Day 27 · Git

Git Revert Some Changes

By Published Git / Linux~1h to complete

Technical Overview

In collaborative software development, mistakes occur—buggy code gets committed, config files get broken, or features get abandoned. To roll back changes safely, developers must choose between rewriting history or preserving it.

Git Revert vs. Git Reset

Understanding when to use git revert versus git reset is one of the most critical history management practices in Git:

Feature git revert (Safe / Public) git reset (Destructive / Local)
Operational Mechanism Applies the exact inverse of the targeted commit as a new commit at the tip of the branch. Moves the current branch pointer (HEAD) backward to a previous target commit.
History Effect Preserves history. No existing commits are deleted or modified. Rewrites history. Commits newer than the target are removed from the branch timeline.
Collaboration Impact Safe for shared/public branches. Since it only adds new commits, team members can pull the changes without conflicts. Dangerous for shared branches. Force pushing (git push --force) a reset branch diverges other developers' work, causing synchronization conflicts.
Working Directory Does not modify untracked or local uncommitted changes unless there is a conflict. Can discard local changes depending on flags (e.g. --hard discards, --soft keeps them in staging).

Common Revert Commands and Scenarios

  • Revert the Latest Commit (HEAD):
    git revert HEAD
    Undoes the changes introduced by the most recent commit on the active branch and automatically launches a text editor to write the commit message.
  • Revert a Specific Historic Commit:
    git revert <commit_hash>
    Applies inverse changes for a specific commit in the middle of your history. If the changes overlap with later work, Git will halt and ask you to resolve merge conflicts.
  • Revert Without Committing (--no-commit):
    git revert -n <commit_hash>
# Alternatively: git revert --no-commit HEAD
    Applies the inverse changes directly to your Working Directory and Staging Area (index) but does not create a commit. This allows you to inspect the changes or combine multiple reverts into a single commit.

This guide outlines the steps to log in to the Nautilus Storage Server, locate the designated repository, audit commit history, and execute a safe rollback by reverting the latest commit.

Infrastructure & Configuration Requirements

  • Target Host: Nautilus Storage Server (ststor01)
  • SSH User: natasha (or designated sudo user)
  • Local Repo Path: /usr/src/kodekloudrepos/cluster (or designated repository name)
  • Revert Target: The latest commit (HEAD)
  • Target Commit Message: revert cluster

Step-by-Step Implementation

Step 1: Connect to the Storage Server

From the Jump Host, SSH into the storage server:

ssh natasha@ststor01

Step 2: Navigate to the Repository

Change directory to the designated local git repository:

cd /usr/src/kodekloudrepos/cluster

Step 3: Inspect the Commit History

Display the recent commit log to identify the latest commit (HEAD) and view its description:

git log --oneline -n 5

Example history log showing the target commit at the top:

f3a8b2c (HEAD -> master) Add cluster configuration details
e8c3a1b Initial commit

Step 4: Revert the Latest Commit

Execute the revert command targeting the latest commit (HEAD):

git revert HEAD

Git Editor Prompt:

  1. Git will automatically launch the default text editor (usually vi or nano) populated with a default commit message (e.g., Revert "Add cluster configuration details").
  2. Delete the default text and enter the requested message:
    revert cluster
  3. Save the file and close the editor (in vi, press Esc, type :wq, and press Enter).

Expected terminal output upon saving:

[master 6d2fa4a] revert cluster
 1 file changed, 1 deletion(-)
 delete mode 100644 cluster_spec.json

Post-Deployment Verification

1. Inspect the Updated Commit History

Verify that a new revert commit has been added to the top of the branch history:

git log --oneline -n 5

Expected output:

6d2fa4a (HEAD -> master) revert cluster
f3a8b2c Add cluster configuration details
e8c3a1b Initial commit

The history shows that the target commit (f3a8b2c) remains in place, but the new commit (6d2fa4a) has effectively undone its changes.

2. Confirm Working Directory State

List the files in the directory to verify that the file introduced by the reverted commit (e.g., cluster_spec.json) has been deleted:

ls -lh

Log out of the Storage Server:

exit

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