Deployment triggers from tags in Git - Commands & Configuration

Introduction

Sometimes you want to start a deployment only when a specific version or milestone is ready. Using tags in git helps you mark these points and trigger deployments automatically when you create or push these tags.

When you want to deploy only stable versions marked by tags, not every commit.

When you release software versions like v1.0, v1.1 and want deployment to happen on these tags.

When your CI/CD pipeline listens for tags to start building and deploying your app.

When you want to keep your deployment history clean by deploying only tagged releases.

When you want to roll back easily by deploying a previous tag.

Commands

This command creates a new tag named v1.0 on the current commit to mark a release point.

Terminal

git tag v1.0

Expected Output

No output (command runs silently)

This pushes the tag v1.0 to the remote repository so that the deployment system can detect it.

Terminal

git push origin v1.0

Expected Output

To https://github.com/example/repo.git

 * [new tag]         v1.0 -> v1.0

Lists all tags in the local repository to verify that the tag was created.

Terminal

git tag

Expected Output

v1.0

Pushes all local tags to the remote repository at once, useful if you created multiple tags.

Terminal

git push --tags

Expected Output

To https://github.com/example/repo.git

 * [new tag]         v1.0 -> v1.0

→

--tags - Push all tags to remote

Key Concept

If you remember nothing else from this pattern, remember: creating and pushing tags lets your deployment system know exactly when to deploy specific versions.

Common Mistakes

Creating a tag locally but forgetting to push it to the remote repository.

The deployment system only sees tags on the remote, so it won't trigger deployment.

Always run 'git push origin <tagname>' or 'git push --tags' after creating tags.

Pushing tags before the commit is ready or tested.

This can trigger deployment of incomplete or broken code.

Make sure your code is tested and stable before tagging and pushing.

Using lightweight tags instead of annotated tags when your deployment system requires metadata.

Lightweight tags have no extra info like author or date, which some systems need.

Use 'git tag -a v1.0 -m "Release v1.0"' to create annotated tags if needed.

Summary

Create a tag to mark a specific commit for deployment.

Push the tag to the remote repository so deployment systems can detect it.

Use 'git tag' to list tags and verify creation.

Use 'git push --tags' to push all tags at once.

Practice

1. What is the main purpose of using tags in Git for deployment triggers?

easy

A. To merge multiple branches into one

B. To delete old branches automatically

C. To create new branches for development

D. To mark specific versions of code for deployment

Solution

1. Step 1: Understand what tags represent in Git

   Tags are labels that mark specific points in Git history, usually used for releases or versions.

2. Step 2: Connect tags to deployment triggers

   Deployment systems listen for tag pushes to know when to deploy a specific version of the code.

3. Final Answer:

   To mark specific versions of code for deployment -> Option D

4. Quick Check:

   Tags mark versions = C [OK]

Hint: Tags label versions for deployment triggers [OK]

Common Mistakes:

• Confusing tags with branches
• Thinking tags delete branches
• Assuming tags create new branches

2. Which Git command correctly creates a tag named v1.0 and pushes it to the remote repository?

easy

A. git create tag v1.0 && git push tags

B. git push tag v1.0

C. git tag v1.0 && git push origin v1.0

D. git tag create v1.0 && git push origin tags

Solution

1. Step 1: Identify the correct command to create a tag

   The command git tag v1.0 creates a tag named v1.0 locally.

2. Step 2: Identify how to push the tag to remote

   git push origin v1.0 pushes the specific tag to the remote repository.

3. Final Answer:

   git tag v1.0 && git push origin v1.0 -> Option C

4. Quick Check:

   Create tag + push tag = A [OK]

Hint: Use 'git tag' then 'git push origin tagname' [OK]

Common Mistakes:

• Using 'git push tag' which is invalid
• Trying 'git create tag' which is not a Git command
• Pushing 'tags' instead of specific tag name

3. Given this GitHub Actions snippet, what triggers the deployment workflow?

on:
  push:
    tags:
      - 'release-*'

medium

A. Any push of tags starting with 'release-'

B. Any push to branches named 'release-*'

C. Any push to any branch

D. Any push of tags named exactly 'release-*'

Solution

1. Step 1: Understand the trigger syntax

   The on.push.tags with pattern 'release-*' listens for tag pushes starting with 'release-'.

2. Step 2: Differentiate tags from branches

   This does not trigger on branches, only on tags matching the pattern.

3. Final Answer:

   Any push of tags starting with 'release-' -> Option A

4. Quick Check:

   Push tags matching pattern = A [OK]

Hint: Tags trigger with 'push.tags' and pattern [OK]

Common Mistakes:

• Confusing tags with branches in triggers
• Thinking exact tag name match is required
• Assuming all pushes trigger workflow

4. You set this in your GitHub Actions workflow:

on:
  push:
    tags:
      - 'v*'

But pushing tag release1 does NOT trigger the workflow. Why?

medium

A. The tag name does not match the pattern 'v*'

B. Tags cannot trigger workflows in GitHub Actions

C. The workflow file is missing from the repository

D. The push event only triggers on branches, not tags

Solution

1. Step 1: Analyze the tag pattern

   The pattern 'v*' matches tags starting exactly with 'v', like 'v1.0', but 'release1' starts with 'release', so it does not match.

2. Step 2: Confirm tag triggers work

   GitHub Actions supports tag push triggers, so the problem is pattern mismatch.

3. Final Answer:

   The tag name does not match the pattern 'v*' -> Option A

4. Quick Check:

   Pattern mismatch blocks trigger = B [OK]

Hint: Check tag name matches trigger pattern exactly [OK]

Common Mistakes:

• Assuming any tag triggers workflow
• Thinking tags can't trigger workflows
• Ignoring pattern matching rules

5. You want to deploy only when a tag matching deploy-* is pushed. Which GitHub Actions trigger configuration is correct?

hard

A. on:
push:
tags:
- 'release-*'

B. on:
push:
tags:
- 'deploy-*'

C. on:
tag_push:
pattern: 'deploy-*'

D. on:
push:
branches:
- 'deploy-*'

Solution

1. Step 1: Identify correct event for tag push

   The push event with tags key listens for tag pushes matching patterns.

2. Step 2: Match the pattern to desired tags

   The pattern 'deploy-*' matches tags starting with 'deploy-', exactly what is needed.

3. Step 3: Eliminate incorrect options

   on: push: branches: - 'deploy-*' listens to branches, not tags. on: tag_push: pattern: 'deploy-*' uses invalid syntax. on: push: tags: - 'release-*' matches wrong tag pattern.

4. Final Answer:

   on: push: tags: - 'deploy-*' -> Option B

5. Quick Check:

   Push tags with correct pattern = D [OK]

Hint: Use 'push.tags' with correct pattern for deployment triggers [OK]

Common Mistakes:

• Using branches instead of tags for deployment triggers
• Using invalid event names like 'tag_push'
• Mismatching tag patterns