Welcome to a preview of .NET 5 in Azure Functions. .NET 5 functions run in an out-of-process language worker that is separate from the Azure Functions runtime. This allows you to have full control over your application's dependencies as well as other new features like a middleware pipeline.
A .NET 5 function app works differently than a .NET Core 3.1 function app. For .NET 5, you build an executable that imports the .NET 5 language worker as a NuGet package. Your app includes a Program.cs
that starts the worker.
If you've built .NET Core 3.1 Azure Functions before, the rest of a .NET 5 Azure Functions app should look quite familiar. Refer to the information in this README for how to get started and for more details about the main differences.
As this is a preview, there may be some breaking changes to be expected.
Download .NET 5.0 from here
Please make sure you have Azure Functions Core Tools >= 3.0.3160
.
To download, please check out our docs at Azure Functions Core Tools
Here are the important artifacts in a .NET 5 Azure Functions app (FunctionApp
folder).
{
"IsEncrypted": false,
"Values": {
"FUNCTIONS_WORKER_RUNTIME": "dotnet-isolated",
"AzureWebJobsStorage": ""
}
}
FUNCTIONS_WORKER_RUNTIME
- Set this to a value ofdotnet-isolated
. This is likely to change in the future as this worker is intended for future .NET versions as well.AzureWebJobsStorage
- Some of the functions in the sample require a Storage account. Set the value ofAzureWebJobsStorage
to the connection string to a valid Storage account or running Storage Emulator.
There are some main differences between a .NET 5 Azure Functions project compared to .NET Core 3.1.
TargetFramework
andOutputType
- A .NET 5 Azure Functions app is a .NET 5 executable (console app) that runs in a process that is separate from the Azure Functions host.AzureFunctionsVersion
- .NET 5 Azure Functions still uses thev3
Azure Functions host._FunctionsSkipCleanOutput
- Ensure this is set to prevent the build process from removing important files in the output.
<PropertyGroup>
<TargetFramework>net5.0</TargetFramework>
<LangVersion>preview</LangVersion>
<AzureFunctionsVersion>v3</AzureFunctionsVersion>
<OutputType>Exe</OutputType>
<_FunctionsSkipCleanOutput>true</_FunctionsSkipCleanOutput>
</PropertyGroup>
Also note the package references needed for the .NET 5 worker. You can use other .NET 5 compatible packages in your project.
For functions attributes to work, you also need to reference the appropriate WebJobs SDK packages that contain the required types.
Like .NET Core 3.1 function apps, functions are in C# files. They are currently separated into folders but, like .NET Core 3.1 functions, they can be organized differently if you wish.
One important difference with .NET 5 functions is that "rich bindings", such as Durable Functions or binding to SDK types like Cosmos DB client, are not supported. Use strings and C# objects (POCOs). For HTTP, use HttpRequestData
and HttpResponseData
objects.
Function1
- An HTTP trigger with a Blob input and a Queue output.Function2
- A Queue trigger with a Blob input.Function3
- An HTTP trigger with a Queue output.Function4
- A simple HTTP trigger.Function5
- An HTTP triggered function that demonstrates dependency injection.
The Azure Functions .NET Worker supports middleware registration, following a model similar to what exists in ASP.NET and giving you the ability to inject logic into the invocation pipeline, pre and post function executions.
While the full middleware registration set of APIs is not yet exposed, middleware registration is supported and we've added an example to the sample application under the Middleware
folder.
In the FunctionApp
folder, run func host start
[Optional --verbose
]. This will preform a build and then run the host.
cd FunctionApp
func host start --verbose
Ensure version 1.1.0 or later of the Azure Functions VS Code extension is installed and you have this repo open at the root. In the "Run" icon in the Activity Bar, select the Attach to .NET Functions
launch task and click the "Start Debugging" button or press F5
. The app will start and the debugger will attach.
To debug in Visual Studio, uncomment the Debugger.Launch()
statements in Program.cs. The process will attempt to launch a debugger before continuing.
YOU CAN NOT DEBUG DIRECTLY USING "Start Debugging" IN VISUAL STUDIO DIRECTLY. You need to use the command line as mentioned in the previous Run the sample locally part of this readme.
We're working with the Visual Studio team to provide an integrated debugging experience.
-
To deploy the app, first ensure that you've installed the Azure CLI.
-
Login to the CLI.
az login
-
If necessary, use
az account set
to select the subscription you want to use. -
Create a resource group, Storage account, and Azure Functions app.
az group create --name AzureFunctionsQuickstart-rg --location westeurope az storage account create --name <STORAGE_NAME> --location westeurope --resource-group AzureFunctionsQuickstart-rg --sku Standard_LRS az functionapp create --resource-group AzureFunctionsQuickstart-rg --consumption-plan-location westeurope --runtime dotnet --functions-version 3 --name <APP_NAME> --storage-account <STORAGE_NAME>
-
Ensure you're in your functions project (
FunctionApp
) folder. -
Publish the .NET project.
dotnet publish -c Release
-
Cd into the publish artifacts.
cd ./bin/Release/net5.0/publish
-
Deploy the app.
func azure functionapp publish <APP_NAME>
- Deployment to Azure is currently limited to Windows plans. Note that some optimizations are not in place in the consumption plan and you may experience longer cold starts.
Please create issues in this repo. Thanks!
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