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Important

Hobknob is deprecated and no longer actively supported.

If you are a contributor willing to take this project over then please get in touch via search-experience@opentable.com

hobknob-client-net

A .net client library for Hobknob

Installation

Either use the Nuget user interface in Visual Studio, or type the following in to a compatible prompt:

Install-package hobknob-client-net

Usage

var etcdHost = "localhost";
var etcdPort = 4001;
var applicationName = "radApp";
var cacheUpdateInterval = TimeSpan.FromSeconds(180);
EventHandler<CacheUpdateFailedArgs> cacheUpdateFailed = (o, args) => { throw args.Exception; }; 

var client = new HobknobClientFactory().Create(etcdHost, etcdPort, applicationName, cacheUpdateInterval, cacheUpdateFailed);

var toggleValue1 = client.GetOrDefault("Feature1", true); // Feature1 is false => false
var toggleValue2 = client.GetOrDefault("Feature2", true); // Feature2 does not exist => true

var toggleValue3 = client.GetOrDefault("DomainFeature1", "com", true); // Feature1/com exists => false
var toggleValue4 = client.GetOrDefault("DomainFeature1", "couk", true); // Feature1/couk does not exist => true

var allToggles = client.GetAll();

API

HobknobClientFactory().Create(string etcdHost, int etcdPort, string applicationName, TimeSpan cacheUpdateInterval)

Creates a new feature toggle client.

• etcdHost the host of the Etcd instance
• etcdPort the port of the Etcd instance
• applicationName the name of the application used to find feature toggles
• cacheUpdateInterval interval for the cache update, which loads all the applications toggles into memory
• cacheUpdateFailed delegate called whenever there is issue updating local hobknob cache. Must not be null for your own good.

client.GetOrDefault(string featureName, bool defaultValue)

Gets the boolean value of a simple feature toggle if it exists, otherwise return the default value

• featureName the name of the feature, used with the application name to get the feature toggle value
• defaultValue the value to return if the feature does not exist

var featureToggleValue = client.GetOrDefault("feature1", false);

client.GetOrDefault(string featureName, string toggleName, bool defaultValue)

Gets the boolean value of a multi feature toggle if it exists, otherwise return the default value

• featureName the name of the feature
• toggleName the name of the toggle (used when dealing with multi-features, e.g. Feature1/com)
• defaultValue the value to return if the feature toggle does not exist

var featureToggleValueForCom = client.GetOrDefault("DomainFeature1", "com", false);

client.GetAll()

Gets the values for all features for the application

var allToggles = client.GetAll();

client.CacheUpdated

An event which is raised on each cache update

client.CacheUpdated += (sender, eventArgs) => { console.Write("Updated"); }

client.CacheUpdateFailed

An event which is raised when there is an error updating the cache. This is the same event as the one that is registered in Create method.

client.CacheUpdateFailed += (sender, eventArgs) => { console.Write(eventArgs.Exception.ToString()); }

Building, testing and packaging from source

This project uses Docker Compose to build, test and create a Nuget package. Run the following in the command line:

docker-compose up --build --abort-on-container-exit

Publishing package to Nuget

The grunt plug-in grunt-nuget is used to package and publish nuget packages. To publish this package, run the following:

grunt build
grunt nugetpush:dist

Notes:

1. The version number in the HobknobClientNet.nuspec file must be incremented on each publish.
2. You must specify a user auth key to publish to Nuget (see https://github.com/spatools/grunt-nuget/wiki/Key-Options)

Etcd

Feature toggles are stored in Etcd using the following convention: http://host:port/v2/keys/v1/toggles/applicationName/featureName[/toggleName]