Integrate Azure Function

Article
10/12/2023

Introduction

This tutorial provides detailed guidance on how to set up an Azure Function to receive user-related information. Setting up an Azure Function is highly recommended. It helps to avoid hard-coding application parameters in the Contoso app (such as user ID and user token). This information is highly confidential. More importantly, we refresh user tokens periodically on the backend. Hard-coding the user ID and token combination requires editing the value after every refresh.

Prerequisites

Before you get started, make sure to:

Create an Azure account with an active subscription. For details, see Create an account for free.
Install Visual Studio Code.

Setting up functions

Install the Azure Function extension in Visual Studio Code. You can install it from Visual Studio Code's plugin browser or by following this link
Set up a local Azure Function app by following this link. We need to create a local function using the HTTP trigger template in JavaScript.
Install Azure Communication Services libraries. We'll use the Identity library to generate User Access Tokens. Run the npm install command in your local Azure Function app directory, to install the Azure Communication Services Identity SDK for JavaScript.

    npm install @azure/communication-identity --save

Modify the index.js file so it looks like the code below:

    const { CommunicationIdentityClient } = require('@azure/communication-identity');
    const connectionString = '<your_connection_string>'
    const acsEndpoint = "<your_ACS_endpoint>"
    
    module.exports = async function (context, req) {
        let tokenClient = new CommunicationIdentityClient(connectionString);
    
        const userIDHolder = await tokenClient.createUser();
        const userId = userIDHolder.communicationUserId
    
        const userToken = await (await tokenClient.getToken(userIDHolder, ["chat"])).token;
    
        context.res = {
            body: {
                acsEndpoint,
                userId,
                userToken
            }
        };
    }

Explanation to code above: The first line import the interface for the CommunicationIdentityClient. The connection string in the second line can be found in your Azure Communication Services resource in the Azure portal. The ACSEndpoint is the URL of the Azure Communication Services resource that was created.

Open the local Azure Function folder in Visual Studio Code. Open the index.js and run the local Azure Function. A local Azure Function endpoint will be created and printed in the terminal. The printed message looks similar to:

Functions:
HttpTrigger1: [GET,POST] http://localhost:7071/api/HttpTrigger1

Open the link in a browser. The result will be similar to this example:

    {
      "acsEndpoint": "<Azure Function endpoint>",
      "userId": "8:acs:a636364c-c565-435d-9818-95247f8a1471_00000014-f43f-b90f-9f3b-8e3a0d00c5d9",
      "userToken": "eyJhbGciOiJSUzI1NiIsImtpZCI6IjEwNiIsIng1dCI6Im9QMWFxQnlfR3hZU3pSaXhuQ25zdE5PU2p2cyIsInR5cCI6IkpXVCJ9.eyJza3lwZWlkIjoiYWNzOmE2MzYzNjRjLWM1NjUtNDM1ZC05ODE4LTk1MjQ3ZjhhMTQ3MV8wMDAwMDAxNC1mNDNmLWI5MGYtOWYzYi04ZTNhMGQwMGM1ZDkiLCJzY3AiOjE3OTIsImNzaSI6IjE2Njc4NjI3NjIiLCJleHAiOjE2Njc5NDkxNjIsImFjc1Njb3BlIjoiY2hhdCIsInJlc291cmNlSWQiOiJhNjM2MzY0Yy1jNTY1LTQzNWQtOTgxOC05NTI0N2Y4YTE0NzEiLCJyZXNvdXJjZUxvY2F0aW9uIjoidW5pdGVkc3RhdGVzIiwiaWF0IjoxNjY3ODYyNzYyfQ.t-WpaUUmLJaD0V2vgn3M5EKdJUQ_JnR2jnBUZq3J0zMADTnFss6TNHMIQ-Zvsumwy14T1rpw-1FMjR-zz2icxo_mcTEM6hG77gHzEgMR4ClGuE1uRN7O4-326ql5MDixczFeIvIG8s9kAeJQl8N9YjulvRkGS_JZaqMs2T8Mu7qzdIOiXxxlmcl0HeplxLaW59ICF_M4VPgUYFb4PWMRqLXWjKyQ_WhiaDC3FvhpE_Bdb5U1eQXDw793V1_CRyx9jMuOB8Ao7DzqLBQEhgNN3A9jfEvIE3gdwafpBWlQEdw-Uuf2p1_xzvr0Akf3ziWUsVXb9pxNlQQCc19ztl3MIQ"
    }

Deploy the local function to the cloud. More details can be found in this documentation.
Test the deployed Azure Function. First, find your Azure Function in the Azure portal. Then, use the "Get Function URL" button to get the Azure Function endpoint. The result you see should be similar to what was shown in step 5. The Azure Function endpoint will be used in the app for initializing application parameters.
Implement UserTokenClient, which is used to call the target Azure Function resource and obtain the Azure Communication Services endpoint, user ID and user token from the returned JSON object. Refer to the sample app for usage.

Troubleshooting guide

If the Azure Function extension failed to deploy the local function to the Azure cloud, it's likely due to the version of Visual Studio Code and the Azure Function extension being used having a bug. This version combination has been tested to work: Visual Studio Code version 1.68.1 and Azure Function extension version 1.2.1.
The place to initialize application constants is tricky but important. Double check the chat Android quick-start. More specifically, the highlight note in the section "Set up application constants", and compare with the sample app of the version you are consuming.

(Optional) secure the Azure Function endpoint

For demonstration purposes, this sample uses a publicly accessible endpoint by default to fetch an Azure Communication Services token. For production scenarios, one option is to use your own secured endpoint to provision your own tokens.

With extra configuration, this sample supports connecting to a Microsoft Entra protected endpoint so that user log is required for the app to fetch an Azure Communication Services token. The user will be required to sign in with Microsoft account to access the app. This setup increases the security level while users are required to log in. Decide whether to enable it based on the use cases.

Note that we currently don't support Microsoft Entra ID in sample code. Follow the links below to enable it in your app and Azure Function:

Configure your App Service or Azure Functions app to use Microsoft Entra ID log in.