502 Bad Gateway and unhealthy probe in AGIC AppGW

[arunkumarguggila]

My application is with Angular FE and multiple Asp.net core web api's. I have deployed this in AKS and configured Appgw AGIC. My Ingress controller details

Name: ingress-appgw-deployment-xxxxxxxx-xxxx Namespace: kube-system Priority: 0 Service Account: ingress-appgw-sa Node: aks-agentpool-xxxxxxx-vmss000000/10.224.1.255 Start Time: Fri, 01 Mar 2024 02:16:47 +0400 Labels: app=ingress-appgw kubernetes.azure.com/managedby=aks pod-template-hash=6d4f68fc9f Annotations: checksum/config: 1e53b6ba909ce787812767da80976912cc41007f8a716c489edab91f215b2bd7 cluster-autoscaler.kubernetes.io/safe-to-evict: true kubernetes.azure.com/metrics-scrape: true prometheus.io/path: /metrics prometheus.io/port: 8123 prometheus.io/scrape: true resource-id: /subscriptions/ea88e1ed-fec0-472f-87f5-a00e6a608f19/resourceGroups/AZ-BELSIO-SOFTWARES-RG/providers/Microsoft.ContainerService/managedClus... Status: Running IP: 10.224.x.xx IPs: IP: 10.224.x.xx Controlled By: ReplicaSet/ingress-appgw-deployment-6d4f68fc9f Containers: ingress-appgw-container: Container ID: containerd://de72b0a2d86ffd7e11113b0ee38a374b509b212d56eac166391d28d4ae81849c Image: mcr.microsoft.com/azure-application-gateway/kubernetes-ingress:1.7.2 Image ID: mcr.microsoft.com/azure-application-gateway/kubernetes-ingress@sha256:eeb1d42ebfb872478d9b0b16f6936ea938d6e5eed4a59cde332b8757556a5e1f Port: Host Port: State: Running Started: Fri, 01 Mar 2024 02:18:47 +0400 Last State: Terminated Reason: Error Exit Code: 255 Started: Fri, 01 Mar 2024 02:17:55 +0400 Finished: Fri, 01 Mar 2024 02:17:56 +0400 Ready: True Restart Count: 4 Limits: cpu: 700m memory: 600Mi Requests: cpu: 100m memory: 20Mi Liveness: http-get http://:8123/health/alive delay=15s timeout=1s period=20s #success=1 #failure=3 Readiness: http-get http://:8123/health/ready delay=5s timeout=1s period=10s #success=1 #failure=3 Environment Variables from: ingress-appgw-cm ConfigMap Optional: false Environment: AGIC_POD_NAMESPACE: kube-system (v1:metadata.namespace) KUBERNETES_PORT_443_TCP_ADDR: belsio-dns-yvu9cnmb.hcp.uaenorth.azmk8s.io KUBERNETES_PORT: tcp://myapp-dns-yvu9cnmb.hcp.uaenorth.azmk8s.io:443 KUBERNETES_PORT_443_TCP: tcp://myapp-dns-yvu9cnmb.hcp.uaenorth.azmk8s.io:443 KUBERNETES_SERVICE_HOST: myapp-dns-yvu9cnmb.hcp.uaenorth.azmk8s.io AZURE_CLOUD_PROVIDER_LOCATION: /etc/kubernetes/azure.json AGIC_POD_NAME: ingress-appgw-deployment-6d4f68fc9f-xtlmk (v1:metadata.name) Mounts: /etc/kubernetes/azure.json from cloud-provider-config (ro) /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-9kcms (ro) Conditions: Type Status Initialized True Ready True ContainersReady True PodScheduled True Volumes: cloud-provider-config: Type: HostPath (bare host directory volume) Path: /etc/kubernetes/azure.json HostPathType: File kube-api-access-9kcms: Type: Projected (a volume that contains injected data from multiple sources) TokenExpirationSeconds: 3607 ConfigMapName: kube-root-ca.crt ConfigMapOptional: DownwardAPI: true QoS Class: Burstable Node-Selectors: Tolerations: CriticalAddonsOnly op=Exists node.kubernetes.io/memory-pressure:NoSchedule op=Exists node.kubernetes.io/not-ready:NoExecute op=Exists for 300s node.kubernetes.io/unreachable:NoExecute op=Exists for 300s Events: My ingress congiguration

apiVersion: networking.k8s.io/v1 kind: Ingress metadata: name: myapp namespace: default annotations: kubernetes.io/ingress.class: azure/application-gateway spec: tls:

• hosts:
  • app.example.com rules:
• host: app.example.com http: paths:
  • path: / pathType: Exact backend: service: name: angular port: number: 80
  • path: /api1 pathType: Prefix backend: service: name: api1 port: number: 80
  • path: /api2 pathType: Prefix backend: service: name: api2 port: number: 80 Expected: domain root path will route to Angular App and /api1 and /api2 to api's. I was able to achieve this in minikube using nginx IC using the same ingress configuration.

Issue: Angular is accessible but cannot access API's. I checked APIs by assigning a public and it's accessible but cannot with the ingress. In the health check, Angular pods are healthy but api pods are unhealth with the below message.

"Received invalid status code: 404 in the backend server’s HTTP response. As per the health probe configuration, 200-399 is the acceptable status code. Either modify probe configuration or resolve backend issues. To learn more visit - https://aka.ms/StatusCodeMismatch."

Please help me fix this and also suggest additional configurations that you think might help me.

Thank you in advance.

[ntsh999]

were you able to find any fix for this issue? I am also facing this issue?

[arunkumarguggila]

Yes, for me the issue was with the root prefix in the swagger config. once that's set everything worked perfectly.