Troubleshoot common questions or issues with Ingress Controller

Test with a simple Kubernetes app

The following steps assume:

You have an AKS cluster, with Advanced Networking enabled
AGIC has been installed on the AKS cluster
You already have an Application Gateway on a VNET shared with your AKS cluster

To verify that the Application Gateway + AKS + AGIC installation is set up correctly, deploy the simplest possible app:

cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: Pod
metadata:
  name: test-agic-app-pod
  labels:
    app: test-agic-app
spec:
  containers:
  - image: "mcr.microsoft.com/dotnet/samples:aspnetapp"
    name: aspnetapp-image
    ports:
    - containerPort: 80
      protocol: TCP
---
apiVersion: v1
kind: Service
metadata:
  name: test-agic-app-service
spec:
  selector:
    app: test-agic-app
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
---
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: test-agic-app-ingress
  annotations:
    kubernetes.io/ingress.class: azure/application-gateway
spec:
  #ingressClassName: azure-application-gateway # according to the AGIC setup guide, annotations are the approach to set the class
  rules:
    - host: test.agic.contoso.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              name: test-agic-app-service
              port:
                number: 80
EOF

Copy and paste all lines at once from the previous script. Verify that the entire command is copied - starting with cat and including the last EOF.

After a successful deployment of the app your AKS cluster has a new Pod, Service, and Ingress.

Get the list of pods: kubectl get pods -o wide. We expect for a pod named test-agic-app-pod to have been created with an IP address. This address must be within the VNET of the Application Gateway, which is used with AKS.

Get the list of services: kubectl get services -o wide. We expect to see a service named test-agic-app-service.

Get the list of the ingresses: kubectl get ingress. We expect an Ingress resource named test-agic-app-ingress to have been created. The resource has a host name test.agic.contoso.com.

One of the pods is AGIC. kubectl get pods shows a list of pods, one of which begins with 'ingress-azure.' Get all logs of that pod with kubectl logs <name-of-ingress-controller-pod> to verify that we've had a successful deployment. A successful deployment would have added the following lines to the log:

I0927 22:34:51.281437       1 process.go:156] Applied Application Gateway config in 20.461335266s
I0927 22:34:51.281585       1 process.go:165] cache: Updated with latest applied config.
I0927 22:34:51.282342       1 process.go:171] END AppGateway deployment

Alternatively, we can retrieve only the lines indicating successful Application Gateway configuration with kubectl logs <ingress-azure-....> | grep 'Applied App Gateway config in', where <ingress-azure....> should be the exact name of the AGIC pod.

Application Gateway has the following configuration applied:

Listener:
Routing Rule:
Backend Pool:
- There's one IP address in the backend address pool and it matches the IP address of the Pod we observed earlier with kubectl get pods -o wide

Finally we can use the cURL command to establish an HTTP connection to the newly deployed app:

Use kubectl get ingress to get the Public IP address of Application Gateway
Use curl -I -H 'test.agic.contoso.com' <public-ip-address-from-previous-command>

A result of HTTP/1.1 200 OK indicates that the Application Gateway + AKS + AGIC system is working as expected.

Inspect Kubernetes Installation

Pods, Services, Ingress

Application Gateway Ingress Controller (AGIC) continuously monitors the following Kubernetes resources: Deployment or Pod, Service, Ingress

The following conditions must be in place for AGIC to function as expected:

AKS must have one or more healthy pods. Verify this configuration with kubectl get pods -o wide --show-labels If you have a Pod with an apsnetapp, your output may look like this:

delyan@Azure:~$ kubectl get pods -o wide --show-labels

NAME                   READY   STATUS    RESTARTS   AGE   IP          NODE                       NOMINATED NODE   READINESS GATES   LABELS
aspnetapp              1/1     Running   0          17h   10.0.0.6    aks-agentpool-35064155-1   <none>           <none>            app=aspnetapp

One or more services, referencing these pods via matching selector labels. Verify this configuration with kubectl get services -o wide

delyan@Azure:~$ kubectl get services -o wide --show-labels

NAME                TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)   AGE   SELECTOR        LABELS
aspnetapp           ClusterIP   10.2.63.254    <none>        80/TCP    17h   app=aspnetapp   <none>

Ingress, annotated with kubernetes.io/ingress.class: azure/application-gateway, referencing the previous service. Verify this configuration with kubectl get ingress -o wide --show-labels
```
delyan@Azure:~$ kubectl get ingress -o wide --show-labels

NAME        HOSTS   ADDRESS   PORTS   AGE   LABELS
aspnetapp   *                 80      17h   <none>
```

View annotations of the previous ingress: kubectl get ingress aspnetapp -o yaml (substitute aspnetapp with the name of your ingress)

delyan@Azure:~$ kubectl get ingress aspnetapp -o yaml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: azure/application-gateway
  name: aspnetapp
spec:
  backend:
    serviceName: aspnetapp
    servicePort: 80

The ingress resource must be annotated with kubernetes.io/ingress.class: azure/application-gateway.

Verify Observed Namespace

Get the existing namespaces in Kubernetes cluster. What namespace is your app running in? Is AGIC watching that namespace? Refer to the Multiple Namespace Support documentation on how to properly configure observed namespaces.
```
# What namespaces exist on your cluster
kubectl get namespaces

# What pods are currently running
kubectl get pods --all-namespaces -o wide
```
The AGIC pod should be in the default namespace (see column NAMESPACE). A healthy pod would have Running in the STATUS column. There should be at least one AGIC pod.
```
# Get a list of the Application Gateway Ingress Controller pods
kubectl get pods --all-namespaces --selector app=ingress-azure
```
If the AGIC pod isn't healthy (STATUS column from the previous command isn't Running), then:
- get logs to understand why: kubectl logs <pod-name>
- get logs for the previous instance of the pod: kubectl logs <pod-name> --previous
- describe the pod to get more context: kubectl describe pod <pod-name>

Do you have a Kubernetes Service and Ingress resources?

# Get all services across all namespaces
kubectl get service --all-namespaces -o wide

# Get all ingress resources across all namespaces
kubectl get ingress --all-namespaces -o wide

Is your Ingress annotated with: kubernetes.io/ingress.class: azure/application-gateway? AGIC only watches for Kubernetes Ingress resources that have this annotation.
```
# Get the YAML definition of a particular ingress resource
kubectl get ingress --namespace  <which-namespace?>  <which-ingress?>  -o yaml
```
AGIC emits Kubernetes events for certain critical errors. You can view these events:
- in your terminal via kubectl get events --sort-by=.metadata.creationTimestamp
- in your browser using the Kubernetes Web UI (Dashboard)

Logging Levels

AGIC has three logging levels. Level 1 is the default one and it shows minimal number of log lines. Level 5, on the other hand, would display all logs, including sanitized contents of config applied to ARM.

The Kubernetes community has established nine levels of logging for the kubectl tool. In this repository, we're utilizing three of these levels, with similar semantics:

Verbosity	Description
1	Default log level; shows startup details, warnings and errors
3	Extended information about events and changes; lists of created objects
5	Logs marshaled objects; shows sanitized JSON config applied to ARM

The verbosity levels are adjustable via the verbosityLevel variable in the helm-config.yaml file. Increase verbosity level to 5 to get the JSON config dispatched to ARM:

add verbosityLevel: 5 on a line by itself in helm-config.yaml and reinstall
get logs with kubectl logs <pod-name>

Sample Helm config file

# This file contains the essential configs for the ingress controller helm chart

# Verbosity level of the App Gateway Ingress Controller
verbosityLevel: 3

################################################################################
# Specify which application gateway the ingress controller manages
#
appgw:
    subscriptionId: <subscriptionId>
    resourceGroup: <resourceGroupName>
    name: <applicationGatewayName>

    # Setting appgw.shared to "true" creates an AzureIngressProhibitedTarget CRD.
    # This prohibits AGIC from applying config for any host/path.
    # Use "kubectl get AzureIngressProhibitedTargets" to view and change this.
    shared: false

################################################################################
# Specify which kubernetes namespace the ingress controller watches
# Default value is "default"
# Leaving this variable out or setting it to blank or empty string would
# result in Ingress Controller observing all accessible namespaces.
#
# kubernetes:
#   watchNamespace: <namespace>

################################################################################
# Specify the authentication with Azure Resource Manager
#
# Two authentication methods are available:
# - Option 1: AAD-Pod-Identity (https://github.com/Azure/aad-pod-identity)
armAuth:
    type: aadPodIdentity
    identityResourceID: <identityResourceId>
    identityClientID:  <identityClientId>

## Alternatively you can use Service Principal credentials
# armAuth:
#    type: servicePrincipal
#    secretJSON: <<Generate this value with: "az ad sp create-for-rbac --subscription <subscription-uuid> --role Contributor --sdk-auth | base64 -w0" >>

################################################################################
# Specify if the cluster is Kubernetes RBAC enabled or not
rbac:
    enabled: false # true/false

# Specify aks cluster related information. THIS IS BEING DEPRECATED.
aksClusterConfiguration:
    apiServerAddress: <aks-api-server-address>

Review Application Gateway Activity Log

When troubleshooting Application Gateway Ingress Controller issues, it's good practice to check the Application Gateway's Activity Log in addition to Kubernetes resources. Every time AGIC applies a new configuration, a corresponding entry is recorded in the Activity Log in the Azure portal. Reviewing these entries helps to confirm whether configuration updates were successfully applied and can often reveal gateway-related issues that aren't visible from the Kubernetes side.

Last updated on 2025-12-05