FESA3 vs. git

Roadmap SVN to GIT Migration: 2020

Calendar Week	What	Contact	Status
until KW43	SVN repository synchronization	FESA software developers	TODO
KW 44	SVN repository read-only	ACO / IN	TODO
KW 44	Migration SVN repository -> GIT repository	T. Habermann	TODO
KW 45	FESA Eclipse Plug-In for Eclipse 2020-06	ACO / FEC	TODO

The version control system 'git' is supposed to replace the currently used SVN. The following issues may be considered when moving the FESA projects sources to another version control repository.

• keep the history when moving the sources
• find a suitable workflow for FESA FWK developers
• which git host? git.gsi.de or an ACC git solution?
• how to setup git for classes, deploy-units, drivers, tools?
• when to adapt the workflow for classes / deploy-units in the plug-in?
• how to stay in sync with CERN's sources?
• how to perform FESA releases?
• usage of git issue-tracker and wiki as well for documentation?

Possible workflow for FESA Class Developers

Switching from SVN to git

Eclipse 2020-06

• FESA Repository Preferences: configure user name and password, provide email adress
• Project Explorer: Select Project(s); Team > Disconnect (Check: Also delete the SVN meta-information from the file system)
• Project Explorer: Select Project(s); New FESA Eclipse Plug-In: FESA > Configure FESA Project for Repository
  • initialisation of local git repository
  • configuration of git ignore settings
  • all relevant files will be added to the index
  • configuration of user name, email adress and password according to the credentials in the FESA preferences
  • configuration of remote repository URL
  • commit to local git repository
  • push to remote repository
• Connect a project in the workspace to enable repository synchronization in Eclipse, solution 1:
  • Switch to 'Git' perspective
  • Button: Add an existing local Git repository to this view
  • Browse workspace and select FESA projects
• Connect a project in the workspace to enable repository synchronization in Eclipse, solution 2:
  • Select project > Team > Show in Repositories View
• Troubleshooting:
  • use context menu FESA > Configure FESA Project for Repository to apply required settings
  • use context menu Team > Synchronize Workspace to commit and push changes to local / remote repository

Command Line

Details: FESAGitMigrationSkript

Contact person for the FESA software source code migration 10/2020: T. Habermann

Structure

Local git Repository

<workspace>/<project>/.git

Remote git Repository

https://git.acc.gsi.de/fesa-classes/<project>.git

https://git.acc.gsi.de/fesa-deploy-units/<project>.git

https://git.acc.gsi.de/driver/<project>.git

Working with git

• commit locally, either working in feature branch or master branch directly; branch merging required
• push to remote once feature is considered ready
• during release: project has to be up-to-date and synchronized with the master branch, release branch should be created automatically

Git Cheat Sheet for FESA Projects

Topic	Command / Usage Examples	Description
Configuration
Configure user name	git config --global user.name "The Name"	Stores the user name in the git configuration.
Configure email adress	git config --global user.email t.name@gsi.de	Stores the email adress in the git configuration.
View configuration	git config --list	Displays the git configuration.
Setup of local Repository
	cd workspace/<FESAproject> git init	Creates hidden .git directory at project level (<FESAproject>/.git)
Status Check	git status	Displays the repository status (untracked, added, deleted files and folders)
Add files	git add <file> <file1> <file2>	Adds files to the staging area
Commit locally	git commit -m "commit message"	Commits staged files to the local repository
Branching and Merging
Create a branch and switch to the new branch	git checkout -b <issue-0815>	Creates the new branch issue-0815 and switches to the branch. Changes in the branch should be committed to the branch.
Merge branch into master (after add/commit)	git checkout master git merge <issue-0815>	Note: Requires the changes in the branch committed to the branch. Switches back to the master branch. Merges the changes in branch issue-0815 into the master branch.
Switch to master branch	git checkout master	Switches back to the master branch.
Tags
Create tag	git tag -a 1.2.3 -m "version 1.2.3"	Creates a tag named 1.2.3
View tags	git tag git show 1.2.3	Lists existing tags Shows details of tag 1.2.3
Pushing tag to remote repository	git push origin 1.2.3	By default tags are not pushed explicitely to the remote repository. This has to be done explicitely.
Deleting tags	git tag -d 1.2.3	Deletes the tag 1.2.3
Working with remote Repositories
Create remote repository at git.acc.gsi.de	See script createRemoteRepository.py.txt	Uses gittea REST API to create a project in the remote repository
Configure remote repository	git remote add origin https://git.acc.gsi.de/fesa-classes/<classname>.git git remote add origin https://git.acc.gsi.de/fesa-deploy-units/<duname>.git git remote add origin https://git.acc.gsi.de/fesa-drivers/<drivername>.git	Adds the URL for the remote repository.
Push to remote repository (after add/commit)	git push origin master	Pushes the changes in the local repository to the remote repository. Requests the password.
View remote repository configuration	git remote -v

Possible workflow for FESA FWK Developers

TODO

See issues above.

First implementation In Eclipse for FESA3

2020: https://git.acc.gsi.de/FESA3-Eclipse-Plug-In/eclipse-2020-06.git

2019: https://git.acc.gsi.de/FESA3-Eclipse-Plug-In/eclipse-2019-03.git

2018: https://git.gsi.de/s.matthies/fesa-eclipse-plugin-2018-12.git

Notes

• branches for features
• usage of issue IDs in commit messages
• partial commit of changes in single files possible
• changes in staged files for commits possible, not in local copy
• tags for releases instead of dedicated branch, different (branching) concept compared to SVN
• or immutable release branches?
• git merging / rebasing ?
• commit often locally, push best result to remote repository
• empty folder cannot be added, solution: create .gitkeep file

Links

• https://sethrobertson.github.io/GitBestPractices/
• https://raygun.com/blog/git-workflow/
• https://www.codeaffine.com/2014/09/22/access-git-repository-with-jgit/
• https://www.codeaffine.com/2015/05/06/jgit-initialize-repository/
• https://learngitbranching.js.org/
• https://git.acc.gsi.de/api/swagger
• https://git-scm.com/docs/git-init
• https://git-scm.com/book/en/v2/Git-Branching-Basic-Branching-and-Merging
• https://git-scm.com/book/en/v2/Git-Basics-Working-with-Remotes
• https://git-scm.com/book/en/v2/Git-Basics-Tagging
• http://stevelosh.com/blog/2013/04/git-koans/#the-hobgoblin
• https://wiki.eclipse.org/EGit/FAQ

-- SolveighMatthies - 08 Oct 2018