Advanced NGINX ingress controller and ingress configurations with the application routing add-on

Article
01/29/2024

The application routing add-on supports two ways to configure ingress controllers and ingress objects:

Configuration of the NGINX ingress controller such as creating multiple controllers, configuring private load balancers, and setting static IP addresses.
Configuration per ingress resource through annotations.

Prerequisites

An AKS cluster with the application routing add-on.

Connect to your AKS cluster

To connect to the Kubernetes cluster from your local computer, you use kubectl, the Kubernetes command-line client. You can install it locally using the az aks install-cli command. If you use the Azure Cloud Shell, kubectl is already installed.

Configure kubectl to connect to your Kubernetes cluster using the az aks get-credentials command.

az aks get-credentials -g <ResourceGroupName> -n <ClusterName>

Configuration of the NGINX ingress controller

The application routing add-on uses a Kubernetes custom resource definition (CRD) called NginxIngressController to configure NGINX ingress controllers. You can create more ingress controllers or modify existing configuration.

NginxIngressController CRD has a loadBalancerAnnotations field to control the behavior of the NGINX ingress controller's service by setting load balancer annotations.

The default NGINX ingress controller

When you enable the application routing add-on with NGINX, it creates an ingress controller called default in the app-routing-namespace configured with a public facing Azure load balancer. That ingress controller uses an ingress class name of webapprouting.kubernetes.azure.com.

Create another public facing NGINX ingress controller

To create another NGINX ingress controller with a public facing Azure Load Balancer:

Copy the following YAML manifest into a new file named nginx-public-controller.yaml and save the file to your local computer.

apiVersion: approuting.kubernetes.azure.com/v1alpha1
kind: NginxIngressController
metadata:
  name: nginx-public
spec:
  ingressClassName: nginx-public
  controllerNamePrefix: nginx-public

Create the NGINX ingress controller resources using the kubectl apply command.
```
kubectl apply -f nginx-public-controller.yaml
```
The following example output shows the created resource:
```
nginxingresscontroller.approuting.kubernetes.azure.com/nginx-public created
```

Create an internal NGINX ingress controller with a private IP address

To create an NGINX ingress controller with an internal facing Azure Load Balancer with a private IP address:

Copy the following YAML manifest into a new file named nginx-internal-controller.yaml and save the file to your local computer.

apiVersion: approuting.kubernetes.azure.com/v1alpha1
kind: NginxIngressController
metadata:
  name: nginx-internal
spec:
  ingressClassName: nginx-internal
  controllerNamePrefix: nginx-internal
  loadBalancerAnnotations: 
    service.beta.kubernetes.io/azure-load-balancer-internal: "true"

Create the NGINX ingress controller resources using the kubectl apply command.
```
kubectl apply -f nginx-internal-controller.yaml
```
The following example output shows the created resource:
```
nginxingresscontroller.approuting.kubernetes.azure.com/nginx-internal created
```

Create an NGINX ingress controller with a static IP address

To create an NGINX ingress controller with a static IP address on the Azure Load Balancer:

Create an Azure resource group using the az group create command.

az group create --name myNetworkResourceGroup --location eastus

Create a static public IP address using the az network public ip create command.
```
az network public-ip create \
    --resource-group myNetworkResourceGroup \
    --name myIngressPublicIP \
    --sku Standard \
    --allocation-method static
```
Note

If you're using a Basic SKU load balancer in your AKS cluster, use Basic for the --sku parameter when defining a public IP. Only Basic SKU IPs work with the Basic SKU load balancer and only Standard SKU IPs work with Standard SKU load balancers.

Ensure the cluster identity used by the AKS cluster has delegated permissions to the public IP's resource group using the [az role assignment create][az-role-assignment-create] command.

Note

Update <ClusterName> and <ClusterResourceGroup> with your AKS cluster's name and resource group name.

CLIENT_ID=$(az aks show --name <ClusterName> --resource-group <ClusterResourceGroup> --query identity.principalId -o tsv)
RG_SCOPE=$(az group show --name myNetworkResourceGroup --query id -o tsv)
az role assignment create \
    --assignee ${CLIENT_ID} \
    --role "Network Contributor" \
    --scope ${RG_SCOPE}

Copy the following YAML manifest into a new file named nginx-staticip-controller.yaml and save the file to your local computer.

Note

You can either use service.beta.kubernetes.io/azure-pip-name for public IP name, or use service.beta.kubernetes.io/azure-load-balancer-ipv4 for an IPv4 address and service.beta.kubernetes.io/azure-load-balancer-ipv6 for an IPv6 address, as shown in the example YAML. Adding the service.beta.kubernetes.io/azure-pip-name annotation ensures the most efficient LoadBalancer creation and is highly recommended to avoid potential throttling.
```
apiVersion: approuting.kubernetes.azure.com/v1alpha1
kind: NginxIngressController
metadata:
  name: nginx-static
spec:
  ingressClassName: nginx-static
  controllerNamePrefix: nginx-static
  loadBalancerAnnotations: 
    service.beta.kubernetes.io/azure-pip-name: "myIngressPublicIP"
    service.beta.kubernetes.io/azure-load-balancer-resource-group: "myNetworkResourceGroup"
```
Create the NGINX ingress controller resources using the kubectl apply command.
```
kubectl apply -f nginx-staticip-controller.yaml
```
The following example output shows the created resource:
```
nginxingresscontroller.approuting.kubernetes.azure.com/nginx-static created
```

Verify the ingress controller was created

You can verify the status of the NGINX ingress controller using the kubectl get nginxingresscontroller command.

Note

Update <IngressControllerName> with name you used when creating the `NginxIngressController``.

kubectl get nginxingresscontroller -n <IngressControllerName>

The following example output shows the created resource. It may take a few minutes for the controller to be available:

NAME           INGRESSCLASS   CONTROLLERNAMEPREFIX   AVAILABLE
nginx-public   nginx-public   nginx                  True

You can also view the conditions to troubleshoot any issues:

kubectl get nginxingresscontroller -n <IngressControllerName> -o jsonpath='{range .items[*].status.conditions[*]}{.lastTransitionTime}{"\t"}{.status}{"\t"}{.type}{"\t"}{.message}{"\n"}{end}'

The following example output shows the conditions of a healthy ingress controller:

2023-11-29T19:59:24Z    True    IngressClassReady       Ingress Class is up-to-date
2023-11-29T19:59:50Z    True    Available               Controller Deployment has minimum availability and IngressClass is up-to-date
2023-11-29T19:59:50Z    True    ControllerAvailable     Controller Deployment is available
2023-11-29T19:59:25Z    True    Progressing             Controller Deployment has successfully progressed

Use the ingress controller in an ingress

Copy the following YAML manifest into a new file named ingress.yaml and save the file to your local computer.

Note

Update <Hostname> with your DNS host name. The <IngressClassName> is the one you defined when creating the NginxIngressController.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: aks-helloworld
  namespace: hello-web-app-routing
spec:
  ingressClassName: <IngressClassName>
  rules:
  - host: <Hostname>
    http:
      paths:
      - backend:
          service:
            name: aks-helloworld
            port:
              number: 80
        path: /
        pathType: Prefix

Create the cluster resources using the kubectl apply command.
```
kubectl apply -f ingress.yaml -n hello-web-app-routing
```
The following example output shows the created resource:
```
ingress.networking.k8s.io/aks-helloworld created
```

Verify the managed Ingress was created

You can verify the managed Ingress was created using the kubectl get ingress command.

kubectl get ingress -n hello-web-app-routing

The following example output shows the created managed Ingress. The ingress class, host and IP address may be different:

NAME             CLASS                                HOSTS               ADDRESS       PORTS     AGE
aks-helloworld   webapprouting.kubernetes.azure.com   myapp.contoso.com   20.51.92.19   80, 443   4m

Clean up of ingress controllers

You can remove the NGINX ingress controller using the kubectl delete nginxingresscontroller command.

Note

Update <IngressControllerName> with name you used when creating the NginxIngressController.

kubectl delete nginxingresscontroller -n <IngressControllerName>

Configuration per ingress resource through annotations

The NGINX ingress controller supports adding annotations to specific Ingress objects to customize their behavior.

You can annotate the ingress object by adding the respective annotation in the metadata.annotations field.

Note

Annotation keys and values can only be strings. Other types, such as boolean or numeric values must be quoted, i.e. "true", "false", "100".

Here are some examples annotations for common configurations. Review the NGINX ingress annotations documentation for a full list.

Custom max body size

For NGINX, a 413 error is returned to the client when the size in a request exceeds the maximum allowed size of the client request body. To override the default value, use the annotation:

nginx.ingress.kubernetes.io/proxy-body-size: 4m

Here's an example ingress configuration using this annotation:

Note

Update <Hostname> with your DNS host name. The <IngressClassName> is the one you defined when creating the NginxIngressController.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: aks-helloworld
  namespace: hello-web-app-routing
  annotations:
    nginx.ingress.kubernetes.io/proxy-body-size: 4m
spec:
  ingressClassName: <IngressClassName>
  rules:
  - host: <Hostname>
    http:
      paths:
      - backend:
          service:
            name: aks-helloworld
            port:
              number: 80
        path: /
        pathType: Prefix

Custom connection timeout

You can change the timeout that the NGINX ingress controller waits to close a connection with your workload. All timeout values are unitless and in seconds. To override the default timeout, use the following annotation to set a valid 120-seconds proxy read timeout:

nginx.ingress.kubernetes.io/proxy-read-timeout: "120"

Review custom timeouts for other configuration options.

Here's an example ingress configuration using this annotation:

Note

Update <Hostname> with your DNS host name. The <IngressClassName> is the one you defined when creating the NginxIngressController.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: aks-helloworld
  namespace: hello-web-app-routing
  annotations:
    nginx.ingress.kubernetes.io/proxy-read-timeout: "120"
spec:
  ingressClassName: <IngressClassName>
  rules:
  - host: <Hostname>
    http:
      paths:
      - backend:
          service:
            name: aks-helloworld
            port:
              number: 80
        path: /
        pathType: Prefix

Backend protocol

By default the NGINX ingress controller uses HTTP to reach the services. To configure alternative backend protocols such as HTTPS or GRPC, use the annotation:

nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"

nginx.ingress.kubernetes.io/backend-protocol: "GRPC"

Review backend protocols for other configuration options.

Here's an example ingress configuration using this annotation:

Note

Update <Hostname> with your DNS host name. The <IngressClassName> is the one you defined when creating the NginxIngressController.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: aks-helloworld
  namespace: hello-web-app-routing
  annotations:
    nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
spec:
  ingressClassName: <IngressClassName>
  rules:
  - host: <Hostname>
    http:
      paths:
      - backend:
          service:
            name: aks-helloworld
            port:
              number: 80
        path: /
        pathType: Prefix

To enable Cross-Origin Resource Sharing (CORS) in an Ingress rule, use the annotation:

nginx.ingress.kubernetes.io/enable-cors: "true"

Review enable CORS for other configuration options.

Here's an example ingress configuration using this annotation:

Note

Update <Hostname> with your DNS host name. The <IngressClassName> is the one you defined when creating the NginxIngressController.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: aks-helloworld
  namespace: hello-web-app-routing
  annotations:
    nginx.ingress.kubernetes.io/enable-cors: "true"
spec:
  ingressClassName: <IngressClassName>
  rules:
  - host: <Hostname>
    http:
      paths:
      - backend:
          service:
            name: aks-helloworld
            port:
              number: 80
        path: /
        pathType: Prefix

Disable SSL redirect

By default the controller redirects (308) to HTTPS if TLS is enabled for an ingress. To disable this feature for specific ingress resources, use the annotation:

nginx.ingress.kubernetes.io/ssl-redirect: "false"

Review server-side HTTPS enforcement through redirect for other configuration options.

Here's an example ingress configuration using this annotation:

Note

Update <Hostname> with your DNS host name. The <IngressClassName> is the one you defined when creating the NginxIngressController.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: aks-helloworld
  namespace: hello-web-app-routing
  annotations:
    nginx.ingress.kubernetes.io/ssl-redirect: "false"
spec:
  ingressClassName: <IngressClassName>
  rules:
  - host: <Hostname>
    http:
      paths:
      - backend:
          service:
            name: aks-helloworld
            port:
              number: 80
        path: /
        pathType: Prefix

URL rewriting

In some scenarios, the exposed URL in the backend service differs from the specified path in the Ingress rule. Without a rewrite any request returns 404. This is particularly useful with path based routing where you can serve two different web applications under the same domain. You can set path expected by the service using the annotation:

nginx.ingress.kubernetes.io/rewrite-target": /$2

Here's an example ingress configuration using this annotation:

Note

Update <Hostname> with your DNS host name. The <IngressClassName> is the one you defined when creating the NginxIngressController.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: aks-helloworld
  namespace: hello-web-app-routing
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /$2
    nginx.ingress.kubernetes.io/use-regex: "true"
spec:
  ingressClassName: <IngressClassName>
  rules:
  - host: <Hostname>
    http:
      paths:
      - path: /app-one(/|$)(.*)
        pathType: Prefix 
        backend:
          service:
            name: app-one
            port:
              number: 80
      - path: /app-two(/|$)(.*)
        pathType: Prefix 
        backend:
          service:
            name: app-two
            port:
              number: 80

Next steps

Learn about monitoring the ingress-nginx controller metrics included with the application routing add-on with with Prometheus in Grafana as part of analyzing the performance and usage of your application.

Advanced NGINX ingress controller and ingress configurations with the application routing add-on

Prerequisites

Connect to your AKS cluster

Configuration of the NGINX ingress controller

The default NGINX ingress controller

Create another public facing NGINX ingress controller

Create an internal NGINX ingress controller with a private IP address

Create an NGINX ingress controller with a static IP address

Verify the ingress controller was created

Use the ingress controller in an ingress

Verify the managed Ingress was created

Clean up of ingress controllers

Configuration per ingress resource through annotations

Custom max body size

Custom connection timeout

Backend protocol

Disable SSL redirect

URL rewriting

Next steps

Feedback

Additional resources