Azure Functions 101 Playground 🚀

A simple, educational Azure Functions playground project for learning and experimenting with Azure Functions using the .NET isolated worker model.

📋 Overview

This project demonstrates the basics of Azure Functions v4 with the .NET isolated worker model. It's designed as a learning resource for developers getting started with serverless computing on Azure.

Features

• ✅ HTTP-triggered Azure Function
• ✅ Blob-triggered Function with output binding (copy blob between containers)
• ✅ .NET Framework 4.8 with isolated worker model
• ✅ Application Insights integration
• ✅ Ready for local development and Azure deployment

🛠️ Prerequisites

Before you begin, ensure you have the following installed:

• .NET Framework 4.8 SDK
• Azure Functions Core Tools v4
• Visual Studio 2022 or VS Code with C# extension
• Azure CLI (for deployment)
• Azurite or Azure Storage Emulator (for local development)

🚀 Getting Started

1. Clone the Repository

git clone https://github.com/yourusername/FunctionApp101.git
cd FunctionApp101

2. Configure Local Settings

Create a local.settings.json file in the FunctionApp101 folder:

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "FUNCTIONS_WORKER_RUNTIME": "dotnet-isolated",
    "APPLICATIONINSIGHTS_CONNECTION_STRING": "<your-connection-string>"
  }
}

Note: For local development, UseDevelopmentStorage=true requires Azurite to be running.

3. Run Locally

Using Azure Functions Core Tools:

cd FunctionApp101
func start

Or using Visual Studio:

• Open FunctionApp101.slnx
• Press F5 to start debugging

4. Test the Function

Once running, test the HTTP endpoint:

curl http://localhost:7071/api/Function1

Or open in your browser: http://localhost:7071/api/Function1

Expected response:

Welcome to Azure Functions!

Test the Blob Copy Function

1. Ensure Azurite is running for local storage emulation
2. Create a container named source-container in your storage
3. Upload a blob to source-container
4. The function will automatically copy it to destination-container

You can use Azure Storage Explorer or Azure CLI:

# Create containers (if using Azure Storage)
az storage container create --name source-container --connection-string "<your-connection-string>"
az storage container create --name destination-container --connection-string "<your-connection-string>"

# Upload a test file
az storage blob upload --container-name source-container --file test.txt --name test.txt --connection-string "<your-connection-string>"

📁 Project Structure

FunctionApp101/
├── FunctionApp101.slnx          # Solution file
├── .gitignore                   # Git ignore rules
├── README.md                    # This file
├── LICENSE                      # MIT License
└── FunctionApp101/              # Function App project
    ├── Function1.cs             # HTTP trigger function
    ├── BlobCopyFunction.cs      # Blob trigger with output binding
    ├── Program.cs               # Application entry point
    ├── FunctionApp101.csproj    # Project file
    ├── host.json                # Host configuration
    └── local.settings.json      # Local settings (not in git)

📚 Learning Resources

About Azure Functions

Azure Functions is a serverless compute service that enables you to run event-triggered code without having to explicitly provision or manage infrastructure.

Key Concepts Demonstrated

1. HTTP Triggers: Functions that respond to HTTP requests
2. Blob Triggers: Functions that respond to blob storage events
3. Output Bindings: Declarative way to write data to external services
4. Isolated Worker Model: Out-of-process execution model for better flexibility
5. Dependency Injection: Using ILoggerFactory for logging
6. Application Insights: Telemetry and monitoring integration

Useful Links

• Azure Functions Documentation
• .NET Isolated Worker Guide
• Azure Functions Core Tools
• Application Insights for Azure Functions

🔧 Configuration

host.json

The host.json file contains global configuration options:

{
  "version": "2.0",
  "logging": {
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": true,
        "excludedTypes": "Request"
      },
      "enableLiveMetricsFilters": true
    }
  }
}

Environment Variables

Variable	Description
AzureWebJobsStorage	Connection string for Azure Storage
FUNCTIONS_WORKER_RUNTIME	Set to dotnet-isolated
APPLICATIONINSIGHTS_CONNECTION_STRING	Application Insights connection string

🚢 Deployment

Deploy to Azure using Azure CLI

1. Create a resource group:

az group create --name rg-functionapp101 --location eastus

2. Create a storage account:

az storage account create --name stfunctionapp101 --location eastus --resource-group rg-functionapp101 --sku Standard_LRS

3. Create a function app:

az functionapp create --resource-group rg-functionapp101 --consumption-plan-location eastus --runtime dotnet-isolated --functions-version 4 --name functionapp101 --storage-account stfunctionapp101

4. Deploy the function:

func azure functionapp publish functionapp101

Deploy using Visual Studio

1. Right-click on the project in Solution Explorer
2. Select Publish
3. Choose Azure → Azure Function App (Windows)
4. Follow the wizard to create or select a Function App

🧪 Extending the Project

Adding a New Function

1. Create a new .cs file in the project
2. Add the function class with [Function] attribute:

public class MyNewFunction
{
    private readonly ILogger _logger;

    public MyNewFunction(ILoggerFactory loggerFactory)
    {
        _logger = loggerFactory.CreateLogger<MyNewFunction>();
    }

    [Function("MyNewFunction")]
    public HttpResponseData Run(
        [HttpTrigger(AuthorizationLevel.Anonymous, "get")] HttpRequestData req)
    {
        _logger.LogInformation("Processing request...");
        
        var response = req.CreateResponse(HttpStatusCode.OK);
        response.WriteString("Hello from MyNewFunction!");
        return response;
    }
}

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• Azure Functions Team
• Microsoft Learn

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Happy Coding! 🎉

If you find this project helpful, please give it a ⭐ on GitHub!