feature-toggle.client

https://www.nuget.org/packages/mhlabs.feature-toggle.client/

Setup

Environment variables

• ApiPathFormat: default: "/int-feature-flags/int/flags/{0}/{1}/false"
• ApiRequestTimeoutMilliseconds: default: 125
• CacheDurationInSeconds: default: 60

IServiceCollection

Extension methods look like this:

public static class ServiceCollectionExtensions
{
    /// Registers client with RetryLevel.Read and UseCircuitBreaker = true
    public static IServiceCollection AddFeatureToggleClient(this IServiceCollection services, string baseUrl)
    {
        return services.AddFeatureToggleClient(new HttpOptions 
        {
            BaseUrl = baseUrl,
            RetryLevel = RetryLevel.Read,
            UseCircuitBreaker = true
        });
    }
    public static IServiceCollection AddFeatureToggleClient(this IServiceCollection services, HttpOptions options)
    {
        services.AddSingleton<IFeatureToggleClient, FeatureToggleClient>();
        services.AddSingleton<IFeatureToggleConfiguration, FeatureToggleConfiguration>();
        services.AddSignedHttpClient<IFeatureToggleService, FeatureToggleService>(options);
        return services;
    }
}

With Base only + retries & circuit breaker

serviceCollection.AddFeatureToggleClient("https://api.feature-service.com");

With HttpOptions

var options = new HttpOptions ()
{
    BaseUrl = "https://api.feature-service.com",
    RetryLevel = RetryLevel.Read,
    UseCircuitBreaker = true
}

serviceCollection.AddFeatureToggleClient(options);

Usage

Retrieve flag for user

public class MyService
{   
    private readonly IFeatureToggleClient _client;
    private readonly IMyOldService _oldService;
    private readonly IMyNewService _newService;

    public MyService (IFeatureToggleClient client, IMyOldService oldService, IMyNewService newService)
    {
        _client = client;
        _oldService = oldService;
        _newService = newService;
    }

    public async Task<ServiceResponse> GetForMember(string userKey)
    {
        var flag = await _client.Get("ai-service.v2", userKey, false);

        return flag.Enabled ?
            await _newService.Get() :
            await _oldService.Get();
    }
}

Contract

public interface IFeatureToggleResponse
{
    bool Active { get; set; }
    string Error { get; set; }
    long TimeStamp { get; }
}