HOWTO: See what happened in SVN between builds

I was recently asked how to determine what changed between two builds. Jenkins provides nice interlinks into JIRA (issues), Fisheye (source changes), SVN (sources), but let's say you want to kick things a little more old school and investigate the old way... or the builds you want to compare are no longer shown in Jenkins because they expired and their metadata was automatically purged.

If you can't just look at the changelog in Jenkins to see what revision of source was used for the build, you can check the SVN log to find revision numbers based on the timestamp of the build.

So, if your build was generated on 2011-10-18, you can see that the log shows the last commit before that build was this:

$ svn log http://svn.jboss.org/repos/jbosstools/branches/jbosstools-3.2.x/

...

r35735 | bfitzpat | 2011-10-17 15:35:23 -0400 (Mon, 17 Oct 2011) | 2 lines
Changed paths:
   A esb/plugins/.project
   M esb/plugins/org.jboss.tools.esb.project.core/src/org/jboss/tools/esb/core/runtime/ESBRuntimeResolver_410.java

JBDS-1889 - Now checking for juddi-client-3.1.2.jar as well as 3.1.0 and 3.1.1 when seeing if the runtime includes ESB 4.10

...

Want to see actual diffs between that build and the latest one?

$ svn diff http://svn.jboss.org/repos/jbosstools/branches/jbosstools-3.2.x/@35735 http://svn.jboss.org/repos/jbosstools/branches/jbosstools-3.2.x/

Or, if you want to collect just the section of log relevant to the change:

$ svn log -r35735:HEAD http://svn.jboss.org/repos/jbosstools/branches/jbosstools-3.2.x/

Of course if you have all the sources locally, you don't need to log or diff via a URL - you can simply use local file paths. And if like me you use git-svn instead of pure svn, you can use that to diff or log too.

If you want to easily determine when a branch was created and get the SVN revision number for that branch point, use this:

# from r28571, returns -r28571:HEAD
rev=$(svn log --stop-on-copy \
  http://svn.jboss.org/repos/jbosstools/branches/jbosstools-3.2.x \
  | egrep "r[0-9]+" | tail -1 | sed -e "s#\(r[0-9]\+\).\+#-\1:HEAD#")

If you'd like to view a specific svn revision in your browser, use !svn/bc/REVISION_NUMBER/ before the branch and path to file or folder:

http://svn.jboss.org/repos/jbosstools/!svn/bc/35735/branches/jbosstools-3.2.x/

HOWTO: Contributing to JBoss Tools using Git

If you'd like to use Git instead of SVN as your SCM tool of choice, here's how you can connect to the JBoss Tools SVN repo, pull down all the sources, work on them locally, then either commit changes back into the SVN repo (or submit a patch, if you're not already a committer).

The instructions below assume you have either Linux, Mac OSX, or Windows w/ cygwin. If you have none of those, YMMV.

Fetch sources from SVN

First, fetch sources from SVN using git-svn. If you don't want to check out all the components, use a subset of the components listed below. The complete list is here.

# create a directory into which to check out the JBoss Tools projects
mkdir ~/trunk; cd ~/trunk;

# fetch projects - this will take quite some time
# Committers, use http://svn.jboss.org/repos/jbosstools/trunk/
# Contributors, use http://anonsvn.jboss.org/repos/jbosstools/trunk/
for d in \
  archives as birt bpel bpmn build cdi common \
  deltacloud documentation download.jboss.org drools \
  esb examples flow freemarker gwt hibernatetools \
  jbpm jmx jsf jst maven modeshape portlet profiler \
  requirements runtime seam site smooks struts \
  tests tptp usage vpe ws xulrunner; do \
    git svn clone http://anonsvn.jboss.org/repos/jbosstools/trunk/${d};
done

Configure Eclipse

Next, fire up Eclipse Helios 3.6 for Java EE Developers.

Install the latest eGit from http://download.eclipse.org/egit/updates.

Install the latest m2eclipse from http://m2eclipse.sonatype.org/sites/m2e/ and optionally, http://m2eclipse.sonatype.org/sites/m2e-extras/.

Restart when prompted.

Import Git projects into Eclipse

Now, import Git projects into Eclipse using:

File > Import 
    Git > Projects from Git
        Click 'Add' then browse for ~/trunk/ 
        Enable [x] Look for nested repositories 
        Click 'Search', then click 'OK' when done

        Select a local repo from the list, click 'Next'
        (*) Import Existing Projects
        (*) Try to share automatically
        Click 'Next'
        Click 'Select All', then click 'Finish'

Repeat for other components you want to import. You can add each component to a working set to keep your workspace sorted by component.

Resolve missing dependencies

While the Eclipse Helios 3.6 for Java EE Developers contains most of the dependencies against which JBoss Tools must be compiled, it does not contain everything. For that, you need to install extra dependencies. There are two places to go:

1. JBoss Tools Target Platform p2 Repo (also available as an archived update site zip for offline use) - contains all the Eclipse.org, google.com, and sonatype.org features needed to compile / install all of JBoss Tools. You can install everything, or just the pieces you need.
2. JBoss Tools Nightly Repo (Update Site) - if you don't have all the source projects in your workspace, you can resolve dependencies against this site and install them from here. Once again, you can install everything, or just the pieces you need.

Build & run tests

With m2eclipse installed, you can simply right-click a project and select 'Run As > Maven Build (ALT-SHIFT-X, M)', which will prompt you complete a run configuration dialog. Here are the simplest options you need to set:

   Goals: clean install
   [x] Resolve Workspace artifacts

You can also run Maven to build your projects outside Eclipse, if you prefer.

If running outside Eclipse, you can run tests which are still tied to the Eclipse debugger.

Commit changes to master repo

Because there's no support yet for 'git svn rebase' or 'git svn dcommmit' you're stuck pushing changes to the master repo using the commandline. However, you can shorten the amount of typing needed using an .alias file. See below.

Use an .alias file

To avoid having to type the same git commands over and over, I use these shortcuts in my ~/.alias file:

# update local git-svn repo from master SVN repo
alias   gitup='for d in $(find . -maxdepth 1 -type d); do cd $d; echo $d; if [[ -d .git ]]; then git svn rebase; fi; cd -; done'

# Push local changes to master SVN repo
alias   gp='git svn rebase; git svn dcommit'

# commit local changes to local git-svn repo
alias   ci='git commit -m'

# check status of local git-svn repo
alias   stat='git status'

So, after committing changes (with eGit or via commandline) I can push those to the master SVN repo w/ a simple 'gp'. If your shell doesn't read the .alias file, make sure your .bashrc loads the file using one of these commands:

source /home/yourUserName/.alias
. /home/yourUserName/.alias

Or, put them directly in your .bashrc file.