3.1 KiB
Azure Functions
Serverless compute for event-driven workloads, APIs, and scheduled tasks.
⚠️ MANDATORY: Use Composition Algorithm
NEVER synthesize Bicep or Terraform from scratch for Azure Functions.
You MUST follow the base + recipe composition workflow:
- Load selection.md — decision tree for choosing base template + recipe
- Follow composition.md — the algorithm for fetching and composing
This ensures proven IaC patterns, correct RBAC, and Flex Consumption defaults.
When to Use
- Event-driven workloads
- Scheduled tasks (cron jobs)
- HTTP APIs with variable traffic
- Message/queue processing
- Real-time file processing
- MCP servers for AI agents
- Real-time streaming and event processing
- Orchestrations and workflows (Durable Functions)
Service Type in azure.yaml
services:
my-function:
host: function
project: ./src/my-function
Required Supporting Resources
| Resource | Purpose |
|---|---|
| Storage Account | Function runtime state |
| App Service Plan | Hosting (Consumption or Premium) |
| Application Insights | Monitoring |
Hosting Plans
Use Flex Consumption for new deployments (all AZD templates default to Flex).
For the full comparison matrix (scale limits, instance sizing, deployment slots, cost model, and a decision tree), see hosting-plans.md. For mitigating cold starts on any plan, see cold-start.md.
Runtime Stacks
⚠️ ALWAYS QUERY OFFICIAL DOCUMENTATION FOR VERSIONS
Do NOT use hardcoded versions. Query for latest GA versions before generating code:
Primary Source: Azure Functions Supported Languages
Use the azure-documentation MCP tool to fetch current supported versions:
intent: "Azure Functions supported language runtime versions" learn: true
Version Selection Priority
- Latest GA — For new projects (best features, longest support window)
- LTS — For enterprise/compliance requirements
- User-specified — When explicitly requested
| Language | FUNCTIONS_WORKER_RUNTIME | linuxFxVersion |
|---|---|---|
| Node.js | node |
Node|<version> |
| Python | python |
Python|<version> |
| .NET | dotnet-isolated |
DOTNET-ISOLATED|<version> |
| Java | java |
Java|<version> |
| PowerShell | powershell |
PowerShell|<version> |
References
- Selection Guide — Start here: decision tree for base + recipe
- Composition Algorithm — How to fetch and compose templates
- AZD Templates — Template overview
- Bicep Patterns
- Terraform Patterns
- Durable Functions
- Aspire + Container Apps
- Hosting Plans Comparison — Consumption vs Flex vs Premium vs Dedicated vs Container Apps
- Cold Start Mitigation — Per-plan strategies and CLI/Bicep examples