENSE file.