Advance Git and GitHub for DevOps

1. Branching:

   • Git branching allows you to diverge from the main line of development and continue work without affecting the main codebase.

   • Creating a branch creates a pointer to a specific commit, allowing you to work on new features or fixes independently.

   • Once the work on a branch is complete, it can be merged back into the main branch.

2. Revert:

   • git revert creates a new commit that undoes a previous commit by applying the inverse of the changes. It's a safe way to undo changes without altering the repository's history.

   • It doesn't remove the commit; instead, it adds a new commit with the changes reverted.

3. Reset:

   • git reset is used to reset the current branch to a specific state. It can be a "soft," "mixed," or "hard" reset.

   • Soft reset moves the branch pointer to a previous commit, leaving changes staged.

   • Mixed reset moves the branch pointer and unstages the changes, but leaves them in the working directory.

   • Hard reset moves the branch pointer and discards all changes back to the specified commit.

4. Rebase:

   • git rebase integrates changes from one branch into another by moving or combining a sequence of commits to a new base commit.

   • It helps maintain a linear project history by placing the commits on top of the destination branch's tip.

   • Rebase is useful for a cleaner, more linear history but should be used cautiously when working on shared branches to avoid disrupting other collaborators.

5. Merge:

   • git merge combines changes from different branches into one. It creates a new commit that represents the combined changes of the merged branches.

   • Git can perform different types of merges, such as fast-forward merges or recursive merges, depending on the branch histories.

Absolutely! Here's a breakdown of Git commands and their application using sample code snippets.

1. Branching:

# Create a new branch
git branch new-feature

# Switch to the newly created branch
git checkout new-feature  # or "git switch new-feature" in Git versions 2.23+

# Make changes, commit them
git add .
git commit -m "Implementing new feature"

# Switch back to the main branch
git checkout main  # or "git switch main" in Git versions 2.23+

# Merge changes from the new feature branch into the main branch
git merge new-feature

2. Revert:

# Identify the commit to revert
git log  # Find the commit hash you want to revert

# Revert a specific commit
git revert <commit_hash>

3. Reset:

# Soft reset (moves the HEAD pointer, keeps changes in staging)
git reset --soft <commit_hash>

# Mixed reset (moves the HEAD pointer, unstages changes)
git reset --mixed <commit_hash>

# Hard reset (moves the HEAD pointer, discards changes)
git reset --hard <commit_hash>

4. Rebase:

# Start the rebase
git checkout new-feature
git rebase main

# Resolve any conflicts, if encountered
# Continue the rebase after conflicts are resolved
git rebase --continue

# Finish the rebase
git checkout main
git merge new-feature  # Fast-forward merge

5. Merge:

# Merge changes from a branch into the current branch (e.g., main)
git merge new-feature