afurlan's blog

Today I moved the people.nullable.org from Apache to the Nginx and the migration was easier than I expected.

The configuration is very simple so I'll jump directly to the code. The following lines enables the Apache's Userdir feature with PHP support in a specific domain. As in my last post, I'm assuming you currently have PHP working on Nginx but if you don't, take a look at here to know how to do that using the spawn-fcgi.

server {
    server_name people.nullable.org;
    listen 80;
    listen 443;

    # directory root
    root /srv/people.nullable.org/nginx/www;
    index index.php index.html index.htm;

    # userdir redirection
    location ~ ^/~([^/]+)/(.+\.php)$ {
            if (!-f /home/$1/public_html/$2) {
                    rewrite ^ 404;
            }
            alias /home/$1/public_html/$2;
            fastcgi_pass 127.0.0.1:9000;
            fastcgi_index index.php;
            fastcgi_param SCRIPT_FILENAME $request_filename;
            include fastcgi_params;
    }
    location ~ ^/~([^/]+)(/.*)?$ {
            alias /home/$1/public_html$2;
            autoindex on;
    }

    # logging
    error_log /srv/people.nullable.org/nginx/log/access.log;
    access_log /srv/people.nullable.org/nginx/log/access.log;
}

There isn't too much to say, this setup is currently running on my server. Suggestions are welcomed! :)

I usually run Apache in my web servers, it works pretty well but spends too much memory for that. So I decided to give a try to the Nginx and for now, I'm really impressed about its preformance.

I don't intend to present Nginx at this post, but if you want to know more about it (and IMHO, you should) go to its official documentation. I'm going to show how to configure the PhpLdapAdmin and Nginx but not how to install the PHP itself. So I'll presume you currently have PHP working on Nginx but if you don't, take a look at here to know how to do that using the spawn-fcgi.

Let's start installing the PhpLdapAdmin and the PHP5 module to connect to the LDAP server. If you're using Debian/Ubuntu, all new software are just an "aptitude install" of distance from you, so let's install them:

$ aptitude install phpldapadmin php5-ldap

Now we can start the PhpLdapAdmin on Nginx configuration itself... You can use the PhpLdapAdmin under a specific domain or use it as a standalone application. If you want to install the PhpLdapAdmin under a specific domain, you should create a new virtual host named example.com as follows:

$ vim /etc/nginx/sites-available/example.com
server {
    server_name example.com;
    listen 80;

    # document root
    root /usr/share/phpldapadmin/htdocs;
    index index.php index.html index.htm;

    # application: phpldapadmin
    location ~ \.php$ {
            fastcgi_pass 127.0.0.1:9000;
            fastcgi_index index.php;
            fastcgi_param  SCRIPT_FILENAME  $document_root/$fastcgi_script_name;
            include fastcgi_params;
            fastcgi_param HTTPS on;
    }

    # logging
    error_log /srv/example.com/nginx/log/error.log;
    access_log /srv/example.com/nginx/log/access.log;
}

Or if you want to install the PhpLdapAdmin as a standalone application, you should create a new virtual host as follow:

$ vim /etc/nginx/sites-available/example.com
server {
    server_name example.com;
    listen 80;

    # document root
    root /srv/example.com/nginx/www;
    index index.php index.html index.htm;

    # application: phpldapadmin
    location /phpldapadmin {
            alias /usr/share/phpldapadmin/htdocs;
            index index.php index.html index.htm;
    }
    location ~ ^/phpldapadmin/.*\.php$ {
            root /usr/share;
            if ($request_filename !~* htdocs) {
                    rewrite ^/phpldapadmin(/.*)?$ /phpldapadmin/htdocs$1;
            }
            fastcgi_pass 127.0.0.1:9000;
            fastcgi_index index.php;
            fastcgi_param SCRIPT_FILENAME $request_filename;
            include fastcgi_params;
    }

    # logging
    error_log /srv/example.com/nginx/log/error.log;
    access_log /srv/example.com/nginx/log/access.log;
}

And now, we can just enable the new virtual host and restart Nginx:

$ cd /etc/nginx/sites-enabled
$ ln -s ../ldap.example.com
$ /etc/init.d/nginx restart

No, this blog isn't running over nginx (yet). It's a Python (Django) application, so I want to migrate it ASAP and test a new setup based on Nginx + Gunicorn following a recomendation of Osvaldo Santana... but for now, that's all. :)

As always: if you found some english bug, warn me and I'll be glad to fix it. :)

Some time ago I changed my default shell to use IPython instead of Bash. The IPython is a really great shell and IMHO has great advantages but for those who, like me, are completely addicted to the clear command, the IPython's clear is a huge disadvantage.

In IPython, the clear command clear varios data like input, output and directory histories but it doesn't clear the screen! You can take a look at the documentation of default function for the clear command below and see how it works:

afurlan@merlin:~$ from IPython.Extensions.clearcmd import clear_f
afurlan@merlin:~$ print clear_f.__doc__
 Clear various data (e.g. stored history data)

    %clear out - clear output history
    %clear in  - clear input history
    %clear shadow_compress - Compresses shadow history (to speed up ipython)
    %clear shadow_nuke - permanently erase all entries in shadow history
    %clear dhist - clear dir history

afurlan@merlin:~$

So I created a new function to extend the first one adding the option to clear the screen when no args were passed. If you'd like to do the same, add the following lines in your ~/.ipython/ipy_user_conf.py:

def new_clear_f(*args, **kwargs):
    ''' Extend the default clear function adding the option to
    clear the screen when no args were passed.'''
    if not args[1]:
            ip.system('clear')
    else:
            from IPython.Extensions.clearcmd import clear_f
            clear_f(*args, **kwargs)
            ip.expose_magic('clear', new_clear_f)
ip.expose_magic('clear', new_clear_f)

And now it all seems clear again. :)

As always: if you found some english bug, warn me and I'll be glad to fix it. :)

If you are a shell addicted person and like Python, then the IPython was made just for you! The IPython provides a very usefull feature (that may looks a bit strange at first) of mixing Python and Shell commands in a easy and intuitive way. I don't pretend to say why you should use IPython instead of your current shell but I think that, if you know Python, you should prefer to write Python code instead of Bash code.

I'll assume that you already have the IPython installed but if you don't, take a look at IPython's documentation to see how to install it. I'm running Debian and my setup is focused in my machine, so it should work for the most of the others linux distros but if you are running a different system, I'm sorry for you you may have to adapt some commands and/or paths. :)

Configuring the IPython's prompt

The first time you run IPython, it displays a warning about the creation of your personal configuration directory. One of the most important parts of this warning is about the new configuration file: ~/.ipython/ipy_user_conf.py. So let's configure this file and the IPython's prompt to make it looks exactly like the Debian's prompt. Edit your configuration file and change the following settings as below:

...
import ipy_profile_sh
...
o.prompt_in1 = r'\C_Normal\u@\H:\Y2$ '
o.prompt_in2 = r'\C_Normal... '
...

The first option, import ipy_profile_sh, avoid you to have to escape all the Bash commands. The second and third options, o.prompt_in1 and o.prompt_in2, change the IPython's prompt. And now start the IPython as follow:

afurlan@merlin:~$ ipython -nosep -nobanner -noconfirm_exit
afurlan@merlin:~$
afurlan@merlin:~$ 
afurlan@merlin:~$ print 'hello python!'
hello python!
afurlan@merlin:~$ echo 'hello bash!'
hello bash!

Now you're able to run Python commands:

afurlan@merlin:~$ for line in open('domains.txt'):
              ...     print line
              ...    
              ...    
afurlan.org

blog.afurlan.org

And a mixed of Python and Bash commands:

afurlan@merlin:~$ for line in open('domains.txt'):
              ...     echo "$line"
              ...    
              ...    
afurlan.org

blog.afurlan.org

afurlan@merlin:~$ for line in open('domains.txt'):
              ...     echo "$line.strip()"
              ...    
              ...    
afurlan.org
blog.afurlan.org

Setting the IPython as your default shell

Actually I don't like to set the IPython as my default shell... I use to run screen so I configure it to open five IPython sessions by default but if you really like to set it as your default shell, you can add the following line at the end of your ~/.bashrc file:

...
exec ipython -nosep -nobanner -noconfirm_exit

If you're a screen user too, you can add the following lines at your ~/.screenrc:

...
# open 5 ipython sessions by default
screen -t p 1 ipython -nosep -nobanner -noconfirm_exit
screen -t p 2 ipython -nosep -nobanner -noconfirm_exit
screen -t p 3 ipython -nosep -nobanner -noconfirm_exit
screen -t p 4 ipython -nosep -nobanner -noconfirm_exit
screen -t p 5 ipython -nosep -nobanner -noconfirm_exit
...

Or, if you like, you can also get my current .screenrc file.

And, as always: if you found some english bug, warn me and I'll be glad to fix it. :)