As DevOps engineers, proficiency in Linux and Git-GitHub is essential for managing and deploying code efficiently. With the vast array of commands and functionalities these tools offer, having a well-organized cheat-sheet can be a game-changer. Today, I’m sharing a comprehensive cheat-sheet covering essential Linux commands, Git commands, and GitHub tips that every DevOps professional should have in their toolkit.

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Linux Commands

File & Directory Management

• ls – List directory contents.

• cd [directory] – Change the current directory.

• pwd – Print working directory.

• mkdir [directory] – Create a new directory.

• rmdir [directory] – Remove an empty directory.

• rm [file] – Remove a file.

• cp [source] [destination] – Copy files or directories.

• mv [source] [destination] – Move or rename files or directories.

• touch [file] – Create an empty file or update the timestamp of an existing file.

File Viewing & Editing

• cat [file] – Concatenate and display file content.

• less [file] – View file content page by page.

• head [file] – Display the first 10 lines of a file.

• tail [file] – Display the last 10 lines of a file.

• nano [file] – Edit a file using the Nano text editor.

• vim [file] – Edit a file using the Vim text editor.

Permissions & Ownership

• chmod [permissions] [file] – Change file permissions.

• chown [owner]:[group] [file] – Change file owner and group.

• ls -l – List files with detailed information including permissions and ownership.

System Monitoring & Management

• top – Display active processes.

• ps aux – List all running processes.

• df -h – Display disk space usage.

• du -sh [directory] – Display disk usage of a directory.

• free -h – Display memory usage.

• uptime – Show system uptime and load averages.

Git Commands

Basic Commands

• git init – Initialize a new Git repository.

• git clone [url] – Clone a repository from a URL.

• git add [file] – Add a file to the staging area.

• git commit -m "[message]" – Commit changes with a message.

• git status – Show the status of changes.

• git log – Display commit history.

Branching & Merging

• git branch – List all branches.

• git branch [branch_name] – Create a new branch.

• git checkout [branch_name] – Switch to a branch.

• git merge [branch_name] – Merge a branch into the current branch.

• git rebase [branch_name] – Rebase the current branch onto another branch.

Stashing

• git stash – Temporarily save changes without committing.

• git stash pop – Apply stashed changes and remove them from the stash.

• git stash list – List all stashed changes.

• git stash drop – Remove a specific stash.

• git stash clear – Remove all stashes.

Cherry-Picking

• git cherry-pick [commit_hash] – Apply a specific commit from another branch.

Conflict Resolution

• git status – Show files with conflicts.

• git diff – Show differences between conflicting versions.

• git add [file] – Stage resolved files for commit.

GitHub Tips

Repository Management

• Create a Repository: Click "New" on GitHub and follow the prompts.

• Fork a Repository: Click "Fork" on the top-right of the repository page.

• Clone a Repository: Use git clone [url] to copy a repository locally.

Collaboration

• Pull Requests: Create a pull request to propose changes. Review and discuss before merging.

• Issues: Use GitHub Issues to track bugs, tasks, and feature requests.

• Wiki: Utilize the GitHub Wiki for project documentation.

Branch Protection

• Enable Branch Protection: Prevent force-pushes and require pull request reviews before merging.

GitHub Actions

• Set Up CI/CD: Create workflows using .github/workflows to automate build, test, and deployment processes.Linux Commands