testtrack-cli

testtrack-cli

TestTrack Split Config Management

Provides the testtrack command line interface as part of Betterment's TestTrack open source split testing and feature gating platform.

The testtrack CLI has the following features:

• Provides an app-language-agnostic developer experience for configuring TestTrack splits from your shell alongside your app code.
• Manages TestTrack migrations representing those configuration changes within your application's codebase so that your split configs follow your code from development, through tests and into production via plugging testtrack migrate into your build/deploy pipeline.
• Provides a zero-config dependency-free simplified implementation of the TestTrack server REST API for developers to use when developing locally (or on a cloud VM/container if that's your cup of tea).

Getting started

1. Download/install testtrack CLI

Currently TestTrack binaries for linux and macOS are distributed via GitHub releases. We'll add a homebrew tap soon to assist in installing and daemonizing the server on macOS.

2. Initialize your project

From your app root directory run:

testtrack init_project

This will create a testtrack subdirectory in your app that will store migration and schema YAML files. Commit these files to your repository.

It will also create a ~/.testtrack directory that will hold your local server's assignment overrides (assignments.yml).

3. Set up your app name in .env

# [my_app_root]/.env
TESTTRACK_APP_NAME=my_app

This is the name that your app will use to authenticate with TestTrack server in production (and any other environments you support). Typically in a unirepo, this can be your app repo name.

4. Point your app's TestTrack client at the testtrack fake server for development

You'll be embedding the same app name as you used above into the URL, e.g. http://my_app@localhost:8297

5. Configure your application bootstrap scripts

You'll want to install the platform-appropriate testtrack binary and call testtrack schema link --force on each developer's machine. We recommend Scripts To Rule Them All as a pattern for bootstrapping app development environments for your team.

6. Wire up testtrack to your build/deploy pipeline

a. Set an ENV var named TESTTRACK_CLI_URL with your TestTrack app credentials, e.g.:

TESTTRACK_CLI_URL=https://my_app:my_super_secret_app_token@testtrack.mydomain.com

into your build/deploy pipeline via whatever secrets management solution you use (heroku secrets, sops, etc).

b. Make sure the platform-appropriate testtrack binary is installed in your build/deploy environment (e.g. Jenkins, GoCD)

c. Run testtrack migrate from your app root. For server-side apps, this is great to wire up to the same build pipeline phase where you'd apply database migrations for your app. For mobile or other client-side apps, you'll want to run it after tests have passed and before persisting your gold master build artifact.

7. Start creating splits!

By default, splits will default to 100% false:

testtrack create feature_gate my_new_feature_q2_2019_enabled

Use the --weights argument to specify custom variants and weights:

testtrack create experiment my_new_feature_q2_2019_experiment --weights "control: 50, treatment_a: 25, treatment_b: 25"

8. Retire splits

Once an experiment is finished or feature released, remove all references to split in code. Then, decide and retire split.

testtrack destroy split my_new_feature_q2_2019_enabled --decision=true

Run testtrack help for more documentation on how to configure splits and other TestTrack resources.

Happy TestTracking!

Additional Configuration

The following configuration options are available:

Split ownership

If you have a large organization, you may wish to tag ownership of splits to a specific team to help provide accountability for clean up. This is supported natively in test_track.

1. You must specify an ownership file. The default file exists at testtrack/owners.yml though that can be overwritten with the TESTTRACK_OWNERSHIP_FILE environment variable.
2. This file should contain a list of team names, one per line. Any sub-values of the key names will be ignored for the purposes of test track.
3. If the test track client is able to find this file, it will require an --owner flag be set when creating new splits and experiements.
4. This data will be passed to the test track server where it can be recorded on the split records

How to Contribute

We would love for you to contribute! Anything that benefits the majority of TestTrack users—from a documentation fix to an entirely new feature—is encouraged.

Before diving in, check our issue tracker and consider creating a new issue to get early feedback on your proposed change.

Suggested Workflow

• Fork the project and create a new branch for your contribution.
• Write your contribution (and any applicable test coverage).
• Make sure all tests pass (make test).
• Submit a pull request.

Some tips for those new to golang

• Set up your workspace according to go standards.
• For macOS and homebrew users, run brew bundle to install go itself.
• Build and run the CLI using go run testtrack/main.go.