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diff --git a/doc/user/project/import/svn.md b/doc/user/project/import/svn.md new file mode 100644 index 00000000000..7a3628a39d7 --- /dev/null +++ b/doc/user/project/import/svn.md @@ -0,0 +1,183 @@ +# Migrating from SVN to GitLab + +Subversion (SVN) is a central version control system (VCS) while +Git is a distributed version control system. There are some major differences +between the two, for more information consult your favorite search engine. + +## Overview + +There are two approaches to SVN to Git migration: + +1. [Git/SVN Mirror](#smooth-migration-with-a-gitsvn-mirror-using-subgit) which: + - Makes the GitLab repository to mirror the SVN project. + - Git and SVN repositories are kept in sync; you can use either one. + - Smoothens the migration process and allows to manage migration risks. + +1. [Cut over migration](#cut-over-migration-with-svn2git) which: + - Translates and imports the existing data and history from SVN to Git. + - Is a fire and forget approach, good for smaller teams. + +## Smooth migration with a Git/SVN mirror using SubGit + +[SubGit](https://subgit.com) is a tool for a smooth, stress-free SVN to Git +migration. It creates a writable Git mirror of a local or remote Subversion +repository and that way you can use both Subversion and Git as long as you like. +It requires access to your GitLab server as it talks with the Git repositories +directly in a filesystem level. + +### SubGit prerequisites + +1. Install Oracle JRE 1.8 or newer. On Debian-based Linux distributions you can + follow [this article](http://www.webupd8.org/2012/09/install-oracle-java-8-in-ubuntu-via-ppa.html). +1. Download SubGit from https://subgit.com/download/. +1. Unpack the downloaded SubGit zip archive to the `/opt` directory. The `subgit` + command will be available at `/opt/subgit-VERSION/bin/subgit`. + +### SubGit configuration + +The first step to mirror you SVN repository in GitLab is to create a new empty +project which will be used as a mirror. For Omnibus installations the path to +the repository will be located at +`/var/opt/gitlab/git-data/repositories/USER/REPO.git` by default. For +installations from source, the default repository directory will be +`/home/git/repositories/USER/REPO.git`. For convenience, assign this path to a +variable: + +``` +GIT_REPO_PATH=/var/opt/gitlab/git-data/repositories/USER/REPOS.git +``` + +SubGit will keep this repository in sync with a remote SVN project. For +convenience, assign your remote SVN project URL to a variable: + +``` +SVN_PROJECT_URL=http://svn.company.com/repos/project +``` + +Next you need to run SubGit to set up a Git/SVN mirror. Make sure the following +`subgit` command is ran on behalf of the same user that keeps ownership of +GitLab Git repositories (by default `git`): + +``` +subgit configure --layout auto $SVN_PROJECT_URL $GIT_REPO_PATH +``` + +Adjust authors and branches mappings, if necessary. Open with your favorite +text editor: + +``` +edit $GIT_REPO_PATH/subgit/authors.txt +edit $GIT_REPO_PATH/subgit/config +``` + +For more information regarding the SubGit configuration options, refer to +[SubGit's documentation](https://subgit.com/documentation.html) website. + +### Initial translation + +Now that SubGit has configured the Git/SVN repos, run `subgit` to perform the +initial translation of existing SVN revisions into the Git repository: + +``` +subgit install $GIT_REPO_PATH +``` + +After the initial translation is completed, the Git repository and the SVN +project will be kept in sync by `subgit` - new Git commits will be translated to +SVN revisions and new SVN revisions will be translated to Git commits. Mirror +works transparently and does not require any special commands. + +If you would prefer to perform one-time cut over migration with `subgit`, use +the `import` command instead of `install`: + +``` +subgit import $GIT_REPO_PATH +``` + +### SubGit licensing + +Running SubGit in a mirror mode requires a +[registration](https://subgit.com/pricing.html). Registration is free for open +source, academic and startup projects. + +We're currently working on deeper GitLab/SubGit integration. You may track our +progress at [this issue](https://gitlab.com/gitlab-org/gitlab-ee/issues/990). + +### SubGit support + +For any questions related to SVN to GitLab migration with SubGit, you can +contact the SubGit team directly at [support@subgit.com](mailto:support@subgit.com). + +## Cut over migration with svn2git + +If you are currently using an SVN repository, you can migrate the repository +to Git and GitLab. We recommend a hard cut over - run the migration command once +and then have all developers start using the new GitLab repository immediately. +Otherwise, it's hard to keep changing in sync in both directions. The conversion +process should be run on a local workstation. + +Install `svn2git`. On all systems you can install as a Ruby gem if you already +have Ruby and Git installed. + +```bash +sudo gem install svn2git +``` + +On Debian-based Linux distributions you can install the native packages: + +```bash +sudo apt-get install git-core git-svn ruby +``` + +Optionally, prepare an authors file so `svn2git` can map SVN authors to Git authors. +If you choose not to create the authors file then commits will not be attributed +to the correct GitLab user. Some users may not consider this a big issue while +others will want to ensure they complete this step. If you choose to map authors +you will be required to map every author that is present on changes in the SVN +repository. If you don't, the conversion will fail and you will have to update +the author file accordingly. The following command will search through the +repository and output a list of authors. + +```bash +svn log --quiet | grep -E "r[0-9]+ \| .+ \|" | cut -d'|' -f2 | sed 's/ //g' | sort | uniq +``` + +Use the output from the last command to construct the authors file. +Create a file called `authors.txt` and add one mapping per line. + +``` +janedoe = Jane Doe <janedoe@example.com> +johndoe = John Doe <johndoe@example.com> +``` + +If your SVN repository is in the standard format (trunk, branches, tags, +not nested) the conversion is simple. For a non-standard repository see +[svn2git documentation](https://github.com/nirvdrum/svn2git). The following +command will checkout the repository and do the conversion in the current +working directory. Be sure to create a new directory for each repository before +running the `svn2git` command. The conversion process will take some time. + +```bash +svn2git https://svn.example.com/path/to/repo --authors /path/to/authors.txt +``` + +If your SVN repository requires a username and password add the +`--username <username>` and `--password <password` flags to the above command. +`svn2git` also supports excluding certain file paths, branches, tags, etc. See +[svn2git documentation](https://github.com/nirvdrum/svn2git) or run +`svn2git --help` for full documentation on all of the available options. + +Create a new GitLab project, where you will eventually push your converted code. +Copy the SSH or HTTP(S) repository URL from the project page. Add the GitLab +repository as a Git remote and push all the changes. This will push all commits, +branches and tags. + +```bash +git remote add origin git@gitlab.com:<group>/<project>.git +git push --all origin +git push --tags origin +``` + +## Contribute to this guide +We welcome all contributions that would expand this guide with instructions on +how to migrate from SVN and other version control systems. |