Azure Identity Plugin for Token Cache Persistence

Article
04/04/2023

This package provides a plugin to the Azure Identity library for JavaScript (@azure/identity) that enables persistent token caching. Token cache persistence allows the built-in token cache to persist across sessions using a secure storage system provided by the local operating system.

Source code | Samples

Getting started

import { useIdentityPlugin } from "@azure/identity";
import { cachePersistencePlugin } from "@azure/identity-cache-persistence";

useIdentityPlugin(cachePersistencePlugin);

Prerequisites

An Azure subscription.

Install the package

This package is designed to be used with Azure Identity for JavaScript. Install both @azure/identity and this package using npm:

$ npm install --save @azure/identity
$ npm install --save @azure/identity-cache-persistence

Supported Environments

Azure Identity plugins for JavaScript support stable (even numbered) versions of Node.js starting from v12. While the plugins may run in other Node versions, no support is guaranteed. @azure/identity-cache-persistence does not support browser environments.

Key concepts

If this is your first time using @azure/identity or the Microsoft identity platform (Azure Active Directory), we recommend that you read Using @azure/identity with Microsoft Identity Platform first. This document will give you a deeper understanding of the platform and how to configure your Azure account correctly.

Azure Identity Plugins

As of @azure/identity version 2.0.0, the Identity client library for JavaScript includes a plugin API. This package (@azure/identity-cache-persistence) exports a plugin object that you must pass as an argument to the top-level useIdentityPlugin function from the @azure/identity package. Enable token cache persistence in your program as follows:

import { useIdentityPlugin } from "@azure/identity";
import { cachePersistencePlugin } from "@azure/identity-cache-persistence";

useIdentityPlugin(cachePersistencePlugin);

After calling useIdentityPlugin, the persistent token cache plugin is registered to the @azure/identity package and will be available on all credentials that support persistent token caching (those that have tokenCachePersistenceOptions in their constructor options).

Examples

Once the plugin is registered, you can enable token cache persistence by passing tokenCachePersistenceOptions with an enabled property set to true to a credential constructor. In the following example, we use the DeviceCodeCredential, since persistent caching of its tokens allows you to skip the interactive device-code authentication flow if a cached token is available.

import { useIdentityPlugin, DeviceCodeCredential } from "@azure/identity";
import { cachePersistencePlugin } from "@azure/identity-cache-persistence";

useIdentityPlugin(cachePersistencePlugin);

async function main() {
  const credential = new DeviceCodeCredential({
    tokenCachePersistenceOptions: {
      enabled: true
    }
  });

  // We'll use the Microsoft Graph scope as an example
  const scope = "https://graph.microsoft.com/.default";

  // Print out part of the access token
  console.log((await credential.getToken(scope)).token.substr(0, 10), "...");
}

main().catch((error) => {
  console.error("An error occurred:", error);
  process.exit(1);
});

Troubleshooting

Logging

Enabling logging may help uncover useful information about failures. In order to see a log of HTTP requests and responses, set the AZURE_LOG_LEVEL environment variable to info. Alternatively, logging can be enabled at runtime by calling setLogLevel in the @azure/logger:

import { setLogLevel } from "@azure/logger";

setLogLevel("info");

Next steps

Provide Feedback

If you encounter bugs or have suggestions, please open an issue.

Contributing

If you'd like to contribute to this library, please read the contributing guide to learn more about how to build and test the code.

Impressions

Share via