Plan Branches (Git & Dev Tools)

Title: Mastering Branch Management with Bamboo - Plan Branches (Git & Dev Tools)

Why This Matters

Plan branches are an essential part of streamlining the development workflow, allowing teams to manage multiple features and bug fixes concurrently. By understanding how to effectively use plan branches in Bamboo, you can save time, reduce conflicts, and collaborate more efficiently with your team. In this lesson, we'll delve into the intricacies of using plan branches in Bamboo, a popular continuous integration and delivery tool by Atlassian.

Prerequisites

To follow along with this tutorial, you should have:

1. A basic understanding of Git version control system
2. Familiarity with Bamboo and its installation
3. A working repository containing multiple branches
4. Access to the Bamboo server with appropriate permissions
5. A good grasp of common command-line Git operations

Core Concept

Plan branches allow you to represent a branch in your version control repository within Bamboo. They use the same build configuration as your plan, making it easy to automatically build and test new branches. This practice is known as feature branching, where developers can work on isolated features or bug fixes before merging them back into mainline development.

Creating a Plan Branch

To create a plan branch in Bamboo:

1. Navigate to the "Plans" section and select your desired plan.
2. Click on the "Create Child Plan" button located at the top of the page.
3. Choose the branch you want to create a plan for from the dropdown menu labeled "Branch or tag."
4. Configure any necessary options, such as build triggers, artifact handlers, or custom variables.
5. Save the new plan by clicking on the "Create" button at the bottom of the page.

Now, whenever you push changes to that specific branch, Bamboo will automatically build and test it using the same configuration as your parent plan.

Managing Plan Branches

You have the flexibility to individually configure branch plans, allowing you to override the parent plan's settings if required. Additionally, any new branches created in the repository can be automatically built and tested, while branches deleted from the repository can be deleted automatically from Bamboo according to your settings.

Automatically Merging Changes

Optionally, changes from the feature branch can be automatically merged back to the master (e.g., trunk, default, or mainline branch) when the build succeeds. This helps keep your mainline development branch up-to-date and reduces the risk of conflicts during merges.

Working with Branch Divergence

Bamboo handles branch divergence by comparing the commit history between the parent plan and the branch plan. If there are any differences, Bamboo will build the latest version of the branch. This ensures that your builds always reflect the current state of the branch, regardless of any changes made to the parent plan.

Worked Example

Let's walk through an example where we create a new feature branch, make some changes, and automatically merge them back into our mainline development branch using Bamboo.

1. Start by creating a new feature branch in your repository:

git checkout -b my-feature-branch origin/my-feature-branch

1. Make the necessary changes to your codebase on the my-feature-branch.
2. Commit and push those changes to the remote repository:

git add .
git commit -m "Adding new feature"
git push origin my-feature-branch

1. In Bamboo, navigate to your parent plan and click on the "Create Child Plan" button.
2. Choose my-feature-branch from the dropdown menu labeled "Branch or tag."
3. Configure any necessary options, such as build triggers, artifact handlers, or custom variables.
4. Save the new plan by clicking on the "Create" button at the bottom of the page.
5. Once you push changes to the branch, Bamboo will automatically build and test it using the same configuration as your parent plan. If the build succeeds, the changes will be merged back into your mainline development branch according to your settings (manual merge or automatic merge).

Common Mistakes

1. Not configuring individual branch plans: Remember to configure each branch plan separately if necessary, as this allows you to override the parent plan's settings.
2. Ignoring branch divergence: Bamboo handles branch divergence automatically, but it's essential to understand how it works and ensure that your builds always reflect the current state of the branch.
3. Not merging changes back to mainline development: If you want to keep your mainline development branch up-to-date, make sure to enable automatic merges for your feature branches and configure them appropriately.
4. Overlooking build failures: If a build fails on a branch, investigate the cause and address any issues before merging changes back into mainline development.
5. Not deleting deleted branches in Bamboo: Make sure that your settings are configured to automatically delete branches from Bamboo when they are deleted from the repository.
6. Build configuration inconsistencies: Ensure that the build configurations for parent and child plans are consistent, as any differences can lead to unexpected results.
7. Not testing thoroughly: It's crucial to test your feature branch thoroughly before merging it back into mainline development to avoid introducing bugs or conflicts.

Practice Questions

1. What is feature branching, and why is it useful in a continuous integration environment?
2. How can you create a plan branch for a specific Git branch in Bamboo?
3. What happens when there are differences between the commit history of a parent plan and its child plan in Bamboo?
4. How can you automatically merge changes from a feature branch back into your mainline development branch using Bamboo?
5. Why is it essential to configure individual branch plans in Bamboo, and what settings can be overridden if necessary?
6. What are some common mistakes when working with plan branches in Bamboo, and how can they be avoided?
7. How can you ensure that the build configurations for parent and child plans are consistent in Bamboo?
8. Why is it crucial to test your feature branch thoroughly before merging it back into mainline development?

FAQ

1. Why should I use plan branches in Bamboo?

Plan branches help you manage multiple features and bug fixes concurrently by automatically building and testing new branches using the same configuration as your parent plan. This improves collaboration, saves time, and reduces conflicts during merges.

1. Can I configure individual branch plans in Bamboo?

Yes, you can configure each branch plan separately if necessary, allowing you to override the parent plan's settings.

1. What happens when a build fails on a branch in Bamboo?

If a build fails on a branch, it will not be merged back into your mainline development branch until the issue is resolved and the build passes successfully.

1. How does Bamboo handle branch divergence?

Bamboo handles branch divergence by comparing the commit history between the parent plan and the branch plan. If there are any differences, Bamboo will build the latest version of the branch to ensure that your builds always reflect the current state of the branch.

1. Can I automatically merge changes from a feature branch back into my mainline development branch using Bamboo?

Yes, you can enable automatic merges for your feature branches in Bamboo, which will merge changes back into your mainline development branch when the build succeeds.

1. Why is it essential to test your feature branch thoroughly before merging it back into mainline development?

Testing your feature branch ensures that any changes made do not introduce bugs or conflicts, helping maintain a stable and functional codebase.

1. How can I ensure that the build configurations for parent and child plans are consistent in Bamboo?

Ensure that the build configurations for both parent and child plans are identical or have been designed to work together seamlessly. You may also want to consider creating a template plan to serve as a base for your feature branches.

1. What settings can be overridden when configuring individual branch plans in Bamboo?

You can override various settings, such as build triggers, artifact handlers, custom variables, and even the entire build configuration if necessary.