@openfeature/flagd-provider

Server-Side flagd Provider

Flagd is a simple daemon for evaluating feature flags. It is designed to conform to OpenFeature schema for flag definitions. This repository and package provides the client code for interacting with it via the OpenFeature server-side JavaScript SDK.

Installation

$ npm install @openfeature/flagd-provider

Required peer dependencies

$ npm install @openfeature/js-sdk

Usage

The FlagdProvider supports multiple configuration options that determine now the SDK communicates with flagd. Options can be defined in the constructor or as environment variables, with constructor options having the highest precedence.

Available Options

Option name	Environment variable name	Type	Default	Values
host	FLAGD_HOST	string	localhost
port	FLAGD_PORT	number	8013
tls	FLAGD_TLS	boolean	false
socketPath	FLAGD_SOCKET_PATH	string	-
cache	FLAGD_CACHE	string	lru	lru,disabled
maxCacheSize	FLAGD_MAX_CACHE_SIZE	int	1000
maxEventStreamRetries	FLAGD_MAX_EVENT_STREAM_RETRIES	int	5

Example Using TCP

  OpenFeature.setProvider(new FlagdProvider({
      host: 'localhost',
      port: 8013,
  }))

Example Using a Unix Socket

  OpenFeature.setProvider(new FlagdProvider({
      socketPath: "/tmp/flagd.socks",
  }))

Supported Events

The flagd provider emits PROVIDER_READY, PROVIDER_ERROR and PROVIDER_CONFIGURATION_CHANGED events.

SDK event	Originating action in flagd
PROVIDER_READY	The streaming connection with flagd has been established.
PROVIDER_ERROR	The streaming connection with flagd has been broken.
PROVIDER_CONFIGURATION_CHANGED	A flag configuration (default value, targeting rule, etc) in flagd has changed.

For general information on events, see the official documentation.

Flag Metadata

Field	Type	Value
scope	string	"selector" set for the associated source in flagd

Building

Run nx package providers-flagd to build the library.

NOTE: Buf must be installed to build locally.

Running Unit Tests

Run nx test providers-flagd to execute the unit tests via Jest.