Deno for Azure Functions

           @@@@@@@@@@@,         
       @@@@@@@@@@@@@@@@@@@                        %%%%%%
     @@@@@@        @@@@@@@@@@                    %%%%%%
   @@@@@ @  @           *@@@@@              @   %%%%%%    @
   @@@                    @@@@@           @@   %%%%%%      @@
  @@@@@                   @@@@@        @@@    %%%%%%%%%%%    @@@
  @@@@@@@@@@@@@@@          @@@@      @@      %%%%%%%%%%        @@
   @@@@@@@@@@@@@@          @@@@        @@         %%%%       @@
    @@@@@@@@@@@@@@         @@@           @@      %%%       @@
     @@@@@@@@@@@@@         @               @@    %%      @@
       @@@@@@@@@@@                              %%
            @@@@@@@                             %

Overview

This is a worker that lets you run Deno on Azure Functions. It is implemented as an Azure Functions Custom Handler and runs on the Azure Functions Consumption (serverless) plan.

The project includes a CLI denofunc to make it easy to create, run, and deploy your Deno Azure Functions apps.

3 commands to get started

# initialize function app
denofunc init

# run function app locally
denofunc start

# deploy the app
denofunc publish $functionAppName [--slot $slotName] [--allow-run] [--allow-write]

For more information, try the quickstart below.

Programming model

All Azure Functions triggers and bindings (including custom bindings) are supported.

In this simplified programming model, each function is a single file. Here are a couple of examples:

Check out the new project template for the entire app structure.

Getting started - building a Deno function app

Requirements

Linux, macOS, Windows
Deno
- Tested on:
  - 1.16.2
Azure Functions Core Tools V3 - needed for running the app locally and deploying it
Azure CLI - needed to deploy the app
denofunc CLI - see below

Codespaces
You can also get a preconfigured, cloud-based dev environment from Codespaces:

Visual Studio Codespaces - click to create

GitHub Codespaces (private preview) - go to the template repo and create a Codespace

Install the denofunc CLI

To help create, run, and deploy a Deno for Azure Functions app, you need to install the denofunc CLI. denofunc wraps the Azure Functions Core Tools (func) and is used for generating artifacts required to run/deploy the app.

To install the CLI, run the following Deno command.

deno install --allow-run --allow-read --allow-write --allow-net --unstable --force \
    --name=denofunc https://raw.githubusercontent.com/anthonychu/azure-functions-deno-worker/v0.8.0/denofunc.ts

Confirm it is installed correctly:

denofunc --help

Create and run an app locally

Create and change into an empty folder.
Initialize the project:
```
denofunc init
```
A few of the files that are important to know about:
- functions/hello_world.ts - a basic HTTP triggered function
- worker.ts - the Deno worker used by Azure Functions
- host.json - configuration of the function host
Run the app locally:
```
denofunc start
```
The Azure Functions Core Tools (func) is then called to run the function app.

Note: A folder is automatically generated for the hello_world function containing a file named function.json that is used by the Azure Functions runtime to load the function (they are ignored in .gitnore).
Open the URL displayed on the screen (http://localhost:7071/api/hello_world) to run the function.
Ctrl-C to stop the app.

Deploy the app to Azure

Now that you’ve run the function app locally, it’s time to deploy it to Azure!

Configure some variables (examples are in bash):

region=centralus # any region where Linux Azure Functions are available
resourceGroupName=<resource_group_name>
functionAppName=<function_app_name>
storageName=<storage_name> # must be between 3 and 24 characters in length and may contain numbers and lowercase letters only.

If you are not authenticated with the Azure CLI, log in.
```
# Log in to the Azure CLI
az login
```
This might not work in some environments (e.g. Codespaces). Try az login --use-device-code instead.

Run these Azure CLI commands to create and configure the function app:

# Create resource group
az group create -l $region -n $resourceGroupName

# Create storage account needed by function app
az storage account create -n $storageName -l $region -g $resourceGroupName --sku Standard_LRS

# Create function app (also works on Windows)
az functionapp create -n $functionAppName --storage-account $storageName \
    --consumption-plan-location $region -g $resourceGroupName \
    --functions-version 3 --runtime dotnet --os-type Linux

Deploy the app:
```
denofunc publish $functionAppName
```
Prior to deployment, denofunc tool will download the Deno Linux binary matching your locally installed version of deno that is included with the deployment package.
The deployment output will print out the URL of the deployed function. Open to the URL to run your function.

🎉 Congratulations!

You’ve deployed your first Azure Functions app in Deno! 🦕

Disclaimer: This is a community open source project. No official support is provided by Microsoft.