Azure Claim Check Pattern Implementation

Description

This project implements the Claim Check pattern to handle large payloads. Instead of sending heavy data via message bus, it stores the content in Azure Blob Storage and sends a reference (URI) to the consumer. This optimizes performance, reduces messaging costs, and bypasses provider size limits.

---

🛠 Infrastructure Components

The infrastructure is managed via Terraform and includes:

• Azure Storage Account: Persistent store for large message payloads.
• Azure Service Bus: Messaging queue for small pointers (claims).
• Azure Event Grid: System for reactive event-driven triggers.
• Azure Functions: Serverless processing logic (Python).
• Azure Monitor: Monitor infraestructure and custom metrics.

---

🏗 Technical Architecture

1. Producer: Uploads large data to Blob Storage and sends a small JSON message to Service Bus containing the Blob URI (the message is sent via Event Grid). Files are uploaded using the Azure Storage Uploader
2. Messaging: Service Bus triggers the Azure Function upon receiving the claim.
3. Consumer (Function): Reads the URI, downloads the full payload from Storage, and executes the business logic. Send some metrics to Azure Monitor Custom Metrics API.

---

🚀 Getting Started

1. Prerequisites

• Azure CLI
• Terraform
• Azure Functions Core Tools
• Python 3.9+

2. Clone the Repository

git clone https://github.com/jonmunm/azure-claim_check.git
cd azure_claim_check

3. Deploy Infrastructure (Terraform)

Provision the Azure resources. There are two important parameters:

• deployment_id: An ID to identify the deployed infrastructure
• personal_principal_id: Principal ID of your Azure user. Permissions granted to this user:
  • STORAGE BLOB DATA CONTRIBUTOR: to upload files to the Storage Account and fire the orchestration
  • MONITORING METRICS PUBLISHER: to optionally log the uploading process to Log Analytics

cd infra
terraform init
terraform plan
terraform apply --auto-approve --var="deployment_id=<ID>" --var="personal_principal_id=<ID>"

4. Local Development (Azure Functions)

• Create your src/local.settings.json file.
• Set up the Python environment (if needed):

cd ../src
python -m venv .venv
source .venv/bin/activate  # Windows: .venv\Scripts\activate
pip install -r requirements.txt

• Run the function:

func start

📖 Reference Documentation

1. Microsoft: Claim-Check Pattern
2. Enterprise Integration Patterns: Claim Check