To create and checkout a branch in git :

> git branch version_0.9.3
> git checkout version_0.9.3

.. or if you have a better memory than me you can do it in one command :

> git checkout -b version_0.9.3

Now we’ve created the branch, committed a bunch of changes, and we want to push it to a remote repository. Regular git push doesn’t do anything :

> git push
Everything up-to-date

You have to specify the remote name where you want to push it to (usually origin, depending how you’ve configured things) :

> git push origin version_0.9.3
Total 0 (delta 0), reused 0 (delta 0)
To git@recurser.com:my_repository.git
 * [new branch]      version_0.9.3 -> version_0.9.3

The syntax to delete a remote branch is the part I always forget :

git push origin :version_0.9.3

> git branch -d version_0.9.3.

If you’re familiar with ruby, you should also checkout the git_remote_branch rubygem , which is designed to make working with remote branches easier.

> wget http://nginx.org/download/nginx-0.8.34.tar.gz
> tar xvzf nginx-0.8.34.tar.gz
> cd nginx-0.8.34

Next, configure it to support ssl, gzip, flv streaming and real-ip. I generally compile it to /opt/nginx-YYMMDD (change the —prefix setting if you want to put it somewhere else) :

> ./configure \
        --prefix=/opt/nginx-20100311 \
        --with-http_ssl_module \
        --with-http_gzip_static_module \
        --with-http_flv_module \
        --with-http_realip_module

At this point I got an error about missing PCRE – this Ubuntu installation is basically fresh so there’s a lot of stuff missing.

./configure: error: the HTTP rewrite module requires the PCRE library.
You can either disable the module by using --without-http_rewrite_module
option, or install the PCRE library into the system, or build the PCRE library
statically from the source with nginx by using --with-pcre=<path> option.

I had libpcre3 installed, but i needed libpcre3-dev as well.

> sudo aptitude install libpcre3-dev 
> ./configure \
        --prefix=/opt/nginx-20100311 \
        --with-http_ssl_module \
        --with-http_gzip_static_module \
        --with-http_flv_module \
        --with-http_realip_module

We get a bit further this time, but still no luck.

./configure: error: SSL modules require the OpenSSL library.
You can either do not enable the modules, or install the OpenSSL library
into the system, or build the OpenSSL library statically from the source
with nginx by using --with-openssl=<path> option.

This time it’s libssl-dev that’s missing :

> sudo aptitude install libssl-dev
> ./configure \
        --prefix=/opt/nginx-20100311 \
        --with-http_ssl_module \
        --with-http_gzip_static_module \
        --with-http_flv_module \
        --with-http_realip_module
.....
.....
.....
 
Configuration summary
  + using system PCRE library
  + using system OpenSSL library
  + md5: using OpenSSL library
  + sha1 library is not used
  + using system zlib library

Now that we’ve successfully configured it, we can compile and install :

> make 
> sudo make install

Now, make a symlink so you can switch to newer versions easily :

> sudo ln -s /opt/nginx-20100311 /opt/nginx

Finally, we want to set up a startup script. Create a file in /etc/init.d/nginx and paste the following in :

#! /bin/sh
 
### BEGIN INIT INFO
# Provides:          nginx
# Required-Start:    $all
# Required-Stop:     $all
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: starts the nginx web server
# Description:       starts nginx using start-stop-daemon
### END INIT INFO
 
PATH=/opt/nginx/sbin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
DAEMON=/opt/nginx/sbin/nginx
NAME=nginx
DESC=nginx
 
test -x $DAEMON || exit 0
 
# Include nginx defaults if available
if [ -f /etc/default/nginx ] ; then
	. /etc/default/nginx
fi
 
set -e
 
case "$1" in
  start)
	echo -n "Starting $DESC: "
	start-stop-daemon --start --quiet --pidfile /var/run/$NAME.pid \
		--exec $DAEMON -- $DAEMON_OPTS
	echo "$NAME."
	;;
  stop)
	echo -n "Stopping $DESC: "
	start-stop-daemon --stop --quiet --pidfile /var/run/$NAME.pid \
		--exec $DAEMON
	echo "$NAME."
	;;
  restart|force-reload)
	echo -n "Restarting $DESC: "
	start-stop-daemon --stop --quiet --pidfile \
		/var/run/$NAME.pid --exec $DAEMON
	sleep 1
	start-stop-daemon --start --quiet --pidfile \
		/var/run/$NAME.pid --exec $DAEMON -- $DAEMON_OPTS
	echo "$NAME."
	;;
  reload)
      echo -n "Reloading $DESC configuration: "
      start-stop-daemon --stop --signal HUP --quiet --pidfile /var/run/$NAME.pid \
          --exec $DAEMON
      echo "$NAME."
      ;;
  *)
	N=/etc/init.d/$NAME
	echo "Usage: $N {start|stop|restart|reload|force-reload}" >&2
	exit 1
	;;
esac
 
exit 0

This allows you to start/stop the server easily (although I find stop a bit flakey) :

> /etc/init.d/nginx stop
> /etc/init.d/nginx start

Finally, we want to make sure nginx launches at startup :

> sudo update-rc.d nginx defaults

Now you should be able to load http://yourserver.com/ and see nginx.

The last thing to do is enable the flv streaming module. You’ll need to add a rule to your nginx.conf something like the following :

location ~ \.flv$ {
	flv;
	root /path/to/your/flv/files;
}

Done!

1. Make sure only the Java SE 6 64-bit options are enabled (a word of caution – Flex Builder doesn’t work with these settings – you’ll need to change them back to use it).

2. You can check your java version by typing java -version in a terminal – you should get the following output.

> java -version
java version "1.6.0_17"
Java(TM) SE Runtime Environment (build 1.6.0_17-b04-248-9M3125)
Java HotSpot(TM) 64-Bit Server VM (build 14.3-b01-101, mixed mode)

3. Set JAVA_HOME so it matches your new java version

> export JAVA_HOME=/System/Library/Frameworks/JavaVM.framework/Versions/1.6/Home

4. You should now be able to build red5 :

> svn checkout http://red5.googlecode.com/svn/java/server/trunk/ red5-trunk
> cd red5-trunk
> make
ant dist
Buildfile: build.xml
.....
.....
.....
BUILD SUCCESSFUL
Total time: 2 minutes 31 seconds

5. Now you should be able to run your newly-built red5 server. Note – make sure you use the *.sh files that were created in the dist folder to run it:

> cd dist
> ./red5.sh
Running on  Darwin
Starting Red5
.....
.....
.....
[INFO] [Launcher:/installer] org.red5.server.service.Installer - Installer service created

6. Now you can copy this dist folder to wherever you want your red5 install to live – eg. /Applications/Red5

> cd ../
> cp -R dist /Applications/Red5

Once you get all this working, i recommend you install the eclipse red5 plugin , and create a red5 eclipse project if you’re interested in going further.

In Flex Builder, go to Preferences -> Flex -> Installed Flex SDKs. Click the Add… button and add your new 4.0 SDK to the list. If you like you can click the checkbox next to the new SDK and uncheck the others, to enable it by default.

• To update your project so it uses the new SDK, go to Project in the Flex Builder top menu, then select Properties -> Flex Compiler, and update the Require Flash Player Version: to 10.0.0

You should now be able to use some of the great new stuff from Flex 4, such as the new VideoPlayer component

<?xml version="1.0" encoding="utf-8"?>
<s:Application
	xmlns:fx="http://ns.adobe.com/mxml/2009" 
	xmlns:s="library://ns.adobe.com/flex/spark">
	
	<s:VideoPlayer 
		source="my_movie.flv"
		horizontalCenter="0"
		verticalCenter="0"
		autoPlay="false" />
	
</s:Application>

Initially ubuntu seems to have RubyGems 1.01 and 1.2.0 installed :

> gem --version
1.2.0
>/usr/bin/gem1.8 --version
1.2.0
>/usr/bin/gem1.9 --version
1.0.1

Unlike installation on OS X , the initial gem install worked fine :

> sudo gem install git-up
Successfully installed git-up-0.1.0
1 gem installed
Installing ri documentation for git-up-0.1.0...
Installing RDoc documentation for git-up-0.1.0...

Trying to actually use it, however, caused a few errors :

>  git up
/usr/local/lib/site_ruby/1.8/rubygems.rb:578:in `report_activate_error': Could not find RubyGem thoughtbot-shoulda (>= 0) (Gem::LoadError)
        from /usr/local/lib/site_ruby/1.8/rubygems.rb:134:in `activate'
        from /usr/local/lib/site_ruby/1.8/rubygems.rb:158:in `activate'
        from /usr/local/lib/site_ruby/1.8/rubygems.rb:157:in `each'
        from /usr/local/lib/site_ruby/1.8/rubygems.rb:157:in `activate'
        from /usr/local/lib/site_ruby/1.8/rubygems.rb:49:in `gem'
        from /usr/bin/git-up:18

This error persists even after installing shoulda :

>  sudo gem install shoulda
Successfully installed shoulda-2.10.3
1 gem installed
Installing ri documentation for shoulda-2.10.3...
Installing RDoc documentation for shoulda-2.10.3...

After my experience installing it on OS X, i decided the easiest way to move forward was probably to install RubyGems 1.3.1 :

> wget http://rubyforge.org/frs/download.php/45905/rubygems-1.3.1.tgz
> tar xzf rubygems-1.3.1.tgz
> cd rubygems-1.3.1
> sudo ruby setup.rb
.....
RubyGems installed the following executables:
        /usr/bin/gem1.8
 
If `gem` was installed by a previous RubyGems installation, you may need
to remove it by hand.
 
> gem -v
1.3.1
> sudo gem install git-up
Successfully installed git-up-0.1.0
1 gem installed
Installing ri documentation for git-up-0.1.0...
Installing RDoc documentation for git-up-0.1.0...

After this, trying to run git up caused a bunch of missing dependency errors, and I had to install gems for archive-tar-minitar, nokogiri (which also required installing libxslt-ruby), and rcov. Finally, I got stuck trying to install hoe :

> sudo gem install hoe                                                                                                                         1 ?
ERROR:  Error installing hoe:
        gemcutter requires RubyGems version >= 1.3.5

Let’s try all this again with RubyGems 1.3.5 :

> wget http://rubyforge.org/frs/download.php/60718/rubygems-1.3.5.tgz
> tar xvzf rubygems-1.3.5.tgz 
> cd rubygems-1.3.5 
> sudo ruby setup.rb
RubyGems installed the following executables:
        /usr/bin/gem1.8
> gem -v
1.3.5
> sudo gem -v
1.3.5
> sudo gem install git-up
Successfully installed git-up-0.1.0
1 gem installed
Installing ri documentation for git-up-0.1.0...
Installing RDoc documentation for git-up-0.1.0...
> git up
master              up to date

Finally with RubyGems 1.3.5, git-up works fine, with no dependency issues or missing gems.

> sudo gem install git-up
Updating metadata for 1 gems from http://gems.rubyforge.org
.
complete
ERROR:  could not find git-up locally or in a repository

I assume this is something to do with gem hosting moving to github or something… I haven’t really been following ruby for a year or so so I’m not sure exactly what’s going on. It seems i’m running a pretty old version of RubyGems , so I tried to update :

> gem --version
1.0.1
> sudo gem update
Updating installed gems...
Updating metadata for 1 gems from http://gems.rubyforge.org
.
complete
Nothing to update

After a little googling, the correct command turned out to be the following :

> sudo gem update --system
Updating RubyGems...
Updating metadata for 1 gems from http://gems.rubyforge.org
.
complete
Attempting remote update of rubygems-update
Successfully installed rubygems-update-1.3.5
1 gem installed
Installing ri documentation for rubygems-update-1.3.5...
Installing RDoc documentation for rubygems-update-1.3.5...
Could not find main page README
Could not find main page README
Could not find main page README
Could not find main page README
Updating version of RubyGems to 1.3.5
Installing RubyGems 1.3.5
RubyGems 1.3.5 installed
 
=== 1.3.5 / 2009-07-21
 
Bug fixes:
 
* Fix use of prerelease gems.
* Gem.bin_path no longer escapes path with spaces. Bug #25935 and #26458.
 
Deprecation Notices:
 
* Bulk index update is no longer supported (the code currently remains, but not
  the tests)
* Gem::manage_gems was removed in 1.3.3.
* Time::today was removed in 1.3.3.
 
 
------------------------------------------------------------------------------
 
RubyGems installed the following executables:
        /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/gem
 
RubyGems system software updated

Now with the more recent version, git-up installs fine :

> gem --version
1.3.5
> sudo gem install git-up
Successfully installed colored-1.2
Successfully installed diff-lcs-1.1.2
Successfully installed grit-2.0.0
Successfully installed git-up-0.1.0
4 gems installed
Installing ri documentation for colored-1.2...
Installing ri documentation for diff-lcs-1.1.2...
Installing ri documentation for grit-2.0.0...
Installing ri documentation for git-up-0.1.0...
Installing RDoc documentation for colored-1.2...
Installing RDoc documentation for diff-lcs-1.1.2...
Installing RDoc documentation for grit-2.0.0...
Installing RDoc documentation for git-up-0.1.0...

http {
    include       mime.types;
    default_type  application/octet-stream;
    sendfile        on;
    keepalive_timeout  65;
 
    server {
        client_max_body_size 20M;
        listen       80;
        server_name  localhost;
 
        # Main location
        location / {
            proxy_pass         http://127.0.0.1:8000/;
        }
    }
}

Makefile:22: *** missing separator.  Stop.

… make sure you are using real tabs instead of spaces. A global search and replace for four-spaces should fix things up.

======================================================================
ERROR: test_confirm_different_passwords (django.contrib.auth.tests.views.PasswordResetTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/dave/Documents/Code/python/loudgallery/django/contrib/auth/tests/views.py", line 124, in test_confirm_different_passwords
    'new_password2':' x'})
  File "/Users/dave/Documents/Code/python/loudgallery/django/test/client.py", line 313, in post
    response = self.request(**r)
  File "/Users/dave/Documents/Code/python/loudgallery/django/core/handlers/base.py", line 92, in get_response
    response = callback(request, *callback_args, **callback_kwargs)
  File "/Users/dave/Documents/Code/python/loudgallery/django/contrib/auth/views.py", line 141, in password_reset_confirm
    return render_to_response(template_name, context_instance=context_instance)
  File "/Users/dave/Documents/Code/python/loudgallery/django/shortcuts/__init__.py", line 20, in render_to_response
    return HttpResponse(loader.render_to_string(*args, **kwargs), **httpresponse_kwargs)
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/loader.py", line 108, in render_to_string
    return t.render(context_instance)
  File "/Users/dave/Documents/Code/python/loudgallery/django/test/utils.py", line 29, in instrumented_test_render
    return self.nodelist.render(context)
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/__init__.py", line 779, in render
    bits.append(self.render_node(node, context))
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/__init__.py", line 792, in render_node
    return node.render(context)
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/loader_tags.py", line 97, in render
    return compiled_parent.render(context)
  File "/Users/dave/Documents/Code/python/loudgallery/django/test/utils.py", line 29, in instrumented_test_render
    return self.nodelist.render(context)
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/__init__.py", line 779, in render
    bits.append(self.render_node(node, context))
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/__init__.py", line 792, in render_node
    return node.render(context)
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/__init__.py", line 946, in render
    autoescape=context.autoescape))
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/__init__.py", line 779, in render
    bits.append(self.render_node(node, context))
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/__init__.py", line 792, in render_node
    return node.render(context)
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/loader_tags.py", line 24, in render
    result = self.nodelist.render(context)
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/__init__.py", line 779, in render
    bits.append(self.render_node(node, context))
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/__init__.py", line 792, in render_node
    return node.render(context)
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/defaulttags.py", line 244, in render
    return self.nodelist_false.render(context)
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/__init__.py", line 779, in render
    bits.append(self.render_node(node, context))
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/__init__.py", line 792, in render_node
    return node.render(context)
  File "/Users/dave/Documents/Code/python/loudgallery/django/template/defaulttags.py", line 382, in render
    raise e
NoReverseMatch: Reverse for '<function index at 0x1ca9c30>' with arguments '()' and keyword arguments '{}' not found.

There were quite a few more of these, including :

test_activation_success_url (registration.tests.views.RegistrationViewTests) ... ERROR
test_activation_template_name (registration.tests.views.RegistrationViewTests) ... ERROR
test_registration_disallowed_url (registration.tests.views.RegistrationViewTests) ... ERROR
test_registration_extra_context (registration.tests.views.RegistrationViewTests) ... ERROR
test_registration_success_url (registration.tests.views.RegistrationViewTests) ... ERROR
test_registration_template_name (registration.tests.views.RegistrationViewTests) ... FAIL
test_registration_view_closed (registration.tests.views.RegistrationViewTests) ... ERROR
test_registration_view_failure (registration.tests.views.RegistrationViewTests) ... FAIL
test_registration_view_initial (registration.tests.views.RegistrationViewTests) ... FAIL
test_registration_view_success (registration.tests.views.RegistrationViewTests) ... ERROR
test_valid_activation (registration.tests.views.RegistrationViewTests) ... ERROR
...
test_confirm_complete (django.contrib.auth.tests.views.PasswordResetTest) ... FAIL
test_confirm_invalid (django.contrib.auth.tests.views.PasswordResetTest) ... FAIL
test_confirm_valid (django.contrib.auth.tests.views.PasswordResetTest) ... FAIL
...

<a href="{% url home.views.index}">Cancel</a>

For whatever reason, django doesn’t include my project’s various urls.py files when it runs its tests, so it doesn’t know anything about my URLs. After a few hours I found this solution , which is a little hack-y, but seems to work. Simply add as xxxx at the end of your url call, and output the url as a variable using (for example) {{ index }} . This seems to suppress the errors :

<a href="{% url home.views.index as index %}{{ index }}">Cancel</a>

EMAIL_USE_TLS = True
EMAIL_HOST = 'smtp.gmail.com'
EMAIL_HOST_USER = username@gmail.com'
EMAIL_HOST_PASSWORD = 'password'
EMAIL_PORT = 587 

(Obviously, substituting your own email and password)

You can also use an address at your own domain if you set the DNS records to use google apps.

To test if it’s working :

> python manage.py shell
>>> from django.core.mail import EmailMessage
>>> email = EmailMessage('Mail Test', 'This is a test', to=['test@your-address.com'])
>>> email.send()

First, download mysql-python from here .
Unzip and try to build it :

> tar xvzf MySQL-python-1.2.3c1.tar.gz
> cd MySQL-python-1.2.3c1
> sudo python setup.py build

If the build works, you’re in luck… you simply need to install it :

> sudo python setup.py install

More than likely though, it isn’t going to work :) At first, i got an error about _LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)_ :

running buildrunning build_py
copying MySQLdb/release.py -> build/lib.macosx-10.5-i386-2.5/MySQLdb
running build_ext
building '_mysql' extension
/usr/bin/gcc-4.0 -fno-strict-aliasing -Wno-long-double -no-cpp-precomp -mno-fused-madd -fno-common -dynamic -DNDEBUG -g -fwrapv -O3 -Wall -Wstrict-prototypes -Dversion_info=(1,2,3,'gamma',1) -D__version__=1.2.3c1 -I/usr/local/mysql-5.1.30-osx10.5-x86_64/include -I/opt/local/Library/Frameworks/Python.framework/Versions/2.5/include/python2.5 -c _mysql.c -o build/temp.macosx-10.5-i386-2.5/_mysql.o -g -Os -arch x86_64 -fno-common -D_P1003_1B_VISIBLE -DSIGNAL_WITH_VIO_CLOSE -DSIGNALS_DONT_BREAK_READ -DIGNORE_SIGHUP_SIGQUIT -DDONT_DECLARE_CXA_PURE_VIRTUAL
In file included from /opt/local/Library/Frameworks/Python.framework/Versions/2.5/include/python2.5/Python.h:57,
                 from pymemcompat.h:10,
                 from _mysql.c:29:
/opt/local/Library/Frameworks/Python.framework/Versions/2.5/include/python2.5/pyport.h:761:2: error: #error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."
In file included from _mysql.c:36:
/usr/local/mysql-5.1.30-osx10.5-x86_64/include/my_config.h:1104:1: warning: "SIZEOF_LONG" redefined
In file included from /opt/local/Library/Frameworks/Python.framework/Versions/2.5/include/python2.5/Python.h:8,
                 from pymemcompat.h:10,
                 from _mysql.c:29:
/opt/local/Library/Frameworks/Python.framework/Versions/2.5/include/python2.5/pyconfig.h:814:1: warning: this is the location of the previous definition
error: command '/usr/bin/gcc-4.0' failed with exit status 1

To get around this, edit the file mentioned in the error ( /opt/local/Library/Frameworks/Python.framework/Versions/2.5/include/python2.5/pyport.h ) and comment out the line mentioned in the error (line 761 in the current version) :

/* 04-Oct-2000 LONG_BIT is apparently (mis)defined as 64 on some recent
 * 32-bit platforms using gcc.  We try to catch that here at compile-time
 * rather than waiting for integer multiplication to trigger bogus
 * overflows.
 */
/*#error "LONG_BIT definition appears wrong for platform (bad gcc/glibc config?)."*/

At this point, hopefully you can build and install without problems :

> sudo python setup.py build
> sudo python setup.py install

Even after i managed to install it, i continued to get the following error :

django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module: dynamic module does not define init function (init_mysql)

We need to uninstall the 64-bit version first. I found some great instructions on akrabat.com :

To uninstall MySQL and completely remove it from you Mac do the following:
 
    * sudo rm /usr/local/mysql
    * sudo rm -rf /usr/local/mysql*
    * sudo rm -rf /Library/StartupItems/MySQLCOM
    * sudo rm -rf /Library/PreferencePanes/My*
    * edit /etc/hostconfig and remove the line MYSQLCOM=-YES-
    * sudo rm -rf /Library/Receipts/mysql*
    * sudo rm -rf /Library/Receipts/MySQL*
 
The last two lines are particularly important as otherwise, you can't install an older version of MySQL even though you think that you've completely deleted the newer version!

Once this is done, download and install the Mac OS X 10.5 (x86) version from the mysql site (make sure you don’t get the x86_64 version again!), and with a bit of luck everything should be working.

> sudo port install scala  
> sudo port install maven2

> mkdir -p Documents/code/scala
> cd Documents/code/scala
> git clone git://github.com/dpp/liftweb.git
> cd liftweb
>  mvn clean:clean install

At this point i got an error :

Required goal not found: org.apache.maven.plugins:maven-archetype-plugin:jar in org.apache.maven.plugins:maven-archetype-plugin:1.0-alpha-7

[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESSFUL
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 7 minutes 50 seconds
[INFO] Finished at: Tue Aug 18 03:47:19 JST 2009
[INFO] Final Memory: 50M/63M
[INFO] ------------------------------------------------------------------------
mvn clean:clean install  360.40s user 51.08s system 87% cpu 7:50.98 total

Next, it’s time to create our new project :

> cd ..
> mvn archetype:create -U  \
 -DarchetypeGroupId=net.liftweb                             \
 -DarchetypeArtifactId=lift-archetype-basic                 \
 -DarchetypeVersion=1.0                            \
 -DremoteRepositories=http://scala-tools.org/repo-releases  \
 -DgroupId=net.liftweb.hello -DartifactId=hello-lift

> cd hello-lift/
> mvn install jetty:run

I could do this easily enough in code with multiple queries, but it seemed like a nice challenge to try and find a pure-sql alternative.

First attempt

This was based on an idea from the mysql forums :

SELECT u.login, a.filename FROM users u 
LEFT JOIN (SELECT filename, user_id, id AS rand_id FROM assets GROUP BY user_id ORDER BY RAND()) a 
ON u.id = a.user_id 
WHERE a.filename IS NOT NULL
ORDER BY u.login;

Since the ‘order by rand()’ happens after the ‘group by’, it doesn’t return random results – it always returns the same results, but in random order.

Second attempt

Apparently this is known as the MAX-CONCAT trick :

SELECT u.login, user_id, SUBSTRING(MAX(CONCAT(TRUNCATE(RAND(),4),a.id)),7) AS asset_id 
FROM assets a 
LEFT JOIN users u ON a.user_id = u.id 
WHERE user_id IS NOT NULL
GROUP BY user_id 
ORDER BY user_id;

This works, however it’s pretty hacky and very MySQL-specific, and I doubt it will work on any other databases. Depending on the number of rows you want to return, it could well end up being faster just doing the heavy lifting in code rather than trying to bend SQL to your will.

Update – Solution (2009/12/04)

Ronnii commented and pointed out this approach which (as far as i can tell) seems to do exactly what i wanted.

SELECT u.login, a.filename FROM users u 
JOIN (SELECT filename, user_id, id AS rand_id FROM assets ORDER BY RAND()) a
ON u.id = a.user_id 
WHERE a.filename IS NOT NULL
GROUP BY user_id
ORDER BY u.login;

Thanks Ronni!

Luckily, nginx provides a HTTP X-Forwarded-For header containing the clients real IP address, although apache doesn’t pick it up by default. To allow apache to recognize the original client IP, we need to install the mod_rpaf module. On ubuntu, this is as simple as installing a package :

> sudo apt-get install  libapache2-mod-rpaf

Once you have installed mod_rpaf, you need to configure apache. Add something similar to the following to your apache config (alter the RPAFproxy_ips setting as appropriate to match the IP address(es) of your nginx server(s) :

<IfModule mod_rpaf.c>
RPAFenable On
RPAFsethostname On
RPAFproxy_ips 127.0.0.1
</IfModule>

If you installed the ubuntu package, this should be set up for you automatically in /etc/apache2/mods-available/rpaf.conf .

Once apache is restarted, you should be able to see the correct IP addresses in the apache access logs.

If nginx has trouble passing the X-Forwarded-For header for some reason, you can try to force it to set headers by hand :

...
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
...

First, download the latest version of nginx (0.7.61 at the time of writing) :

> wget http://sysoev.ru/nginx/nginx-0.7.61.tar.gz 
> tar xvzf nginx-0.7.61.tar.gz
> cd nginx-0.7.61

Changing the server string

The server header is in a file called ngx_http_header_filter_module.c :

> vi src/http/ngx_http_header_filter_module.c

Edit the following line (currently line 48 in version 0.7.61) :

static char ngx_http_server_string[] = "Server: nginx" CRLF;

… and change the nginx in ‘Server: nginx’ to whatever you want:

static char ngx_http_server_string[] = "Server: recurser" CRLF;

Next, edit src/core/nginx.h :

> vi src/core/nginx.h

Edit the following line (currently line 13 in version 0.7.61) :

#define NGINX_VER          "nginx/" NGINX_VERSION 

… and change the server string to whatever you want:

#define NGINX_VER          "recurser/" NGINX_VERSION 

Changing the version number

You might also want to change the version number to confuse attackers, or just for fun :) Edit src/core/nginx.h :

> vi src/core/nginx.h

Edit the following line (currently line 12 in version 0.7.61) :

#define NGINX_VERSION      "0.7.61" 

… and change the version to whatever you want:

#define NGINX_VERSION      "1.0" 

You can stop nginx from displaying the version entirely if you want, by including the server_tokens directive in your nginx.conf :

server_tokens off;

Compiling

You can set the prefix as appropriate – I keep it in /opt/ on Ubuntu.

> ./configure --prefix=/opt/nginx-0.7.61 --with-http_ssl_module
> make
> sudo make install

After this, use .bashrc or similar to add /opt/nginx-0.7.61/sbin to your path, then you can start your new nginx install using :

> sudo ngingx

To stop it, use ‘-s’ to send the stop signal :

> sudo nginx -s stop

Results

If you check the reponse headers, you should see your custom server string :

Server: recurser/1.0, recurser
Date: Tue, 11 Aug 2009 02:47:31 GMT
Content-Type: text/html; charset=UTF-8
Transfer-Encoding: chunked
Connection: keep-alive
X-Powered-By: PHP/5.2.4-2ubuntu5.6
X-Pingback: http://recurser.com/xmlrpc.php
Expires: Tue, 18 Aug 2009 02:47:31 GMT
Last-Modified: Tue, 11 Aug 2009 02:47:31 GMT
Cache-Control: max-age=604800
Pragma: no-cache
Content-Encoding: gzip