Implement feature flags by using Azure App Configuration Feature Manager

Azure App Configuration is a managed service that provides a central repository for managing application settings. It allows you to externalize your application configuration and feature flags from code, making it easier to manage and update these settings without deploying new code.

Azure App Configuration Feature Manager is an extension of Azure App Configuration that specifically focuses on managing feature flags. With Feature Manager, you can define feature flags and their states, control their behavior, and manage feature toggles without changing your application code.

Setting up Azure App Configuration

Before we can start using Azure App Configuration Feature Manager, we need to set up an Azure App Configuration instance in the Azure portal. Follow these steps:

1. Open the Azure portal and create a new Azure App Configuration resource.
2. Provide a unique name, subscription, resource group, and location for the resource.
3. Once the resource is created, navigate to the App Configuration instance in the Azure portal.

We are now ready to define our feature flags.

Defining feature flags

To define a feature flag using Azure App Configuration Feature Manager, follow these steps:

1. In the Azure portal, open your App Configuration instance.
2. Under the “Settings” section, click on “Feature Management”.
3. Click on “New feature flag” to create a new feature flag.
4. Provide a unique name for the feature flag and select its state (enabled or disabled).
5. Optionally, you can add labels and target specific audiences for the feature flag.
6. Save the changes.

You have now defined a feature flag. Let’s explore how to integrate it into your application code.

Integrating feature flags in your application code

To integrate a feature flag in your application code, you need to install the appropriate NuGet package and add the necessary configuration settings. Follow these steps:

1. Open your application in Visual Studio.
2. Right-click on the project and select “Manage NuGet Packages”.
3. Search for “Microsoft.FeatureManagement.AspNetCore” and install the package.
4. Open the Startup.cs file and add the following code:

csharp
using Microsoft.FeatureManagement;

Inside the ConfigureServices method, add the following code to enable feature management:

csharp
services.AddFeatureManagement();

In your application code, inject the IFeatureManager interface and use it to check the state of your feature flag. For example:

csharp
private readonly IFeatureManager _featureManager;

public MyClass(IFeatureManager featureManager)
{
_featureManager = featureManager;
}

public void MyMethod()
{
if (_featureManager.IsEnabledAsync(“MyFeatureFlag”).Result)
{
// Feature flag is enabled, execute feature code
}
else
{
// Feature flag is disabled, execute fallback code
}
}

You have now integrated feature flags into your application code. Let’s see how to manage feature flags through the Azure portal.

Managing feature flags through Azure portal

Azure portal provides an intuitive interface for managing feature flags. Follow these steps to manage your feature flags:

1. Open your Azure App Configuration instance in the Azure portal.
2. Under the “Feature Management” section, click on “Feature flags”.
3. Select a feature flag to view and edit its details.
4. Use the toggle switch to enable or disable the feature flag.
5. Save the changes.

By managing feature flags through the Azure portal, you can easily control the behavior of your application without modifying the code.

Conclusion

In this article, we explored how to implement feature flags using Azure App Configuration Feature Manager. We learned how to set up Azure App Configuration, define feature flags, integrate them into application code, and manage them through the Azure portal.

By leveraging Azure App Configuration Feature Manager, you can effectively control the availability of features in your application, manage feature toggles, and easily roll out new features without redeployment.