How to GIT
We manage our development through issues tracking in Scipion GitHub project. + A nicer view of the Scipion issues is provided by Waffle.io
Configuration
Setup your name and email
git config --global user.name "Your Name"
git config --global user.email "your@email.domain"
Setup some aliases
git config --global alias.co checkout
git config --global alias.br branch
git config --global alias.ci commit
git config --global alias.st status
Branches
List all branches
git branch -a
Create a new branch and move to it:
git checkout -b NEW_BRANCH
Then you can publish it to origin:
git push -u origin NEW_BRANCH
Deleting a branch
Locally delete a branch
git branch -d OLD_BRANCH
This must be done in a different branch than OLD_BRANCH
The previous command does not allow to locally remove unless the OLD_BRANCH has been merged to another branch. If you want, anyway to locally remove the branch do
git branch -D oldBranch
To delete the branch remotely (after delete it locally):
git push origin :OLD_BRANCH
Everybody else has to “update” the list of branches in the origin, so that they also get it deleted:
git remote prune origin
Remote branch
To create a local branch at the status of a remote branch:
git pull
git checkout -b newlocalbranchname origin/remotebranchname
To create a branch and also set to track the remote branch:
git pull
git checkout -t origin/branch-name [-b newlocalbranch]
Submit a bugfix (with branch creation)
git checkout -b newBranchWithBugFix
git commit -m "Your comment" yourFiles
git push -u origin newBranchWithBugFix
Compare differences
To see differences between branch A and B:
git diff --name-status A..B
To see differences in a particular file between branch A and B:
git diff A B myFile
List the files that are changed between the local and the official repository
git diff origin/branch --name-only
List the files that are changed between two branches
git diff branch1 branch2 --name-only
Apply the differences from one branch into another
Let’s say that there is a file in branch2 with some differences with respect to branch 1. Then you want to take these differences and put them in branch 1. From branch 1, you must do
git diff branch1..branch2 yourFile > patchFile
git apply patchFile
If you run the git diff without file, then all changes between the two branches are dumped into the patchFile.
Stashing
Often, when you’ve been working on a part of your project, things end in a messy state. You want to switch branches for a while in order to work on something else. The problem is, you don’t want to do a commit of half-done work (just to be able to get back to this point later). The answer to this issue is the git stash command:
$ git stash
Now you can easily switch branches and do work elsewhere: your changes are stored on your stack. To see which stashes you’ve stored, you can use:
git stash list:
You can reapply the one you just stashed by using the command shown in the help output of the original stash command:
git stash pop
Merging
Undo a merge in the middle of it
Let’s say you are in the middle of a merging, and you regret from the changes you have already been introducing. Files that are not related to the merging conflicts are unaffected by this command.
git merge --abort
Avoid merge commits
If you want to avoid merge commits follow this [link]
In summary use:
git pull --rebase
or make it the default behavior in the config.
Commits
Checkout a commit by date
In case of looking for a commit by date, the repository can be moved by:
git co `git rev-list -n 1 --before="2011-06-21 13:37" master`
Check which commits have not been pushed yet
git log origin/master..master
Revert the changes introduced by a commit
If you have committed and pushed some changes, you may undo them by
git revert [commitHash]
Other useful commands
git grep
Look for specified patterns in the tracked files in the work tree.
git blame
Show what revision and author last modified each line of a file.
Git-Flow
Since January-2016, we started to follow the git-flow development methodology using git.
Summarizing, there are two main branches: master and devel. New branches should be opened from devel for each new feature that will be included in the next release. Feature-branches should be merged back through Pull Requests in GitHub to allow peer-review and discussions. Master branch should always contain a released status. When we are ready for a new release, we should create a release-branch from devel and only commit bug-fixes to it. When this release-branch is merged (also through Pull Request) to master, it means a new release that should be tagged in master.
The following image illustrates very well this workflow and a very nice explanation can be found [here].
= Other useful resources
[gitflow: A successful Git branching model]