Multi-Cloud Function Providers Guide

This guide is the multi-cloud entry point for TPF function deployments. It shows how the same FUNCTION platform mode can target AWS Lambda, Azure Functions, and Google Cloud Run functions while keeping the typed business flow unchanged.

Overview

TPF supports three major cloud function platforms:

Provider	Extension	Handler Interface	Local Testing
AWS Lambda	quarkus-amazon-lambda	RequestHandler<I, O>	Mock event server
Azure Functions	quarkus-azure-functions	HTTP trigger + REST	Core Tools v4.x
Google Cloud Run functions	quarkus-google-cloud-functions	HttpFunction	Functions Framework

Important runtime constraint:

• FUNCTION currently requires REST transport. gRPC is not a supported FUNCTION transport in the current implementation.
• Google's current product name is Cloud Run functions, while the current Quarkus extension name remains quarkus-google-cloud-functions.

Architecture

Step-Level Handlers

Step-level pipeline handlers (e.g., CrawlSourceFunctionHandler, ParseDocumentFunctionHandler) are fully multi-cloud ready. The framework generates provider-specific handlers based on:

1. Explicit configuration: -Dpipeline.function.provider=aws|azure|gcp
2. Auto-detection: Based on Quarkus extension in classpath
3. Default: AWS Lambda

Orchestrator Handlers

The orchestrator handler (PipelineRunFunctionHandler) generates provider-specific handlers for each cloud platform:

• AWS Lambda: Implements RequestHandler<I, O> with Lambda Context
• Azure Functions: POJO with ExecutionContext parameter
• Google Cloud Run functions: Implements HttpFunction with HttpRequest/HttpResponse

All providers preserve FUNCTION platform semantics (cardinality, failure handling) and support async handlers (run-async, status, result). Azure and GCP FUNCTION deployments use the required REST transport approach, where HTTP triggers route requests to Quarkus REST endpoints while preserving FUNCTION semantics.

What this guide covers and does not cover

This guide covers the current repo-supported FUNCTION targets:

1. AWS Lambda
2. Azure Functions
3. Google Cloud Run functions

It does not currently document or implement:

1. Google Cloud Run services as a generic container/service target,
2. Azure Durable Functions as a separate TPF runtime model,
3. gRPC as a FUNCTION transport.

If you need queue-backed recovery, checkpoint handoff, or orchestrator-managed HA, use the COMPUTE + QUEUE_ASYNC path instead of treating function providers as a replacement for that runtime model.

Quick Start

AWS Lambda

# Build
./build-lambda.sh -DskipTests

# Test
./mvnw -pl orchestrator-svc \
  -Dtpf.build.platform=FUNCTION \
  -Dtpf.build.transport=REST \
  -Dtpf.build.rest.naming.strategy=RESOURCEFUL \
  -Dtpf.build.lambda.scope=compile \
  -Dquarkus.profile=lambda \
  -Dtest=LambdaMockEventServerSmokeTest \
  test

See AWS Lambda Platform Guide for detailed deployment instructions.

Azure Functions

# Build
./build-azure.sh -DskipTests

# Test
./mvnw -pl orchestrator-svc \
  -Dtpf.build.platform=FUNCTION \
  -Dtpf.build.transport=REST \
  -Dtpf.build.rest.naming.strategy=RESOURCEFUL \
  -Dtpf.build.azure.scope=compile \
  -Dquarkus.profile=azure-functions \
  -Dtest=AzureFunctionsBootstrapSmokeTest \
  test

See Azure Functions Testing Guide for detailed deployment instructions.

Google Cloud Run functions

# Build
./build-gcp.sh -DskipTests

# Test
./mvnw -pl orchestrator-svc \
  -Dtpf.build.platform=FUNCTION \
  -Dtpf.build.transport=REST \
  -Dtpf.build.rest.naming.strategy=RESOURCEFUL \
  -Dtpf.build.gcp.scope=compile \
  -Dquarkus.profile=gcp-functions \
  -Dtest=GcpFunctionsBootstrapSmokeTest \
  test

Configuration

Build Properties

Property	Description	Values	Default
tpf.build.platform	Target platform	COMPUTE, FUNCTION	COMPUTE
tpf.build.transport	Transport protocol for FUNCTION builds	REST	REST
tpf.build.lambda.scope	Lambda dependency scope	compile, provided	provided
tpf.build.azure.scope	Azure dependency scope	compile, provided	provided
tpf.build.gcp.scope	GCP dependency scope	compile, provided	provided
quarkus.profile	Quarkus profile	lambda, azure-functions, gcp-functions	-

FUNCTION is a platform mode, not a transport. Function-provider builds generate provider handler artifacts and currently require REST transport; gRPC remains a transport option for COMPUTE deployments.

Provider Selection

The framework selects the provider using this precedence:

1. Explicit: -Dpipeline.function.provider=aws|azure|gcp
2. Auto-detect: Based on Quarkus extension in classpath
3. Default: AWS Lambda

Provider Comparison

AWS Lambda

Strengths:

• Mature ecosystem with extensive integrations
• SnapStart for cold start mitigation
• Native support for streaming payloads
• Comprehensive monitoring via CloudWatch

Considerations:

• Maximum execution time: 15 minutes
• Memory: 128MB - 10GB
• Deployment package size limits

Azure Functions

Strengths:

• Premium plan with pre-warmed instances
• Strong integration with Azure ecosystem
• Flexible pricing (Consumption, Premium, Dedicated)
• Application Insights for monitoring

Considerations:

• Maximum execution time varies by plan
• Cold starts on Consumption plan
• Storage account dependency

Google Cloud Run functions

Strengths:

• Simple deployment model
• Tight integration with GCP services
• Cloud Monitoring and Logging
• 2nd gen functions with improved performance

Considerations:

• Maximum execution time: 9 minutes (1st gen), 60 minutes (2nd gen)
• Memory: 128MB - 32GB
• Cold starts on standard tier

Wire Protocol

TPF uses protobuf-over-HTTP as the default wire protocol for remote function invocations:

• Payloads wrapped in BytesValue protobuf messages
• Content-Type: application/x-protobuf
• JSON fallback when protobuf not configured

This is cloud-agnostic and works identically across all providers.

Testing Strategy

Local Testing

Provider	Test Class	Requirements
AWS Lambda	LambdaMockEventServerSmokeTest	None
Azure Functions	AzureFunctionsBootstrapSmokeTest	None
Google Cloud Run functions	GcpFunctionsBootstrapSmokeTest	None

Integration Testing

Provider	Test Class	Requirements
AWS Lambda	*-EndToEndIT	AWS credentials, SAM/CloudFormation
Azure Functions	AzureFunctionsEndToEndIT	Azure subscription, Terraform
Google Cloud Run functions	GcpFunctionsBootstrapSmokeTest	Build with the gcp-functions profile; validates Quarkus Functions extension bootstrap and HttpFunction loading only

Troubleshooting

Common Issues

Multiple providers detected:

[TPF] Multiple function providers detected. Using AWS Lambda (aws).

Solution: Set explicit provider: -Dpipeline.function.provider=azure

Extension not on classpath:

ClassNotFoundException: com.google.cloud.functions.HttpFunction

Solution: Build with correct scope: -Dtpf.build.gcp.scope=compile

Next Steps

• Review provider-specific guides for detailed deployment instructions
• See Function Platform Architecture for implementation details
• Consult Operations Playbook for production guidance