Update on Version Control Systems: GitLab, SVN, Git, Trac, CERNforge Alexandre Lossent IT-PES-IS 5th LHCb Computing Workshop, 22 May 2015

Version Control Systems in use at CERN Central SVN service Access control, CERN accounts, e-groups Central Git service git.cern.ch and now GitLab (gitlab.cern.ch) Github Nowadays de-facto standard for Open Source projects with external partners Some projects mirror their repos at CERN Other private installations Git, SVN, Stash etc. Smaller groups with specific needs (and system resources) Should not be visible on the Internet 5th LHCb Computing Workshop, 22 May 2015

Improving Central VCS offering at CERN Looking for solutions to typical challenges How to ensure the quality of new features/fixes? How to decide if the code is ready for production? How to manage concurrent work and merge conflict resolution? How to be confident that code working on a dev’s machine will work as expected after deployment? How to enable contributions from outside the core dev team without risking damage to the code repository? Making it easier to create and manage code repositories And streamline integration with related services: Issue Tracking, Continuous Integration, Documentation… 5th LHCb Computing Workshop, 22 May 2015

5th LHCb Computing Workshop, 22 May 2015 Why deploy GitLab? Complement Version Control Services with new features to help developers implement software development best practices Provide a mean to review code and test results, discuss and take decision whether to merge code Associate code changes with a ticket in an Issue Tracking system– Provide code review features to help improve code quality Encourage collaboration by enabling project forks and merge requests Make it easier to run tests with Continuous Integration platforms Well-defined roles within a project or group of projects 5th LHCb Computing Workshop, 22 May 2015

5th LHCb Computing Workshop, 22 May 2015 GitLab project page 5th LHCb Computing Workshop, 22 May 2015

GitLab repository browsing 5th LHCb Computing Workshop, 22 May 2015

5th LHCb Computing Workshop, 22 May 2015 GitLab graphs 5th LHCb Computing Workshop, 22 May 2015

GitLab code review: Merge Request 5th LHCb Computing Workshop, 22 May 2015

GitLab feature summary On-premise “GitHub lookalike” Version Control based on Git With SSH support & SSH key authentication Hierarchical project (= repository) organization Groups – contain multiple projects for a given team Personal workspace – removed when user leaves CERN, a la home directory Code browsing Including editing files from the web interface Code review workflow Important branches are protected Changes submitted from feature branches or project forks Merge Requests reviewed by “master” developers before being merged Self-service One-click project creation, repository immediately available to work with Integration Global CERN services: SSO, SSH keys, mapping of E-groups to roles… Developer services: Jira, Jenkins (a Continuous Integration platform)… 5th LHCb Computing Workshop, 22 May 2015

5th LHCb Computing Workshop, 22 May 2015 Git, GitLab and Github GitLab is now in production and recommended Provides additional features compared to git.cern.ch (Gitolite-based) collaboration and code review features Recommended for all new version control projects hosted at CERN To get started: KB0003137 Librarians can move repositories from git.cern.ch to GitLab: KB0003111 Git.cern.ch is no longer recommended for new projects Self-service requests for new projects will be moderated from 1 Jul 2015 Longer term future of git.cern.ch will be evaluated at a later stage Github.com may be appropriate For open source and projects with external collaborators GitLab at CERN supports CERN accounts only Advice on choosing between CERN GitLab and GitHub.com: KB0003132 5th LHCb Computing Workshop, 22 May 2015

5th LHCb Computing Workshop, 22 May 2015 SVN Service SVN will continue for established projects Maintenance updates but no additional development is planned New projects are encouraged to use GitLab New SVN repository requests will be moderated from 1 Jul 2015 Migration from SVN to GitLab will be possible Librarians will be contacted in due time to discuss potential migrations The Trac add-on to SVN will be maintained for code browsing in projects already using it JIRA, web services (e.g. Twiki) are recommended for tickets, wiki, etc The recommended SVN web interface is websvn Jira migration instructions will be provided for those who wish to do so Issues raised in the May Trac survey are being followed up with users 5th LHCb Computing Workshop, 22 May 2015

5th LHCb Computing Workshop, 22 May 2015 JIRA Service JIRA currently hosts ~540 projects Upgrade from JIRA 6.3.13 to 6.4.x is planned During summer or early autumn Fisheye/Crucible server will be stopped at end of 2015 Has problems with scalability Less user friendly than GitLab for code review Recommended replacement is GitLab Affects relatively few users 5th LHCb Computing Workshop, 22 May 2015

5th LHCb Computing Workshop, 22 May 2015 CERNforge CERNforge http://cernforge.cern.ch Portal for creating and managing resources related to code management Has been updated to reflect changes to the Git, GitLab, SVN and JIRA services outlined on the previous slides 5th LHCb Computing Workshop, 22 May 2015

Software Development Workflow* Issues/requests Jenkins job Users GITLAB Commit changes Developers Software Release Internal Software Build SVN GIT Test Results Release Build Automatic tests Review & Merge *This is a simplified example of a possible workflow with the supported tools [Thanks to Manuel Gonzalez Berges (EN-ICE) for this slide] 5th LHCb Computing Workshop, 22 May 2015

5th LHCb Computing Workshop, 22 May 2015 GitLab: good to know The code review workflow replaces fine-grained permissions: KB0003135 GitLab has just a few predefined roles: Guest, Developer, Master, Owner Branches have a ‘protected’ flag (on for master by default) to: Prevent force push and branch deletion Force developers to use feature branches and the code review workflow SSH access via nonstandard port 7999: KB0003136 Available from outside CERN. Copy URL from project page! The Public visibility level really is public: KB0003122 Worldwide anonymous access, incl. search engines no “CERN Public” visibility level! Use SSH Deploy Keys for automated pull operations (build, deploy jobs etc.): KB0003129 Don’t forget to add [gitlab.cern.ch]:7999 to known_hosts E-groups can be used at the Group level, but not for individual projects I.e. all projects in a group are more or less expected to share same permissions. Workarounds possible. A future KB article will cover this. 5th LHCb Computing Workshop, 22 May 2015

Summary of GitLab resources Getting started: KB0003137 Set up SSH keys: KB0003136 Permissions in GitLab: KB0003122 Moving repositories from git.cern.ch to GitLab: KB0003111 Other KB articles: see GitLab topic in the Service Portal GitLab help: https://gitlab.cern.ch/help Feedback & support: Git Service in the Service Portal 5th LHCb Computing Workshop, 22 May 2015

5th LHCb Computing Workshop, 22 May 2015 Questions? 5th LHCb Computing Workshop, 22 May 2015