Azure config source

npm install @radutils/config-builder-source-azure@beta

This library contains config sources for Azure App Configuration and Azure Key Vault compatible with @radutils/config-builder.

Usage

The app describes how to set up a production ready source and config builder. More examples can be found in the examples folder.

Azure App Configuration

The ConfigSourceAzureAppConfiguration provides a way to load configuration values from an associated App Configuration instance. It can also resolve referred values such as Key Vault references automatically.

There are two main ways to initialize this source. Through the static method createDefault (recommended) or directly as a new instance. CreateDefault works as long as you are logged in to an account in Azure CLI or PowerShell that has access to the App Configuration instance you wish to read from first.

// Read endpoint from an environment variable.
const endpoint = process.env["APPCONFIG_ENDPOINT"]

// Specify any labels to try in order, leave blank to use unlabelled value
const labels: string[] = []

// createDefault is recommended and should work for most scenarios.
ConfigSourceAzureAppConfiguration.createDefault({ endpoint, labels })

// Create a separate app configuration client directly.
const connectionString = "..."
const appConfigClient = new AppConfigurationClient(connectionString)

// Create a new direct instance where you must provide the client yourself.
new ConfigSourceAzureAppConfiguration({ client: appConfigClient })

Authorization

The library will use @azure/identity DefaultAzureCredentials for authorization. This is a multi-credential class that should work well for most situations including hosting the application in Azure. To use your own account you can log in through the Azure CLI or Azure PowerShell and your credentials should be recognized.

Optionally you can override the credential option or the entire client in the options when creating an instance of the source to provide your own authorization mechanism.

getFixedDefaultAzureCredential

A utility function that addresses a specific issue with the DefaultAzureCredential:

This function addresses a problem with the DefaultAzureCredential where a timeout value carries over from some older request causing a long delay when looking up key vault secrets. This is NOT intended as a permanent fix, but a workaround until there is a more "official" way to solve the problem. Ref: https://github.com/Azure/azure-sdk-for-js/issues/23017

This "fixed" credential is used in place of the DefaultAzureCredential when calling ConfigSourceAzureAppConfiguration.createDefault