[feature request] Support gRPC-based liveness/readiness probes in PodProbe

[arnavgogia20]

Feature Request: gRPC Probe Support

Background

Kubernetes natively supports gRPC-based liveness and readiness probes using the standard grpc.health.v1.Health protocol. These probes are increasingly common in modern, gRPC-native microservice architectures.

However, the OpenKruise PodProbe daemon currently does not support gRPC probes. An unresolved TODO exists in the probe implementation, resulting in gRPC probe configurations being ignored.

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Current Limitation

File:

• pkg/daemon/podprobe/prober.go (around line 83)

The probe logic lacks handling for gRPC probe definitions, creating a feature gap compared to kubelet behavior and limiting compatibility with workloads that rely on gRPC health checks.

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Proposal

Add support for gRPC probes in the PodProbe daemon by:

• Detecting gRPC probe configurations in container specs
• Implementing health checks using the standard grpc.health.v1.Health protocol
• Respecting probe configuration fields such as:
  • timeoutSeconds
  • failureThreshold
  • successThreshold
• Ensuring behavior is consistent with Kubernetes kubelet semantics

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Impact

• Improves compatibility with gRPC-native applications
• Aligns OpenKruise PodProbe behavior with upstream Kubernetes
• Enables broader adoption for service-mesh and modern microservice workloads

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[arnavgogia20]

/assign