Function Runner Design

Mon, 01 Jan 0001 00:00:00 +0000

Architectural Context

The Function Runner is one of several function execution mechanisms in Porch. The Task Handler uses a Function Runtime interface that can be implemented by:

Task Handler (in Porch)
 ↓
 Function Runtime
 ↓
 ┌─────┴─────┬──────────┐
 ↓ ↓ ↓
Builtin gRPC Multi
Runtime Runtime Runtime
 ↓ ↓ ↓
In-Process Function Chains
Go Code Runner Runtimes
 (External)
 ↓
 ┌─────────┴─────────┬──────────┐
 ↓ ↓ ↓
 Pod Executable Multi
 Evaluator Evaluator Evaluator
 ↓ ↓ ↓
 Function Cached Fallback
 Pods Binaries Chain

Function Runtime implementations:

Function Runner Interactions

Mon, 01 Jan 0001 00:00:00 +0000

Overview

The Function Runner is a separate gRPC service that interacts with multiple systems: the Task Handler (via gRPC), Kubernetes API (for pod management, FunctionConfig objects, and pod/service templates), container registries (for image metadata), and wrapper servers (for function execution). It operates independently from the Porch server, enabling isolated function execution.

An embedded FunctionConfig reconciler watches FunctionConfig objects in the function-pod namespace and fills an in-memory store. That store is how the executable evaluator resolves binaries and how the pod evaluator applies per-image TTL, parallelism, and template overrides. Go execution is not handled here; it runs in porch-server / porch-controllers. See Function Configuration.

Function Runner on Porch Documentation

Function Runner Design

Architectural Context

Function Runner Interactions

Overview