6eecefd3da
The annotation for the controller class was inconsistent in the example. From my best understanding, I have tried to fix the inconsistency. Also, removed an incomplete sentence. And made one sentence more clear by breaking it up.
113 lines
3.9 KiB
Markdown
113 lines
3.9 KiB
Markdown
# Multiple Ingress controllers
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By default, deploying multiple Ingress controllers (e.g., `ingress-nginx` & `gce`) will result in all controllers simultaneously racing to update Ingress status fields in confusing ways.
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To fix this problem, use [IngressClasses](https://kubernetes.io/docs/concepts/services-networking/ingress/#ingress-class). The `kubernetes.io/ingress.class` annotation is deprecated from kubernetes v1.22+.
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## Using IngressClasses
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If all ingress controllers respect IngressClasses (e.g. multiple instances of ingress-nginx v1.0), you can deploy two Ingress controllers by granting them control over two different IngressClasses, then selecting one of the two IngressClasses with `ingressClassName`.
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First, ensure the `--controller-class=` and `--ingress-class` are set to something different on each ingress controller:
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```yaml
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# ingress-nginx Deployment/Statfulset
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spec:
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template:
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spec:
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containers:
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- name: ingress-nginx-internal-controller
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args:
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- /nginx-ingress-controller
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- '--controller-class=k8s.io/internal-ingress-nginx'
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- '--ingress-class=k8s.io/internal-nginx'
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...
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```
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Then use the same value in the IngressClass:
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```yaml
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# ingress-nginx IngressClass
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apiVersion: networking.k8s.io/v1
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kind: IngressClass
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metadata:
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name: internal-nginx
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spec:
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controller: k8s.io/internal-ingress-nginx
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...
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```
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And refer to that IngressClass in your Ingress:
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```yaml
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apiVersion: networking.k8s.io/v1
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kind: Ingress
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metadata:
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name: my-ingress
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spec:
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ingressClassName: internal-nginx
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...
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```
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or if installing with Helm:
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```yaml
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controller:
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ingressClassResource:
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name: internal-nginx # default: nginx
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enabled: true
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default: false
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controllerValue: "k8s.io/internal-ingress-nginx" # default: k8s.io/ingress-nginx
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```
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!!! important
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When running multiple ingress-nginx controllers, it will only process an unset class annotation if one of the controllers uses the default
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`--controller-class` value (see `IsValid` method in `internal/ingress/annotations/class/main.go`), otherwise the class annotation becomes required.
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If `--controller-class` is set to the default value of `k8s.io/ingress-nginx`, the controller will monitor Ingresses with no class annotation *and* Ingresses with annotation class set to `nginx`. Use a non-default value for `--controller-class`, to ensure that the controller only satisfied the specific class of Ingresses.
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## Using the kubernetes.io/ingress.class annotation (in deprecation)
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If you're running multiple ingress controllers where one or more do not support IngressClasses, you must specify the annotation `kubernetes.io/ingress.class: "nginx"` in all ingresses that you would like ingress-nginx to claim.
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For instance,
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```yaml
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metadata:
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name: foo
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annotations:
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kubernetes.io/ingress.class: "gce"
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```
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will target the GCE controller, forcing the Ingress-NGINX controller to ignore it, while an annotation like:
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```yaml
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metadata:
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name: foo
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annotations:
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kubernetes.io/ingress.class: "nginx"
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```
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will target the Ingress-NGINX controller, forcing the GCE controller to ignore it.
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You can change the value "nginx" to something else by setting the `--ingress-class` flag:
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```yaml
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spec:
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template:
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spec:
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containers:
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- name: ingress-nginx-internal-controller
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args:
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- /nginx-ingress-controller
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- --ingress-class=internal-nginx
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```
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then setting the corresponding `kubernetes.io/ingress.class: "internal-nginx"` annotation on your Ingresses.
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To reiterate, setting the annotation to any value which does not match a valid ingress class will force the NGINX Ingress controller to ignore your Ingress.
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If you are only running a single NGINX ingress controller, this can be achieved by setting the annotation to any value except "nginx" or an empty string.
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Do this if you wish to use one of the other Ingress controllers at the same time as the NGINX controller.
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