= Migrating GRASS code repository from SVN to git =

== Background and aims ==

SVN has served the GRASS project well as a version control system for 
numberous years now. The project has estabished routines and infrastructure 
(code repository, ticketing system, developer wiki) connected to SVN. 
However, with an increasing number of Open Source developers using git 
(and here especially the success of github), interest in moving from SVN 
to git has been expressed. 

Reasons to consider moving from SVN to git are to:
* increase the number of contributers and thus contributions due of the popularity of git
* make features and functionality of git available for developing GRASS and thus
* make the current GRASS developers happy that prefer git (even if git can already be used against SVN: https://trac.osgeo.org/grass/wiki/HowToMaintainGrassWorkflowUsingGit)

Other OSGeo projects already moved (even if some only partly)
* GDAL moved to github (https://trac.osgeo.org/gdal/wiki/rfc71_github_migration)
* QGIS has been on github for a while already ()
* GEOS seems to be on gitea (provided by OSGeo)
* ...

See e.g.:
https://git.osgeo.org/gitea/strk/trac2gogs

Like other OSGeo projects GRASS has already a git-mirror-repository for CI:
* https://github.com/GRASS-GIS  (used for Travis CI, in sync)
In addition GRASS has a team within the OSGeo organisation on github.com:
* https://github.com/orgs/OSGeo/teams/grass-gis

Possible migration of GRASS code to git has been discussed at community 
sprints in 2017 and 2018. At the community Sprint in Bonn 2018 first tools 
for moving content from trac (SVN) to git were developed (mainly by Martin Landa):
https://trac.osgeo.org/grass/browser/grass-addons/tools/svn2git?order=name


== Choosing a git plattform ==

Moving to git involves the question which git platform to move to. So, in 
addition to technical work, strategical decisions have to be made.

=== Available options ===

Most common options / git platforms are:
* github (still the most popular, yet proprietary, system with online hosting service)
* gitlab (another plattform with online hosting service and increasing popularity esp. after Microsoft bought github)
* bitbucket (another popular plattform with online hosting service)
* gitea/gogs ("painlessly selfhosted" plattform, hosted by OSGeo SAC)

Yet, there are plenty of other options:
https://wiki.osgeo.org/wiki/GitHostingSoftware

And there are several comparisons of available git platforms available online:
https://wiki.osgeo.org/wiki/GitInfrastructureComparison
https://ethercalc.org/choose-the-git-host.html

=== Requirements and criteria ===

Anyway, a first step in order to chose from the available options is to define a 
list of criteria (here requirements and features) of the git platform to 
move to. For OSGeo a list of requirements has been compiled:
https://wiki.osgeo.org/wiki/GitServiceRequirement
Yet, that list does not necessarily reflect all or the most important 
requirements of the GRASS project and the motivation for moving to git...


* Sign in using OSGeo Userid
* Autonomously create and manage teams
* Autonomously create and manage repositories
* Create private repositories (for software vulnerability testing, etc.)
* Import tickets from Trac
* Import tickets from Redmine
* Comment tickets via email
* Comment/close tickets via commit log
* SVN->GIT sync - (Mirroring existing SVN repository) see:/ticket/1654
* Integration with CI service (hosted eg. Travis CI, AppVeyor, GitLab CI), self-hosted (eg. Buildbot, ?))
* ... (Please add)


== Next steps ==

Prepare a PSC decision e.g. with a user/developer survey?