How do you handle hotfixes and feature toggles in a continuous delivery environment?

1 What are hotfixes and feature toggles?

Hotfixes are urgent patches that fix critical bugs or security issues in the production system. Feature toggles are switches that enable or disable certain features or functionalities in the codebase, without changing the code itself. Both hotfixes and feature toggles can help you manage changes and deployments in a continuous delivery environment, where you release software regularly and incrementally.

2 How to use hotfixes effectively?

Hotfixes should be used sparingly and only for urgent issues that affect the system's functionality or security. They should be applied to the production branch, which is the source of truth for the live system, and then merged back to the main development branch, where all the ongoing work is done. This way, you can avoid conflicts and inconsistencies between the branches. You should also test your hotfixes thoroughly before deploying them, and monitor their impact on the system's performance and stability.

3 How to use feature toggles wisely?

Feature toggles can help you control the release of new features or functionalities, without having to modify the codebase. You can use them to test and experiment with different versions of the system, to enable or disable features for different user segments or environments, or to gradually roll out or roll back changes. However, feature toggles also come with some drawbacks, such as increased complexity, technical debt, and configuration overhead. Therefore, it is important to use them strategically and follow best practices like defining clear and consistent naming conventions and rules for your feature toggles, documenting and communicating the purpose and status of each feature toggle, using feature toggles only for short-term or conditional changes, not for permanent or irreversible ones, removing obsolete or unused feature toggles as soon as possible, and automating and simplifying the management and deployment of feature toggles.

4 How to choose the right branching strategy?

The branching strategy is the way you organize and manage your codebase across different branches. It varies depending on the size, scope, complexity of the project, as well as the team's workflow and collaboration style. While there is no one-size-fits-all solution, some common branching strategies include trunk-based development, Git flow, and GitHub flow. Trunk-based development involves using a single main branch with short-lived feature branches or feature toggles to isolate and test new features, as well as hotfix branches to fix urgent issues in production. Git flow uses a main development branch for integration and testing, as well as a production branch for stable verified releases. Feature branches are used to develop new features, release branches to prepare releases, and hotfix branches to fix issues in production. GitHub flow relies on a single main branch with feature branches for development, pull requests for reviews and merges, and hotfixes or feature toggles for issue fixes or feature control in production.

5 How to align your branching strategy with your continuous delivery pipeline?

Your continuous delivery pipeline is the automated process that builds, tests, and deploys your code from the source repository to the production system. Therefore, it's important to have a branching strategy that supports and facilitates this pipeline. To do this, keep branches short-lived and focused to avoid merge conflicts. Additionally, integrate and test your code frequently and continuously, as this will help detect errors early on. Automated tools and scripts can also be used to manage and synchronize branches and deployments, as well as reduce human errors. Furthermore, use consistent and meaningful naming conventions and tags for branches and releases so they are easy to identify. Finally, review and document your branching strategy and pipeline regularly to ensure they meet project goals.