Hand-on Demo – Release Branching for Continuous Delivery

Hand-on Demo – Release Branching for Continuous Delivery

The Release Branching model is useful when multiple versions of the software must be maintained simultaneously (e.g., active development on the next release while supporting an existing release). It balances structured development with Continuous Delivery (CD).

Release Branching Core Principles

1. main Branch:

   • Represents the latest production release.

   • Only updated via merges from release/ or hotfix/ branches.

2. release/ Branches:

   • Temporary branches used to finalize and stabilize a release.

   • Allow bug fixes or polishing before merging into main.

3. develop Branch (Optional): Used for integrating features before creating a release branch.

4. feature/ Branches: For feature development, based on develop (or main in simple setups).

5. hotfix/ Branches: For urgent fixes directly based on main.

Scenario: Managing a Release with Release Branching

1. Initial Setup

1. Branches:

   • main: Production-ready code.

   • release/: Used for finalizing releases.

   • develop (Optional): Active development branch.

2. Tools:

   • Git for version control.

   • CI/CD pipeline to test and deploy code.

2. Workflow Steps

Step 1: Feature Development

Develop features using feature/ branches based on develop:

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# Create a feature branch from develop
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git checkout develop
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git checkout -b feature/add-login-page
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# Make changes and commit
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echo "<h1>Login Page</h1>" > login.html
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git add login.html
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git commit -m "Add login page structure"
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# Push the branch and create a PR
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git push origin feature/add-login-page

After the feature is reviewed and approved, merge it into develop:

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git checkout develop
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git merge feature/add-login-page
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git push origin develop

Step 2: Create a Release Branch

When develop is ready for release:

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# Create a release branch from develop
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git checkout develop
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git checkout -b release/v1.0.0

Update version numbers or release-specific files:

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echo "v1.0.0" > version.txt
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git add version.txt
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git commit -m "Update version to v1.0.0"

Push the release branch for testing:

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git push origin release/v1.0.0

Step 3: Finalize the Release

• CI/CD runs staging tests on the release branch.

• Apply bug fixes directly to the release branch:

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echo "Fix issue #123" >> login.html
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git add login.html
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git commit -m "Fix issue #123 in release v1.0.0"
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git push origin release/v1.0.0

Step 4: Merge and Deploy

When the release is stable:

1. Merge the release branch into main:

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   git checkout main
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   git merge release/v1.0.0
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   git push origin main
   

2. Tag the release:

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   git tag -a v1.0.0 -m "Release v1.0.0"
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   git push origin v1.0.0
   

3. Merge the release branch back into develop (if applicable):

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   git checkout develop
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   git merge release/v1.0.0
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   git push origin develop
   

4. Delete the release branch:

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   git branch -d release/v1.0.0
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   git push origin --delete release/v1.0.0
   

The CI/CD pipeline deploys the main branch to production automatically.

Step 5: Handling Hotfixes

For urgent production fixes:

1. Create a hotfix branch from main:

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   git checkout main
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   git checkout -b hotfix/fix-login-bug
   

2. Fix the issue, commit, and push:

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   echo "Fix login bug in production" >> login.html
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   git add login.html
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   git commit -m "Fix login bug"
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   git push origin hotfix/fix-login-bug
   

3. Merge into main and develop:

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   git checkout main
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   git merge hotfix/fix-login-bug
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   git push origin main
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   git checkout develop
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   git merge hotfix/fix-login-bug
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   git push origin develop
   

4. Tag and delete the hotfix branch:

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   git tag -a v1.0.1 -m "Hotfix for login bug"
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   git push origin v1.0.1
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   git branch -d hotfix/fix-login-bug
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   git push origin --delete hotfix/fix-login-bug
   

Git Commands Summary

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# Feature development
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git checkout -b feature/add-login-page
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git commit -m "Add login page structure"
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git push origin feature/add-login-page
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git checkout develop
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git merge feature/add-login-page
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git push origin develop
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# Create a release branch
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git checkout -b release/v1.0.0
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git commit -m "Update version to v1.0.0"
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git push origin release/v1.0.0
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# Finalize release
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git checkout main
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git merge release/v1.0.0
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git tag -a v1.0.0 -m "Release v1.0.0"
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git push origin main
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git push origin v1.0.0
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git checkout develop
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git merge release/v1.0.0
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git branch -d release/v1.0.0
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git push origin --delete release/v1.0.0
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# Hotfix
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git checkout -b hotfix/fix-login-bug
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git commit -m "Fix login bug"
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git push origin hotfix/fix-login-bug
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git checkout main
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git merge hotfix/fix-login-bug
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git tag -a v1.0.1 -m "Hotfix for login bug"
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git push origin main
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git push origin v1.0.1
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git checkout develop
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git merge hotfix/fix-login-bug
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git branch -d hotfix/fix-login-bug
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git push origin --delete hotfix/fix-login-bug

Advantages of Release Branching for CD

1. Version Control: Allows simultaneous support for multiple software versions.

2. Stability: Finalizes the release in a dedicated branch, avoiding disruptions in develop.

3. Flexibility: Hotfix branches address urgent production issues efficiently.

Challenges

1. Slightly more complex than simpler models like GitHub Flow.

2. Requires disciplined merging and tagging processes to maintain branch hygiene.