R – how to configure svn Task in CruiseControl.net to detect subversion external changes

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