Feature flags
Feature flags are a software development and delivery technique that allows software teams to enable and disable parts of a codebase at the flip of a switch. Feature flags enable a team to deliver new features to users rapidly but safely.
Feature flags also allow you to decouple code deployments from feature releases. You can make code changes in production while hiding those changes from users.
Feature flags and trunk-based development
Trunk-based development uses feature flags as the mechanism to manage new feature releases. Developers deploy incomplete features to production without releasing them to end users, which keeps branches short-lived and merges small.
End to end process:
- Create a short-lived feature branch with the feature flag off.
- Implement the feature through iterations of small, merged changes.
- Release the code continuously; turn the flag on when the business is ready.
- Retire the feature flag.
Agree before work begins whether a feature needs a flag, so that code can be deployed to production ahead of the business release, for example to allow time for staff training or for legislation to be announced. See continuous delivery.
Platform tooling
Services on the Cloud Native Platform use LaunchDarkly: see feature flags with LaunchDarkly for access, projects and environments.