Harness CF Ruby Server SDK
Table of Contents
Intro
Requirements
Quickstart
Further Reading
Build Instructions
Intro
Harness Feature Flags (FF) is a feature management solution that enables users to change the software’s functionality, without deploying new code. FF uses feature flags to hide code or behaviours without having to ship new versions of the software. A feature flag is like a powerful if statement.
- For more information, see https://harness.io/products/feature-flags/
- To read more, see https://ngdocs.harness.io/category/vjolt35atg-feature-flags
- To sign up, https://app.harness.io/auth/#/signup/
Requirements
Ruby 2.7 or newer (ruby –version)
Quickstart
The Feature Flag SDK provides a client that connects to the feature flag service, and fetches the value
of feature flags. The following section provides an example of how to install the SDK and initialize it from
an application.
This quickstart assumes you have followed the instructions to setup a Feature Flag project and have created a flag called harnessappdemodarkmode
and created a server API Key.
Install the SDK
Install the ruby SDK using gem
gem install ff-ruby-server-sdk
or by adding the following snippet to your project’s Gemfile
file:
gem "ff-ruby-server-sdk"
A Simple Example
Here is a complete example that will connect to the feature flag service and report the flag value every 10 seconds until the connection is closed.
Any time a flag is toggled from the feature flag service you will receive the updated value.
require 'ff/ruby/server/sdk/api/config' require 'ff/ruby/server/sdk/dto/target' require 'ff/ruby/server/sdk/api/cf_client' require 'ff/ruby/server/sdk/api/config_builder' require "logger" require "securerandom" $stdout.sync = true logger = Logger.new $stdout # API Key apiKey = ENV['FF_API_KEY'] || 'changeme' # Flag Name flagName = ENV['FF_FLAG_NAME'] || 'harnessappdemodarkmode' # Create a Feature Flag Client and wait for it to initialize client = CfClient.instance client.init(apiKey, ConfigBuilder.new.logger(logger).build) client.wait_for_initialization # Create a target (different targets can get different results based on rules. This include a custom attribute 'location') target = Target.new("RubySDK", identifier="rubysdk", attributes={"location": "emea"}) # Loop forever reporting the state of the flag loop do result = client.bool_variation(flagName, target, false) logger.info "Flag variation: #{result}" sleep 10 end client.close
Running the example
# Install the deps gem install ff-ruby-server-sdk typhoeus # Set your API Key export FF_API_KEY= # Run the example ruby ./example/getting_started/getting_started.rb
Running with docker
If you don’t have the right version of ruby installed locally, or don’t want to install the dependencies you can
use docker to quickly get started
# Install the package docker run -v $(pwd):/app -w /app -e FF_API_KEY=$FF_API_KEY ruby:2.7-buster gem install --install-dir ./gems ff-ruby-server-sdk typhoeus # Run the script docker run -v $(pwd):/app -w /app -e FF_API_KEY=$FF_API_KEY -e GEM_HOME=/app/gems ruby:2.7-buster ruby ./example/getting_started/getting_started.rb
Additional Reading
Further examples and config options are in the further reading section:
Harness is a feature management platform that helps teams to build better software and to
test features quicker.