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OpenFeature.Providers.GOFeatureFlag 1.1.0

GO Feature Flag - OpenFeature .NET provider

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This is the official OpenFeature .NET provider for accessing your feature flags with GO Feature Flag.

In conjuction with the OpenFeature SDK you will be able to evaluate your feature flags in your .NET applications.

For documentation related to flags management in GO Feature Flag, refer to the GO Feature Flag documentation website.

Functionalities:

• Manage the integration of the OpenFeature .NET SDK and GO Feature Flag relay-proxy.
• 2 types of evaluations available:
  • In process: fetch the flag configuration from the GO Feature Flag relay-proxy API and evaluate the flags directly in the provider.
  • Remote: Call the GO Feature Flag relay-proxy for each flag evaluation.
• Collect and send evaluation data to the GO Feature Flag relay-proxy for statistics and monitoring purposes.
• Support the OpenFeature tracking API to associate metrics or KPIs with feature flag evaluation contexts.

Dependency Setup

.NET Cli

dotnet add package OpenFeature.Providers.GOFeatureFlag

Package Manager

NuGet\Install-Package OpenFeature.Providers.GOFeatureFlag

Package Reference

<PackageReference Include="OpenFeature.Providers.GOFeatureFlag" />

Packet cli

paket add OpenFeature.Providers.GOFeatureFlag

Cake

// Install OpenFeature.Providers.GOFeatureFlag as a Cake Addin
#addin nuget:?package=OpenFeature.Providers.GOFeatureFlag

// Install OpenFeature.Providers.GOFeatureFlag as a Cake Tool
#tool nuget:?package=OpenFeature.Providers.GOFeatureFlag
```[GoFeatureFlagProviderOptions.cs](GoFeatureFlagProviderOptions.cs)

## Getting started

### Initialize the provider

GO Feature Flag provider needs to be created and then set in the global OpenFeatureAPI.

The only required option to create a `GoFeatureFlagProvider` is the endpoint to your GO Feature Flag relay-proxy
instance.

```csharp
using OpenFeature.Providers.GOFeatureFlag;

var options = new GoFeatureFlagProviderOptions { Endpoint = "https://gofeatureflag.example.com" };
var provider = new GoFeatureFlagProvider(options);

// Associate the provider with the OpenFeature API
await Api.Instance.SetProviderAsync("client_test", provider);

// Create a client to perform feature flag evaluations
var client = Api.Instance.GetClient("client_test");

// targetingKey is mandatory for each evaluation
var evaluationContext = EvaluationContext.Builder()
 .SetTargetingKey("d45e303a-38c2-11ed-a261-0242ac120002")
 .Set("email", "john.doe@gofeatureflag.org")
 .Build();

// Example of a boolean flag evaluation
var myFeatureFlag = await client.GetBooleanDetailsAsync("my-feature-flag", false, evaluationContext);

The evaluation context is the way for the client to specify contextual data that GO Feature Flag uses to evaluate the feature flags, it allows to define rules on the flag.

The targetingKey is mandatory for GO Feature Flag in order to evaluate the feature flag, it could be the id of a user, a session ID or anything you find relevant to use as identifier during the evaluation.

Configure the provider

You can configure the provider with several options to customize its behavior. The following options are available:

Evaluate a feature flag

The OpenFeature client is used to retrieve values for the current EvaluationContext. For example, retrieving a boolean value for the flag "my-flag":

var client = Api.Instance.GetClient("client_test");
var myFeatureFlag = await client.GetBooleanValueAsync("my-feature-flag", false, evaluationContext);

GO Feature Flag supports different all OpenFeature supported types of feature flags, it means that you can use all the accessor directly

// Boolean
client.GetBooleanValueAsync("my-flag", false, evaluationContext);

// String
client.GetStringValueAsync("my-flag", "default", evaluationContext);

// Integer
client.GetIntegerValueAsync("my-flag", 1, evaluationContext);

// Double
client.GetDoubleValueAsync("my-flag", 1.1, evaluationContext);

// Object
client.GetObjectValueAsync("my-flag", new Value("any value you want"), evaluationContext);

How it works

In process evaluation

When the provider is configured to use in process evaluation, it will fetch the flag configuration from the GO Feature Flag relay-proxy API and evaluate the flags directly in the provider.

The evaluation is done inside the provider using a webassembly module that is compiled from the GO Feature Flag source code. The wasm module is used to evaluate the flags, and the source code is available in the thomaspoignant/go-feature-flag repository.

The provider will call the GO Feature Flag relay-proxy API to fetch the flag configuration and then evaluate the flags using the wasm module.

Remote evaluation

When the provider is configured to use remote evaluation, it will call the GO Feature Flag relay-proxy for each flag evaluation.

It will perform an HTTP request to the GO Feature Flag relay-proxy API with the flag name and the evaluation context for each flag evaluation.

‼️ .NET Framework Compatibility

To be able to use the GO Feature Flag provider using the In Process mode, you need to use .NET Core SDK 3.0 SDK or later. If you are using an older version of the .NET Framework, you will only be able to use the remote evaluation mode.