gh-lucaspimentel-claude-code-plugins-plugins-dd-trace-dotnet-azure-functions/commands/create-sample-function.md

description

description
Create a sample Azure Function for testing

Create a sample Azure Function application for testing Datadog instrumentation.

Choose Function Type

1. In-Process Function (.NET 6+)

Create project:

func init MyFunctionApp --worker-runtime dotnet
cd MyFunctionApp
func new --template "HTTP trigger" --name HttpTrigger

Add Datadog NuGet package:

<PackageReference Include="Datadog.AzureFunctions" Version="X.X.X" />

Update Program.cs (.NET 6+ in-process):

using Microsoft.Extensions.Hosting;

var host = new HostBuilder()
    .ConfigureFunctionsWorkerDefaults()
    .Build();

host.Run();

2. Isolated Worker Function (.NET 7+)

Create project:

func init MyFunctionApp --worker-runtime dotnet-isolated
cd MyFunctionApp
func new --template "HTTP trigger" --name HttpTrigger

Add Datadog NuGet package:

<PackageReference Include="Datadog.AzureFunctions" Version="X.X.X" />

Update Program.cs:

using Microsoft.Extensions.Hosting;

var host = new HostBuilder()
    .ConfigureFunctionsWorkerDefaults()
    .Build();

host.Run();

3. In-Process Function (.NET Framework 4.8)

Create project (requires Visual Studio or manual setup):

<TargetFramework>net48</TargetFramework>
<AzureFunctionsVersion>v4</AzureFunctionsVersion>

For .NET Framework, use the Site Extension deployment method instead of NuGet.

Configure Settings

local.settings.json

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "FUNCTIONS_WORKER_RUNTIME": "dotnet",
    "DD_API_KEY": "your-api-key-here",
    "DD_SITE": "datadoghq.com",
    "DD_ENV": "dev",
    "DD_SERVICE": "my-function-app",
    "DD_VERSION": "1.0.0",
    "DD_TRACE_DEBUG": "false"
  }
}

Add Instrumentation Code (Optional)

For custom spans:

using Datadog.Trace;

public class HttpTrigger
{
    [FunctionName("HttpTrigger")]
    public async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Function, "get", "post")] HttpRequest req,
        ILogger log)
    {
        using var scope = Tracer.Instance.StartActive("custom.operation");
        scope.Span.SetTag("custom.tag", "value");

        // Your function logic

        return new OkObjectResult("Hello from Datadog!");
    }
}

Test Locally

Run the function:

func start

Invoke the function:

curl http://localhost:7071/api/HttpTrigger

Verify traces:

• Check Datadog APM for traces
• Review local logs for tracer messages
• Confirm spans are created

Deploy to Azure

Using Azure CLI:

Create function app:

az functionapp create \
  --resource-group lucas.pimentel \
  --consumption-plan-location eastus \
  --runtime dotnet \
  --functions-version 4 \
  --name lucasp-test-function \
  --storage-account <storage-account>

Deploy:

func azure functionapp publish lucasp-test-function

Configure Datadog settings:

az functionapp config appsettings set \
  --name lucasp-test-function \
  --resource-group lucas.pimentel \
  --settings DD_API_KEY=<key> DD_SITE=datadoghq.com DD_ENV=test

Add Different Trigger Types

Timer Trigger:

func new --template "Timer trigger" --name TimerTrigger

Queue Trigger:

func new --template "Queue trigger" --name QueueTrigger

Blob Trigger:

func new --template "Blob trigger" --name BlobTrigger

Test Integration Points

HTTP calls:

using var httpClient = new HttpClient();
var response = await httpClient.GetAsync("https://api.example.com");

Database calls:

using var connection = new SqlConnection(connectionString);
await connection.OpenAsync();

Azure SDK calls:

var blobClient = new BlobClient(connectionString, containerName, blobName);
await blobClient.DownloadAsync();

Reference Sample Applications

For working examples, see:

tracer/test/test-applications/azure-functions/

These samples demonstrate:

• Different runtime versions
• In-process vs isolated worker
• Various trigger types
• Custom instrumentation
• Datadog configuration