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Create a TypeScript function from the command line - Azure Functions
Learn how to create a TypeScript function from the command line, then publish the local project to serverless hosting in Azure Functions.
12/15/2023
quickstart
typescript
devx-track-azurecli, devx-track-azurepowershell, mode-other, devx-track-js, devx-track-ts
functions-nodejs-model

Quickstart: Create a TypeScript function in Azure from the command line

In this article, you use command-line tools to create a TypeScript function that responds to HTTP requests. After testing the code locally, you deploy it to the serverless environment of Azure Functions.

[!INCLUDE functions-nodejs-model-pivot-description]

Completion of this quickstart incurs a small cost of a few USD cents or less in your Azure account.

There's also a Visual Studio Code-based version of this article.

Configure your local environment

Before you begin, you must have the following prerequisites:

::: zone pivot="nodejs-model-v3"

  • Node.js version 14 or above. ::: zone-end ::: zone pivot="nodejs-model-v4"

  • Node.js version 18 or above.

  • TypeScript version 4+. ::: zone-end

[!INCLUDE functions-install-core-tools]

::: zone pivot="nodejs-model-v4"

  • Make sure you install version v4.0.5382 of the Core Tools, or a later version.
    ::: zone-end

Create a local function project

In Azure Functions, a function project is a container for one or more individual functions that each responds to a specific trigger. All functions in a project share the same local and hosting configurations. In this section, you create a function project that contains a single function.

::: zone pivot="nodejs-model-v3"

  1. In a suitable folder, run the func init command, as follows, to create a TypeScript Node.js v3 project in the current folder:

    func init --typescript --model V3

    This folder now contains various files for the project, including configurations files named local.settings.json and host.json. Because local.settings.json can contain secrets downloaded from Azure, the file is excluded from source control by default in the .gitignore file.

  2. Add a function to your project by using the following command, where the --name argument is the unique name of your function (HttpExample) and the --template argument specifies the function's trigger (HTTP).

    func new --name HttpExample --template "HTTP trigger" --authlevel "anonymous"

    func new creates a subfolder matching the function name that contains a code file appropriate to the project's chosen language and a configuration file named function.json.

(Optional) Examine the file contents

If desired, you can skip to Run the function locally and examine the file contents later.

index.ts

index.ts exports a function that's triggered according to the configuration in function.json.

:::code language="typescript" source="~/functions-quickstart-templates/Functions.Templates/Templates/HttpTrigger-TypeScript/index.ts":::

For an HTTP trigger, the function receives request data in the variable req of type HttpRequest as defined in function.json. The return object, defined as $return in function.json, is the response.

function.json

function.json is a configuration file that defines the input and output bindings for the function, including the trigger type.

:::code language="json" source="~/functions-quickstart-templates/Functions.Templates/Templates/HttpTrigger-JavaScript/function.json":::

Each binding requires a direction, a type, and a unique name. The HTTP trigger has an input binding of type httpTrigger and output binding of type http.

::: zone-end

::: zone pivot="nodejs-model-v4"

  1. In a suitable folder, run the func init command, as follows, to create a TypeScript Node.js v4 project in the current folder:

    func init --typescript

    This folder now contains various files for the project, including configurations files named local.settings.json and host.json. Because local.settings.json can contain secrets downloaded from Azure, the file is excluded from source control by default in the .gitignore file. Required npm packages are also installed in node_modules.

  2. Add a function to your project by using the following command, where the --name argument is the unique name of your function (HttpExample) and the --template argument specifies the function's trigger (HTTP).

    func new --name HttpExample --template "HTTP trigger" --authlevel "anonymous"

    func new creates a file named HttpExample.ts in the src/functions directory, which contains your function's code.

  3. Add Azure Storage connection information in local.settings.json.

    {
    "Values": {       
        "AzureWebJobsStorage": "<Azure Storage connection information>",
        "FUNCTIONS_WORKER_RUNTIME": "node"
    }
}

  4. (Optional) If you want to learn more about a particular function, say HTTP trigger, you can run the following command:

    func help httptrigger

::: zone-end

Run the function locally

  1. Run your function by starting the local Azure Functions runtime host from the LocalFunctionProj folder:

    ::: zone pivot="nodejs-model-v3"

    npm install
npm start

    ::: zone-end

    ::: zone pivot="nodejs-model-v4"

    npm start

    ::: zone-end

    Toward the end of the output, the following logs should appear:

    Screenshot of terminal window output when running function locally.

    [!NOTE] If HttpExample doesn't appear as shown in the logs, you likely started the host from outside the root folder of the project. In that case, use Ctrl+c to stop the host, navigate to the project's root folder, and run the previous command again.

  2. Copy the URL of your HttpExample function from this output to a browser and append the query string ?name=<your-name>, making the full URL like http://localhost:7071/api/HttpExample?name=Functions. The browser should display a message like Hello Functions:

    Result of the function run locally in the browser

    The terminal in which you started your project also shows log output as you make requests.

  3. When you're ready, use Ctrl+c and choose y to stop the functions host.

[!INCLUDE functions-create-azure-resources-cli]

  1. Create the function app in Azure:

    Azure CLI

    az functionapp create --resource-group AzureFunctionsQuickstart-rg --consumption-plan-location <REGION> --runtime node --runtime-version 18 --functions-version 4 --name <APP_NAME> --storage-account <STORAGE_NAME>

    The az functionapp create command creates the function app in Azure. It's recommended that you use the latest version of Node.js, which is currently 18. You can specify the version by setting --runtime-version to 18.

    Azure PowerShell

    New-AzFunctionApp -Name <APP_NAME> -ResourceGroupName AzureFunctionsQuickstart-rg -StorageAccount <STORAGE_NAME> -Runtime node -RuntimeVersion 18 -FunctionsVersion 4 -Location '<REGION>'

    The New-AzFunctionApp cmdlet creates the function app in Azure. It's recommended that you use the latest version of Node.js, which is currently 18. You can specify the version by setting --runtime-version to 18.

    In the previous example, replace <STORAGE_NAME> with the name of the account you used in the previous step, and replace <APP_NAME> with a globally unique name appropriate to you. The <APP_NAME> is also the default DNS domain for the function app.

    This command creates a function app running in your specified language runtime under the Azure Functions Consumption Plan, which is free for the amount of usage you incur here. The command also creates an associated Azure Application Insights instance in the same resource group, with which you can monitor your function app and view logs. For more information, see Monitor Azure Functions. The instance incurs no costs until you activate it.

Deploy the function project to Azure

Before you use Core Tools to deploy your project to Azure, you create a production-ready build of JavaScript files from the TypeScript source files.

  1. Use the following command to prepare your TypeScript project for deployment:

    npm run build

  2. With the necessary resources in place, you're now ready to deploy your local functions project to the function app in Azure by using the publish command. In the following example, replace <APP_NAME> with the name of your app.

    func azure functionapp publish <APP_NAME>

    If you see the error, "Can't find app with name ...", wait a few seconds and try again, as Azure may not have fully initialized the app after the previous az functionapp create command.

    The publish command shows results similar to the following output (truncated for simplicity):

     ...

 Getting site publishing info...
 Creating archive for current directory...
 Performing remote build for functions project.

 ...

 Deployment successful.
 Remote build succeeded!
 Syncing triggers...
 Functions in msdocs-azurefunctions-qs:
     HttpExample - [httpTrigger]
         Invoke url: https://msdocs-azurefunctions-qs.azurewebsites.net/api/httpexample?code=KYHrydo4GFe9y0000000qRgRJ8NdLFKpkakGJQfC3izYVidzzDN4gQ==

[!INCLUDE functions-run-remote-azure-cli]

[!INCLUDE functions-streaming-logs-cli-qs]

[!INCLUDE functions-cleanup-resources-cli]

Next steps

[!div class="nextstepaction"] Connect to an Azure Storage queue