With this post I will explain you the Puppet Configuration Key feature at the server manager.

With the puppet configuration key feature you can store configuration data used in puppet classes at your database. You can also store configuration data on server groups and add servers to that group.

Yes - it's working like ripienaar's great extlookup but with database.

For this example I have got two hosts:

• valentina.brachium-system.net


• web01.brachium-system.net

Both hosts are saved on the server manager.

We have some puppet configuration keys at server manager:



The first server valentina.brachium-system.net has got the following puppet key configuration:




The second server web01.brachium-system.net has got the following puppet key configuration:



We are using this puppet manifest:

# Configuration for dblookup from servermgmt:
$dblook_host = "localhost"
$dblook_user = "servermgmt"
$dblook_pass = "servermgmt"
$dblook_db = "servermgmt"


class ssh::server {
$ssh_server_password_authentication = dblookup('ssh_server_password_authentication')
$ssh_server_root_login = dblookup('ssh_server_root_login')
notice("ssh_server_password_authentication: $ssh_server_password_authentication")
notice("ssh_server_root_login: $ssh_server_root_login")
file { "/etc/ssh/sshd_config":
content => template("/home/jonas/puppet/templates/sshd_config.erb")
}
}


node default {
$pkg_install_subversion = dblookup('pkg_install_subversion')
notice("We are the server: ${fqdn}")
notice("pkg_install_subversion: $pkg_install_subversion")
include ssh::server
package {"subversion":
ensure => dblookup('pkg_install_subversion')
}
}

We run that manifest on the server valentina:

notice: Scope(Node[default]): We are the server: valentina.brachium-system.net
notice: Scope(Node[default]): pkg_install_subversion: present
notice: Scope(Class[ssh::server]): ssh_server_password_authentication: yes
notice: Scope(Class[ssh::server]): ssh_server_root_login: no

We run that manifest on the server web01:

notice: Scope(Node[default]): We are the server: web01.stg.brachium-system.net
notice: Scope(Node[default]): pkg_install_subversion: absent
notice: Scope(Class[ssh::server]): ssh_server_password_authentication: no
notice: Scope(Class[ssh::server]): ssh_server_root_login: yes

You can see on the verbose output from puppet, the information is fetched from the database - if the server has got no own value for one key, the default value is used.

You can get the source at http://github.com/hggh/servermgmt

An really cool advertising postcard from airberlin airline, seen at an pub in Stuttgart:

If you manage some servers you need to document, which server has got which ip address. I have written an small webapp for that stuff. You can create companies, networks and servers.

One server could have one operation system, one server type (like hardware or virtual) and the mac/ip addresses. For every operation system you can save an preseed configuration for debian installation.


Some screenshots of the app:



--------------

Update:


It works like the extlookup, but not with files - it does an database lookup.
--------------

Planed features:

- authentication
- connect virtual servers to hardware nodes
- ...

Playing with nginx. Here are some random hints:

1.) nginx with php:

/usr/bin/spawn-fcgi -a 127.0.0.1 -p 9000 -u www-data -g www-data -f "/usr/bin/php-cgi -c /etc/php5/cgi/php-nginx.ini" -P /var/run/fcgi-php.pid

2.) Deny access to .svn directories:

location ~ \.svn { deny all; }

3.) rewrite urls

if ( !-f $request_filename ) {
rewrite ^/images/([A-Za-z]+)\/(.*)$ /images/default/$2 break;
}

The rewrite rule will redirect /images/bar/foo.png if it does not exists to /images/default/foo.png

spwan-fcgi is included in the lighttpd package if you are using lenny. On squeeze and sid spawn-fcgi is an standalone package!

Rest in peace perldoc.perl.org. You was so excellent with your online search and code highlighting. But after the redesign Web 2.0 is gone into perldoc. This is really bad. The old layout was so great.

The new design has got some scrolling bugs ( scroll fast to bottom, than you see double boxes of text) and the manual text is too often broken into newlines.

Please have a look: The good old one and the new one. Both pages displays the same content, but the old layout has got more free space and better overview.

You can use Arduino with Ethernetshield to fetch temperatures over network.

I have created an little sketch for Arduino. This sketch has got an "telnet" server. If you connect to the IP address of the arduino, you will get the temperature from all connected DS1820 sensors.



The DS1820 sensor is build in the 6.2 inch female plug. I have only two sensors connected, but you can connect more sensors to the One Wire Bus. It works like the old digitemp system. But digitemp needs an serial connector. My Arduino works via Network - that's really cool!

I also created an munin plugin for this Arduino system. If you edit /etc/munin/plugin-conf.d/munin-node you can supply alias names for the hex address of the sensor.

[arduino_ds1820_192.168.1.3]
env.101f9dca18020 Jonas desk
env.105269ca180a6 PC power supply
timeout 60

You have to insert the timeout 60 because the system fetches the temperature from the sensors just in time, this needs some time

If you have an catchall http virtual host like this:

<VirtualHost *:80 >
ServerName catchall.example.org
ServerAlias *.catchall.example.org
</VirtualHost>

You can log every virtual host on *. with:

LogFormat "%h - %v - %V %U" aliaseslog
CustomLog /var/log/apache2/catchall.example_aliases.log aliaseslog

An access to foo.catchall.example.org/test.html will be logged:

123.123.123.123 - catchall.example.org - foo.catchall.example.org /test.html

With the log file you can count the access:

cut -f 5 -d ' ' /var/log/apache2/catchall.example_aliases.log| sort | uniq -c | sort -n

This will tell you, the overall access to every host.

Useful links for converting filenames from one encoding to another:

• http://www.j3e.de/linux/convmv/


• http://hektor.umcs.lublin.pl/~mikosmul/computing/articles/linux-unicode.html

convmv is also available at debian. But I suggest you to use alway the newest version of convmv.

convmv, recursively converting filenames from ISO-8859-15 to UTF-8:

convmv -r --notest -f ISO-8859-15 -t UTF-8 /home