Git

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Revision as of 18:20, 1 February 2017 by Andre (talk | contribs)

File:GitForArtists.jpg

Talk Git

  • What is Git? What do you imagine Git to be?
  • Who uses Git?
  • How is Git used?

art/design project using Git

install Git

https://git-scm.com/book/en/v2/Getting-Started-Installing-Git

https://git-scm.com/downloads

Mac

Git is installed when you install Xcode

to check if it is installed run in the command line:

git --version

If it responds with a version number, Git is installed

Start Git

To start using Git, you need:

  • a dedicated folder for you project, where all files and sub-folders of the project live
  • navigate with the command line to that folder: cd path/to/folder
  • initialize Git: git init

The last step with create a hidden .git/ folder where all the Git data will be stored.

3 Git moments

For local (in your computer) Git operations, there are 3 main moments:

  • working: editing files
  • stage: adding (tracking) files to git
  • commit: span-shooting the changes performed on files

Stage

Staging refers to the action of making files ready for commit.

  • git add when run for the 1st time on file or folder, it ask Git to start tracking it
    • on a file that is being tracked, but has since changed, it include those changes to be commited
    • There might be files you might not want to track and therefore you don't add them
  • git status overview or staged moment:
    • displays tracked and untracked files

Trick: If you wanna stage from files which Git is tracking run: git add -u

Commit

A commit is version of your project. When you complete some part of the work, you commit!

  • git commit -m "message about what happened in that commit" creates a version or commit of your project. A accompanying message describes what happen in that commit.
  • git log show the history of commits, where each commit is shows an author, date, message and hash (a long string of letter and numbers that identifies the commit)


Undoing things

unstage

Unstage, means bring added changes out or the stage moment. In other words, before commiting, the changes you made to a file, then git add that.file, can be undone by running:

git reset HEAD file.name

Warning: those changes will be lost!

checkout a specific commit

The state of files in a specific commit can be checked out using:

git checkout commit-hash

This command will detach the HEAD (like the reading head of a K7) from the latest commit. In other words, it will let you go back in time to a previous commit.

To keep it simple, you can't do much there, but look around, copy content from files and save them in new (untracked) files.

When you are done, you can return the head to the latest commit by running

git checkout master

reverts

Reverts the head to a previous commit: git revert commit-hash

But instead of erasing history, creates a new commit



resources

Git Cheatsheet

Git home

blog on Github Terms of Services


DAY 2: Remotes / collaboration


remote repositories

Git facilitates the coordination of contributions from different collaborators in a project.

Each contributor has a local repository, that is a 'clone' of the remote repository.


The remote repository acts as the central node from which all the users will receive - pull - and send - push contributions.


creating a remote

In pzwart1 the git server is located in /home/git/

With the repositories stored /home/git/git/

To create a remote, 1 person(normally the admin) start a remote (bare) repository to push and pull code to and from:

cd /home/git/git
mkdir null.git
cd null.git 
git init --bare

set remote & first push

(Note: This step only needs to be performed by the admin, whom will usually set a remote in the local repository).

Inside local folder null-local/ dir:

git remote add origin git@pzwart1.wdka.hro.nl:/home/git/git/null.git #add origin remote
git remote -v #view the existing remotes. Only origin remote was added
   origin	git@pzwart1.wdka.hro.nl:/home/git/git/null.git (fetch)
   origin	git@pzwart1.wdka.hro.nl:/home/git/git/null.git (push)

cloning the remote

To clone the remote git needs an authentication from its users, usually using ssh keys.

authentication

ssh key pairs (a public and private key) is an authentication method for clients to access servers through ssh. E.g. For my computer to ssh to pzwart1.

How do we go about doing that:

  • in our local computers we need to generate an ssh-key pair
  • in our local computer a plain text file ~/.ssh/id_rsa.pub stores contains our public key
  • we give our public key to the git admin,
  • the adim adds the public key to the git server's /home/git/.ssh/authorized_keys
  • we are ready to clone, push and pull to the remote.

clone

git clone git@pzwart1.wdka.hro.nl:/home/git/git/amazing_project.git