Adding Health Probes to your service

.. note:: Application Gateway for Containers has been released, which introduces numerous performance, resilience, and feature changes. Please consider leveraging Application Gateway for Containers for your next deployment.

Details on custom health probes in Application Gateway for Containers [may be found here](https://learn.microsoft.com/azure/application-gateway/for-containers/custom-health-probe).

By default, Ingress controller will provision an HTTP GET probe for the exposed pods. The probe properties can be customized by adding a Readiness or Liveness Probe to your deployment/pod spec.

With readinessProbe or livenessProbe

yaml apiVersion: apps/v1 kind: Deployment metadata: name: aspnetapp spec: replicas: 3 template: metadata: labels: service: site spec: containers: - name: aspnetapp image: mcr.microsoft.com/dotnet/samples:aspnetapp imagePullPolicy: IfNotPresent ports: - containerPort: 80 readinessProbe: httpGet: path: / port: 80 periodSeconds: 3 timeoutSeconds: 1

Kubernetes API Reference:

Note:

  1. readinessProbe and livenessProbe are supported when configured with httpGet.
  2. Probing on a port other than the one exposed on the pod is currently not supported.
  3. HttpHeaders, InitialDelaySeconds, SuccessThreshold are not supported.

Without readinessProbe or livenessProbe

If the above probes are not provided, then Ingress Controller make an assumption that the service is reachable on Path specified for backend-path-prefix annotation or the path specified in the ingress definition for the service.

Default Values for Health Probe

For any property that can not be inferred by the readiness/liveness probe, Default values are set.

Application Gateway Probe Property Default Value
Path /
Host localhost
Protocol HTTP
Timeout 30
Interval 30
UnhealthyThreshold 3