- Git Intro
- Git Setup
- Git Basics
- Merge Request
- Merge Conflicts
- Revert and Unstage
- Instructor Notes
- Records changes to a file
- Maintains history of changes
- Disaster Recovery
- Types of VCS: Local, Centralized and Distributed
- 1991-2002: The Linux kernel was being maintaned by sharing archived files and patches.
- 2002: The Linux kernel project began using a DVCS called BitKeeper
- 2005: BitKeeper revoked the free-of-charge status and Git was created
- Distributed Version Control System
- Great branching model that adapts well to most workflows
- Fast and reliable
- Keeps a complete history
- Disaster recovery friendly
- Open Source
- Use the tools at your disposal when you get stuck.
git help <command>command
- Use Google (i.e. StackOverflow, Google groups)
- Read documentation at https://git-scm.com
- Windows: Install 'Git for Windows'
- Mac: Type
gitin the Terminal application.
- If it's not installed, it will prompt you to install it.
sudo apt-get install git-all
- Red Hat
sudo yum install git-all
- One-time configuration of the Git client:
git config --global user.name "Your Name" git config --global user.email firstname.lastname@example.org
- If you don't use the global flag you can setup a different author for each project
- Check settings with:
git config --global --list
- You might want or be required to use an SSH key.
- Instructions: SSH
- Choose a directory on you machine easy to access
- Create a workspace or development directory
- This is where we'll be working and adding content
mkdir ~/development cd ~/development -or- mkdir ~/workspace cd ~/workspace
- Untracked files
- New files that Git has not been told to track previously.
- Working area (Workspace)
- Files that have been modified but are not committed.
- Staging area (Index)
- Modified files that have been marked to go in the next commit.
- Hosted repository on a shared server
- GitLab is an application to code, test and deploy.
- Provides repository management with access controls, code reviews, issue tracking, Merge Requests, and other features.
- The hosted version of GitLab is gitlab.com
- Sign in into your gitlab.com account
- Create a project
- Choose to import from 'Any Repo by URL' and use https://gitlab.com/gitlab-org/training-examples.git
- On your machine clone the
- See it listed as a changed file (working area)
- View the differences
- Stage the file
- Push the commit to the remote
- View the git log
# Edit `edit_this_file.rb` git status git diff git add <file> git commit -m 'My change' git push origin master git log
- Create a new feature branch called
bugs.rband remove all the bugs.
git checkout -b squash_some_bugs # Edit `bugs.rb` git status git add bugs.rb git commit -m 'Fix some buggy code' git push origin squash_some_bugs
- When you want feedback create a merge request
- Target is the ‘default’ branch (usually master)
- Assign or mention the person you would like to review
WIPto the title if it's a work in progress
- When accepting, always delete the branch
- Anyone can comment, not just the assignee
- Push corrections to the same branch
- Create your first merge request
- Use the blue button in the activity feed
- View the diff (changes) and leave a comment
- Push a new commit to the same branch
- Review the changes again and notice the update
- Merge requests are a time for feedback and collaboration
- Giving feedback is hard
- Be as kind as possible
- Receiving feedback is hard
- Be as receptive as possible
- Feedback is about the best code, not the person. You are not your code
- Feedback and Collaboration
- Review the Thoughtbot code-review guide for suggestions to follow when reviewing merge requests:Thoughtbot
- See GitLab merge requests for examples: Merge Requests
- Happen often
- Learning to fix conflicts is hard
- Practice makes perfect
- Force push after fixing conflicts. Be careful!
- Checkout a new branch and edit conflicts.rb. Add 'Line4' and 'Line5'.
- Commit and push
- Checkout master and edit conflicts.rb. Add 'Line6' and 'Line7' below 'Line3'.
- Commit and push to master
- Create a merge request and watch it fail
- Rebase our new branch with master
- Fix conflicts on the conflicts.rb file.
- Stage the file and continue rebasing
- Force push the changes
- Finally continue with the Merge Request
git checkout -b conflicts_branch # vi conflicts.rb # Add 'Line4' and 'Line5' git commit -am "add line4 and line5" git push origin conflicts_branch git checkout master # vi conflicts.rb # Add 'Line6' and 'Line7' git commit -am "add line6 and line7" git push origin master
Create a merge request on the GitLab web UI. You'll see a conflict warning.
git checkout conflicts_branch git fetch git rebase master # Fix conflicts by editing the files. git add conflicts.rb # No need to commit this file git rebase --continue # Remember that we have rewritten our commit history so we # need to force push so that our remote branch is restructured git push origin conflicts_branch -f
- When to use
git mergeand when to use
- Rebase when updating your branch with master
- Merge when bringing changes from feature to master
- Reference: https://www.atlassian.com/git/tutorials/merging-vs-rebasing/
To remove files from stage use reset HEAD. Where HEAD is the last commit of the current branch:
git reset HEAD <file>
This will unstage the file but maintain the modifications. To revert the file back to the state it was in before the changes we can use:
git checkout -- <file>
To remove a file from disk and repo use 'git rm' and to rm a dir use the '-r' flag:
git rm '*.txt' git rm -r <dirname>
If we want to remove a file from the repository but keep it on disk, say we forgot to add it to our .gitignore file then use
git rm <filename> --cache
Undo last commit putting everything back into the staging area:
git reset --soft HEAD^
Add files and change message with:
git commit --amend -m "New Message"
Undo last and remove changes
git reset --hard HEAD^
Same as last one but for two commits back:
git reset --hard HEAD^^
Don't reset after pushing
- Edit file again 'edit_this_file.rb'
- Check status
- Add and commit with wrong message
- Check log
- Amend commit
- Check log
- Soft reset
- Check log
- Pull for updates
- Push changes
# Change file edit_this_file.rb git status git commit -am "kjkfjkg" git log git commit --amend -m "New comment added" git log git reset --soft HEAD^ git log git pull origin master git push origin master
git revert vs git reset
Reset removes the commit while revert removes the changes but leaves the commit
Revert is safer considering we can revert a revert
# Changed file git commit -am "bug introduced" git revert HEAD # New commit created reverting changes # Now we want to re apply the reverted commit git log # take hash from the revert commit git revert <rev commit hash> # reverted commit is back (new commit created again)
- Local VCS was used with a filesystem or a simple db.
- Centralized VCS such as Subversion includes collaboration but still is prone to data loss as the main server is the single point of failure.
- Distributed VCS enables the team to have a complete copy of the project and work with little dependency to the main server. In case of a main server failing the project can be recovered by any of the latest copies from the team