Archive for June, 2011

Mercurial Server using hgweb.cgi on Ubuntu

June 30, 2011 Leave a comment

In a previous post, we set up a virtual machine template for an ubuntu server. Now that we have set up a clone of this machine, it is time to set up a Mercurial repository server


Mercurial provides an easy to use repository server via a python cgi script. Mercurials protocol facilitates fast transfers over http, making it superior over an ssh solution based (such as git) when considering minimal protocol overhead vs. ease of use. As my webserver of choice, we will use lighttpd. This guide will follow the instructions published here

Installing Python

This one is simple:

ubuntu@localhost: sudo apt-get install python

Installing Lighttpd

To install lighttpd, run:

ubuntu@localhost: sudo apt-get install lighttpd

Next, we need to create a specific configuration for our mercurial cgi script. We need to redirect all incoming requests to the cgi script, and then we apply some url rewrite magic to remove the ugly hgweb.cgi from our URLs. The hgweb.cgi script will be served from /var/www/hgweb.cgi. If you use a different location, make sure to chown it to www-data and chmod+x it (all described in the mercurial wiki). I created my config like this:

ubuntu@localhost:~$ sudo vi /etc/lighttpd/hg.conf
ubuntu@localhost:~$ cat /etc/lighttpd/hg.conf 
url.rewrite-once = (
  "^([/?].*)?$" => "/hgweb.cgi$1",
   "^/([/?].*)?$" => "/hgweb.cgi$1"

$HTTP["url"] =~ "^/hgweb.cgi([/?].*)?$" {
             server.document-root = "/var/www/"
             cgi.assign = ( ".cgi" => "/usr/bin/python" )

Next is the lighttpd config, that will need to reference our hg.conf and enable mod_cgi:

ubuntu@localhost:~$ cat /etc/lighttpd/lighttpd.conf 
include "hg.conf"

server.modules = (

Further configuration Tricks

You should force hgweb.cgi to serve UTF-8 content. Fortunately enough, this is as simple as adding (or uncommenting) the following lines to hgweb.cgi:

import os
os.environ["HGENCODING"] = "UTF-8"

You will also need a hgweb.conf right next to hgweb.cgi and reference it from there (again, described in the mercurial wiki). For reference, my configuration includes all repos sourced under /var/hg/repos (and subdirectories) and allows anonymous push (I’m authenticated via VPN policy):

ubuntu@localhost:~$ cat /var/www/hgweb.config
/ = /var/hg/repos/**

baseurl = /
allow_push = *
push_ssl = false

Final Words

That’s all there is to it. To make the server available via DNS, you need to make sure the servers hostname is registered with your local DNS. In my case, I simply added a static record to it.

Objective-C Pitfall: Synthesized Properties without backing field

June 29, 2011 2 comments

This is just a quick and short post about an Objective-C pitfall I have encountered today. When using synthesized properties, you do normally supply a backing field:

@property (nonatomic, readwrite, retain) Message* message = message_;

This will synthesize a getter and setter, that will use message_ as its backing field. Since I found out one can go clever and ommit the backing field, so a simple line like this will work too:

@property (nonatomic, readwrite, retain) Message* message;

However, now we get into a bit of trouble when accessing the property. Contrary to the behavior in Java or C#, you now get something different when accessing 




. While the former will use the synthesized getter, the latter will use the synthesized backing field directly. This is a bit unexpected (I thought the backing field would be anonymous). So, my general advice would be to always use backing fields in your synthesized backing fields, so you don’t accidentally forget a “self.”. (This is water on the mills of people that advocate _not_ using the dot syntax for properties).



Categories: iPhone, Objective-C

TeamCity Server on Ubuntu

June 18, 2011 7 comments

Last time, we set up a virtual machine template for an ubuntu server. Now that we have set up a clone of this machine, it is time to set up Teamcity on it.


Teamcity on linux is meant to be run from its integrated Tomcat server. We will use the default Teamcity installation procedure in combination with the lightweight lighttpd to act as a front end server listening on port 80 and forwarding requests to Teamcity’s Tomcat installation. This setup is both, easier than configuring Tomcat on Port 80 (remember it requires root permissions to allocate) and we could add authentication or https access more easily later (though I will not do that for now).

Installing Teamcity

To install Teamcity, follow the instructions from JetBrains, which can be found here (takes less than 10 minutes). I chose to install mine at /var/TeamCity: 

Follow the instructions to set up your external database (recommended approach). I am using a SQL Server 2008 Installation that is already present and regularly backed up in my “private cloud”.  Edit your server.conf to configure a port for the Tomcat Server :

ubuntu@localhost: sudo vi /var/TeamCity/conf/server.xml

Permissions are a chore, but we don’t want the Teamcity Server directory to be owned by our admin user, so we change the owner of our Teamcity install directory to the default www-data user.

ubuntu@localhost: sudo chown -R www-data /var/TeamCity

Next, we want Teamcity to start automatically when the server is booted, so we add a small init script. Be sure to adjust the TEAMCITY_DATA_PATH environment variable to a static directory of your choice, otherwise TCs default will make end up in www-data’s home directory, which is, frankly, a very inconvenient location.

ubuntu@localhost:/var/TeamCity$ cat /etc/init.d/teamcity 
# /etc/init.d/teamcity -  startup script for teamcity
export TEAMCITY_DATA_PATH="/var/TeamCity/.BuildServer"

case $1 in
 start-stop-daemon --start  -c www-data --exec /var/TeamCity/bin/ start

 start-stop-daemon --start -c www-data  --exec  /var/TeamCity/bin/ stop


exit 0

Now we need to register the startup script to run automatically:

ubuntu@localhost: sudo update-rc.d teamcity defaults

Next, we start the server manually (you can reboot too):

ubuntu@localhost: sudo /etc/init.d/teamcity start

Installing Lighttpd

Now we need to install lighttpd:

ubuntu@localhost: sudo apt-get install lighttpd

And configure it to forward requests from port 80 to the port we configured for Tomcat (8080 in my case).

ubuntu@localhost: sudo vi /etc/lighttpd/lighttpd.conf
server.modules = (
#       "mod_rewrite",

$HTTP["host"] =~ "" {
        proxy.server = (
                "" => (
                        "tomcat" => (
                                "host" => "",
                                "port" => 8080,
                                "fix-redirects" => 1

Final Words

That’s it. By now you should have a running teamcity server. If something goes wrong, be sure to check the logs which can be found at /var/TeamCity/logs. To make the server available via DNS, you need to make sure the servers hostname is registered with your local DNS. In my case, I simply added a static record to it.

Ubuntu Server on HyperV

June 17, 2011 Leave a comment

As my Linux distro of choice for a set of lightweight virtualized Servers, Ubuntu Sever provides several advantages that made me go for it:

* Driver support for HyperV
* Active Community, number of HowTo’s available considered superior to Debian
* Packages available are cutting edge
* Well documented
* Good experience with Ubuntu Desktop

At the time of writing this, there are two choices of Ubuntu Server: Ubuntu 10 with LTS or cutting edge Ubuntu 11. LTS stands for LongTermSupport and Cannonical guarantees there will be updates for at least 3 years. It’s a matter of preference, but I chose Ubuntu 11.

To install it in HyperV, I recommend you follow this guide:

Of course, you should adapt your network configuration to your requirements. Before templating this machine, I installed openssh because I consider it a core part of my server administration toolkit.

By this point, we should have a core installation of Ubuntu Server template that is ready to be cloned. Depending on your virtualization solution of choice, different steps apply here. (In HyperV it is as simple as exporting and re-importing the machine.) Make sure you create a unique copy of the machine, so that its network adapter gets assigned a new MAC Adress (everything else is calling for trouble).

After instantiating your template, we now need to customize that template:

1. Change hostname
 sudo hostname "NewHostName"

2. Configure Networking (it is likely your adapter will now show up as eth1 instead of eth0, rember that instantiating a VM tempate involves changing the MAC adress of the server)

sudo vi /etc/network/interfaces

3. Change user name/password

sudo passwd

4. Reboot

sudo shutdown -r now

GoodReader and Mercurial for the Ultimate Student Workflow

June 8, 2011 Leave a comment

Being the proud owner of a shiny new iPad2 for the last month or so, I found it to be a valuable companion at University. No, not for browsing stackoverflow, keeping up with RSS and E-Mail, but for managing lecture slide decks, assignments etc.

In the past semester, I started managing my documents in a mercurial repository that is synced against my private mercurial server installation. This made it easier for me to keep my multiple devices synchronized (who would need that iCloud thing…). My first attempts at using the iPad for these tasks was using iBooks. iBooks is not bad, but its so utterly limited that it sucks really hard from times to times. Especially annoying is that it has absolutely no file management capabilities whatsoever.

I found GoodReader to be a great alternative. It has excellent file management and supports annotating pdfs. But the best thing is its support for synchronizing your files:

  1. Make sure your iPad is connected to the same network as your host computer
  2. Launch GoodReader, open the WiFi sync mode via the WiFi symbol
  3. Mount http://yourIpad’sIpAdress:8080 has a network folder
  4. Open a terminal, cd into your mount point  and run hg clone /yourCentralRepository
  5. The next time you want to sync run hg pull -U
It takes less than 5 minutes to set up, and is a pretty damn smart workflow!
Categories: iPhone, Tools

iOS Development Continous Integration Setup

June 7, 2011 Leave a comment

After almost a year of absence, I’m in the middle of getting back to iOS Development. Since my departure from the Apple ranch, a lot has changed and new developer tools have emerged. Professional software development has become significantly easier on this platform, but I feel the tooling still isn’t on par with what other ecosystems provide.

Nonetheless, where there’s will there’s a way. In this Series of posts, I’m going to outline the setup I’m currently running. I’ll point to resources that helped me along the way and will describe how to combine the pieces to make it all fit together. I don’t plan publishing in any particular order and since business goes first, I am going to write when I find the time for it.

All posts of the series will be put into the category iOS Continous Integration Series, which also is the best place to find them.

The setup will consist of:
The Dev’s Private Cloud (aka a HyperV Server) hosting:
– Teamcity CI Server
– Build Agents
– Mercurial via hgweb.cgi

Kiwi for Acceptance Testing
OCMock as Isolation framework
GCov for Code Coverage

Planned Posts:

Running Ubuntu Server in HyperVi
Setting up a TeamCity Server on Ubuntu
Setting up a Mercurial Server
iOS Testing Frameworks revisited
Running OCUnit on a build agent
Connecting OCUnit to Teamcity
Integrating OCMock
Using Kiwi for Acceptance Testing
Retrieving Coverage information with GCov
XCode Alternatives

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