Jenkins – How to build a specific revision of SVN in Hudson/Jenkins

CruiseControl.Net 1.4.4 has now an Assembly Version Labeller, which generates version numbers compatible with .Net assembly properties.

In my project I have it configured as:

<labeller type="assemblyVersionLabeller" incrementOnFailure="true" major="1" minor="2"/>

(Caveat: assemblyVersionLabeller won't start generating svn revision based labels until an actual commit-triggered build occurs.)

and then consume this from my MSBuild projects with MSBuildCommunityTasks.AssemblyInfo :

<Import Project="$(MSBuildExtensionsPath)\MSBuildCommunityTasks\MSBuild.Community.Tasks.Targets"/>
<Target Name="BeforeBuild">
  <AssemblyInfo Condition="'$(CCNetLabel)' != ''" CodeLanguage="CS" OutputFile="Properties\AssemblyInfo.cs" 
  AssemblyTitle="MyTitle" AssemblyCompany="MyCompany" AssemblyProduct="MyProduct"
  AssemblyCopyright="Copyright ©  2009" ComVisible="false" Guid="some-random-guid"
  AssemblyVersion="$(CCNetLabel)" AssemblyFileVersion="$(CCNetLabel)"/>
</Target>

For sake of completness, it's just as easy for projects using NAnt instead of MSBuild:

<target name="setversion" description="Sets the version number to CruiseControl.Net label.">
    <script language="C#">
        <references>
            <include name="System.dll" />
        </references>
        <imports>
            <import namespace="System.Text.RegularExpressions" />
        </imports>
        <code><![CDATA[
             [TaskName("setversion-task")]
             public class SetVersionTask : Task
             {
              protected override void ExecuteTask()
              {
               StreamReader reader = new StreamReader(Project.Properties["filename"]);
               string contents = reader.ReadToEnd();
               reader.Close();
               string replacement = "[assembly: AssemblyVersion(\"" + Project.Properties["CCNetLabel"] + "\")]";
               string newText = Regex.Replace(contents, @"\[assembly: AssemblyVersion\("".*""\)\]", replacement);
               StreamWriter writer = new StreamWriter(Project.Properties["filename"], false);
               writer.Write(newText);
               writer.Close();
              }
             }
             ]]>
        </code>
    </script>
    <foreach item="File" property="filename">
        <in>
            <items basedir="..">
                <include name="**\AssemblyInfo.cs"></include>
            </items>
        </in>
        <do>
            <setversion-task />
        </do>
    </foreach>
</target>

Create a users file (i.e. users.txt) for mapping SVN users to Git:

user1 = First Last Name <email@address.com>
user2 = First Last Name <email@address.com>
...

You can use this one-liner to build a template from your existing SVN repository:

svn log -q | awk -F '|' '/^r/ {gsub(/ /, "", $2); sub(" $", "", $2); print $2" = "$2" <"$2">"}' | sort -u > users.txt

SVN will stop if it finds a missing SVN user, not in the file. But after that, you can update the file and pick up where you left off.

Now pull the SVN data from the repository:

git svn clone --stdlayout --no-metadata --authors-file=users.txt svn://hostname/path dest_dir-tmp

This command will create a new Git repository in dest_dir-tmp and start pulling the SVN repository. Note that the "--stdlayout" flag implies you have the common "trunk/, branches/, tags/" SVN layout. If your layout differs, become familiar with --tags, --branches, --trunk options (in general git svn help).

All common protocols are allowed: svn://, http://, https://. The URL should target the base repository, something like http://svn.mycompany.com/myrepo/repository. The URL string must not include /trunk, /tag or /branches.

Note that after executing this command it very often looks like the operation is "hanging/frozen", and it's quite normal that it can be stuck for a long time after initializing the new repository. Eventually, you will then see log messages which indicate that it's migrating.

Also note that if you omit the --no-metadata flag, Git will append information about the corresponding SVN revision to the commit message (i.e. git-svn-id: svn://svn.mycompany.com/myrepo/<branchname/trunk>@<RevisionNumber> <Repository UUID>)

If a user name is not found, update your users.txt file then:

cd dest_dir-tmp
git svn fetch

You might have to repeat that last command several times, if you have a large project until all of the Subversion commits have been fetched:

git svn fetch

When completed, Git will checkout the SVN trunk into a new branch. Any other branches are set up as remotes. You can view the other SVN branches with:

git branch -r

If you want to keep other remote branches in your repository, you want to create a local branch for each one manually. (Skip trunk/master.) If you don't do this, the branches won't get cloned in the final step.

git checkout -b local_branch remote_branch
# It's OK if local_branch and remote_branch are the same names

Tags are imported as branches. You have to create a local branch, make a tag and delete the branch to have them as tags in Git. To do it with tag "v1":

git checkout -b tag_v1 remotes/tags/v1
git checkout master
git tag v1 tag_v1
git branch -D tag_v1

Clone your GIT-SVN repository into a clean Git repository:

git clone dest_dir-tmp dest_dir
rm -rf dest_dir-tmp
cd dest_dir

The local branches that you created earlier from remote branches will only have been copied as remote branches into the newly cloned repository. (Skip trunk/master.) For each branch you want to keep:

git checkout -b local_branch origin/remote_branch

Finally, remove the remote from your clean Git repository that points to the now-deleted temporary repository:

git remote rm origin