Tuesday, August 25, 2009

Hudson, iPhone, Xcode and Unit Testing

After much messing about I have finally managed to get Hudson to work with xcodebuild, this is for an Objective C iPhone project, so the things below were modified to fit our requirements

I have the following things running
  • Automated Builds (SCM polled every 15 minutes for changes)
  • Unit Testing (courtesy of google toolbox for mac)
  • Profiling (a modified version of the gcovr python script + some nice compiler flags)
  • Code Coverage (courtesy of Cobertura, gcovr, profiling and scan-build)
  • Static analysis reports (CLang)

This is what I have:

  • mac mini (continuous integration server)
  • Snow Leopard Server (10A433)
  • Apache Tomcat (Application Server)
  • Hudson (Continuous integration)
  • Hudson Cobertura Plugin
  • Subversion (SCM)
  • gcovr (slightly modified to fit)
  • A whole bunch of Apple documentation (and some dead trees)
onward ... to the setup!!

Having used Hudson quite a bit in the past as a CI environment, I was careful to ensure that my HUDSON_HOME was located in a separate location from the tomcat installation, This makes installing updates to hudson relatively easy (just dump the new war file into the WEBAPPS directory and restart Tomcat).

I segregated the user which runs the tomcat environment (not the standard _appserver user), its just a habit I have and it lets me be able to pick out my processes a lot easier. On an OSX Server you'll want to add a new group and user (_tomcat for the group and _tomcat for the user), try and stay below 500 for the userid, that way you its not a real user (to the operating system).

Getting your Tomcat environment to Auto start on boot and restart if it dies require the use of a plist file (we'll look at that later) and launchctl to load it. The plist also needs to be copied to /System/Library/LaunchDaemons so that it will restart on boot.

Here is what you will need to acquire before beginning:
  1. The hudson war file
  2. A copy of gcovr (you will need to do some modfication to make this work if you have no unit tests)
  3. An iPhone project
  4. Some actual Unit tests defined as a build setting (I used UnitTests -please tell me you wrote tests for your code?)
  5. xcode installed
  6. iPhone SDK installed
  7. Your Mac
  8. Patience
  9. Time
Here we go ...
Here is my handy dandy script to go add the user/group, fix up some permissions, create some directories and fire up Tomcat with Hudson installed, just make sure you have you hudson.war file in the directory you run this script from, you'll also either need to be root (sudo su -) or sudo to run it (sudo ./configure_tomcat.sh).

#!/usr/bin/env bash

if [ ! -f ./hudson.war ];
echo "You are missing the hudson war file in this directory"
exit 1
elif [ ! -f ./server.xml ];
echo "You are missing the server.xml file in this directory"
exit 1

elif [ ! -f ./org.apache.tomcat.plist ];
echo "You are missing the org.apache.tomcat.plist file in this directory"
exit 1

echo "+ Ready to install .."

# Is tomcat already running? If so - unload it, reconfigure then reload

TCRUN=`launchctl list org.apache.tomcat 2> /dev/null | wc -l`

if [ $TCRUN != 0 ];
# Tomcat is running already - unload it
echo "+ Tomcat appears to be running, unloading ready for configuration"
launchctl unload org.apache.tomcat.plist
# Tomcat isn't running
echo "+ Tomcat not running, ready to configure"

# Determine if our users and groups already exist, if so - don't recreate them, else, go and make them

ISTOMCATGRP=`dscl . -list /Groups | grep _tomcat`
ISTOMCATUSR=`dscl . -list /Users | grep _tomcat`

if [ ! -d /usr/local/ ];
mkdir /usr/local

if [ "$ISTOMCATGRP" == "" ];
# create the tomcat user for hudson to run as ...
echo ""
echo "+ Creating group _tomcat as PrimaryGroupID 300"
echo ""
dscl . -create /Groups/_tomcat PrimaryGroupID 300
dscl . -create /Groups/_tomcat RealName "Tomcat Users"
dscl . -create /Groups/_tomcat Password \*
sleep 5

if [ "$ISTOMCATUSR" == "" ];
# Create the _tomcat user in the _tomcat group
echo ""
echo "+ Creating the _tomcat user as UniqueID 300, PrimaryGroupID 300, NFSHomeDirectory /usr/local/tomcat"
echo ""
mkdir /usr/local/tomcat
chgrp _tomcat /usr/local/tomcat
chmod g+w /usr/local/tomcat
dscl . -create /Users/_tomcat UniqueID 300
dscl . -create /Users/_tomcat PrimaryGroupID 300
dscl . -create /Users/_tomcat NFSHomeDirectory /usr/local/tomcat
dscl . -create /Users/_tomcat UserShell /bin/sh
dscl . -create /Users/_tomcat RealName "Tomcat Administrator"
dscl . -create /Users/_tomcat Password \*
sleep 5

# chgrp the entire /Library/Tomcat directory to _tomcat

chgrp -R _tomcat /Library/Tomcat

echo ""
echo "+ Copying server.xml and hudson.war to required locations"
echo ""

cp server.xml /Library/Tomcat/conf
cp hudson.war /Library/Tomcat/webapps

sleep 5

echo ""
echo "+ Installing the org.apache.tomcat service via launchctl"
echo ""

chown root ./org.apache.tomcat.plist
launchctl load ./org.apache.tomcat.plist
cp ./org.apache.tomcat.plist /System/Library/LaunchDaemons

echo "Install complete - Hudson is available here http://`hostname`:8080/hudson"
echo ""
Get a copy of the server.xml file from the /Library/Tomcat/conf directory, find the server.xml file and copy it to the same directory as the above script.

Modify the server.xml to have the following in the connector section


Finally, get a copy of the org.apache.tomcat.plist file from /System/Library/LaunchDaemons and modify it as follows:

  • Add HUDSON_HOME as a key in the Environment Variables section
  • Set the string for HUDSON_HOME to be /usr/local/hudson
  • Change the UserName to be _tomcat
  • Modify the Disabled key to be Enabled

Now that we have the above (saved to your machine) we should be ready to proceed

run the script (the first listing) - this will add groups, users etc, and setup your application environment and launch hudson.

That was easy :)

Next step - configuring your hudson environment to compile your code (ala xcodebuild)

Jump into Hudson (http://localhost:8080/hudson) and do the following
  • Click on "Manage Hudson" -> "Manage Plugins" -> "Available"
  • Add the following plugins
  1. Hudson Cobertura plugin
  2. Hudson Disk Usage plugin
  3. Hudson DocLinks plugin
Once the plugins are downloaded hit the restart button in hudson

Now that we have these plugins available, we need to get a copy of scan-build (static analysis reporting) and gcovr (python based code coverage output in cobertura style XML format)

I extracted the scan-build checker package and installed it into /usr/bin (scan-build and scan-view) all of the libs into /usr/lib, the libexecs to /usr/libexec and the man pages into /usr/share

If you have no unit tests, you may need to modify gcovr to work, just edit line 178 and change the extension from gcda to gcno.

Now that we have all of the bits and pieces installed, its time to configure a job:

Go back to the main hudson page, click on "Manage Job"

Add a new job with the following options:

  • Build a free-style software project
  • Give your project a name and click on OK
  • Select your SCM (I use Subversion)
  • Enter the details for your repository location
  • Set your build triggers (I poll the scm every 15 minutes for changes */15 * * * *)
  • Make the build paramaterized (I set it as a "Choice" with the name TARGET and the options UnitTest and the Project Name as the second choice)
  • Add a build step (Execute shell) with the following

  • cd Whatever your project is called in the repository && scan-build xcodebuild clean -target "${TARGET}" -configuration Debug -sdk iphonesimulator3.0 GCC_GENERATE_TEST_COVERAGE_FILES=YES PREBINDING=NO GCC_OPTIMIZATION_LEVEL=0 && rm -rf html
  • Add another Build step (execute shell) with the following

  • cd Whatever your project is called in the repository && scan-build -o html xcodebuild -target "${TARGET}" -configuration Debug -sdk iphonesimulator3.0 GCC_GENERATE_TEST_COVERAGE_FILES=YES PREBINDING=YES GCC_OPTIMIZATION_LEVEL=0 DEAD_CODE_STRIPPING=YES GCC_DEBUGGING_SYMBOLS=full GENERATE_PROFILING_CODE=YES GCC_INSTRUMENT_PROGRAM_FLOW_ARCS=YES OTHER_LDFLAGS=" -L//Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator3.0.sdk/usr/lib/gcc/i686-apple-darwin10/4.2.1/ -fprofile-arcs -lgcov -prebind "
  • Add one last build step (execute shell) with the following

  • cd Whatever your project is called in the repository && /usr/bin/gcovr -r . -x -b -e /Developer 1> html/coverage.xml 2>/dev/null
A brief explanation about what happens above
  1. Cleans out your build directory
  2. scan-build the code (CLang static analysis) and add profiling and test coverage
  3. Profiling will occur once the unit tests begin and generate gcda files analyzing the code you actually invoke (cobertura style too)
  4. Finally we generate the cobertura information using gcovr
Now - we need to add the static analysis output
  • Click on publish documents
  • Give it a title and description (static analysis is a good choice)
  • Set the directory to be Whatever your project is called in the repository/html
Now add the cobertura coverage
  • Click on publish cobertura coverage report
  • Set the xml report pattern to **/html/coverage.xml
  • Modify the coverage settings to suit
  • Click on consider only stable builds
That should be it?!?

Now save the project and start it up - you should now get some funky code coverage, and static analysis. If it all goes belly up, click on the build and look at the console ouptut, this should point you in the right direction.

You should really be using google toolbox for mac (with the iPhone Unit testing enabled) this allows for some really good profiling of your application.