Merge Ingress Controller combines multiple ingress resources into a new one.
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.
Install via Helm:
helm install --namespace kube-system --name ingress-merge ./helm
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
| Annotation | Default Value | Description | Example |
|---|---|---|---|
kubernetes.io/ingress.class |
Use merge for this controller to take over. |
kubernetes.io/ingress.class: merge |
|
merge.ingress.kubernetes.io/config |
Name of the ConfigMap resource that will be used to merge this ingress with others. Because ingresses do not support to reference services across namespaces, neither does this reference. All ingresses to be merged, the config map & the result ingress use the same namespace. |
merge.ingress.kubernetes.io/config: merged-ingress |
|
merge.ingress.kubernetes.io/priority |
0 |
Rules from ingresses with higher priority come in the result ingress rules first. | merge.ingress.kubernetes.io/priority: 10 |
merge.ingress.kubernetes.io/result |
Marks ingress created by the controller. If all source ingress resources are deleted, this ingress is deleted as well. | merge.ingress.kubernetes.io/result: "true" |
| Key | Default Value | Description | Example |
|---|---|---|---|
name |
name of the ConfigMap |
Name of the result ingress resource. | name: my-merged-ingress |
labels |
YAML/JSON-serialized labels to be applied to the result ingress. | labels: '{"app": "loadbalancer", "env": "prod"}' |
|
annotations |
{"merge.ingress.kubernetes.io/result":"true"} |
YAML/JSON-serialized labels to be applied to the result ingress. merge.ingress.kubernetes.io/result with value true will be always added to the annotations. |
annotations: '{"kubernetes.io/ingress.class": "alb"} |
backend |
Default backend for the result ingress (spec.backend). Source ingresses must not specify default backend (such ingresses won't be merged). |
backend: '{"serviceName": "default-backend-svc", "servicePort": 80} |
Licensed under MIT license. See LICENSE file.