On MacOSX, if you have installed macports with the package installer, you may encounter the sudo: port: command not found problem.
Macports binaries are installed in /opt/local/bin, so you just need to add this path to your PATH environment variable. Example with your user, add to your $HOME/.profile :
export PATH=$PATH:/opt/local/bin
You can source your profile file to update your environment:
$ source .profile
You are now able to use the port command:
$ sudo port -v selfupdate
Tags: MacOSX, port, shell
The dmidecode command gives you all informations available about your memory.
With the special parameter “-t 16″, you can see the maximum (physical) memory that your server can have:
$ dmidecode -t 16
# dmidecode 2.8
SMBIOS 2.4 present.
Handle 0x1000, DMI type 16, 15 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: Multi-bit ECC
Maximum Capacity: 32 GB
Error Information Handle: Not Provided
Number Of Devices: 8
Here we can see that your server can handle up to 32Gb
Check empty memory slots
To know which slots are used or not use the “-t 17″ flag.
dmidecode -t 17 | grep Size
Size: 2048 MB
Size: 2048 MB
Size: No Module Installed
Size: No Module Installed
Size: No Module Installed
Size: No Module Installed
Size: No Module Installed
Size: No Module Installed
Links
Tags: dmidecode, memory
apticron is a shell script that send you an email report when new packages are available on your debian server.
Install apticron
As root, do:
apt-get install apticron
apticron configuration via /etc/apticron/apticron.conf
To receive reports on your email change the EMAIL variable in the configuration file. By default, reports are sent to the root user.
EMAIL="root" -> EMAIL="you@domain.com"
Reports received
Now apticron will send you reports like this:
apticron report [Sat, 26 Jul 2008 06:45:47 +0200]
==============================================
apticron has detected that some packages need upgrading on:
localhost.localdomain
[ 127.0.0.1 XXX.XXX.XXX.XXX ]
The following packages are currently pending an upgrade:
lighttpd 1.4.13-4etch10
========================================================================
Package Details:
Reading changelogs...
--- Changes for lighttpd ---
lighttpd (1.4.13-4etch10) stable-security; urgency=low
[ Pierre Habouzit ]
* Non-maintainer upload.
* Fix [CVE-2008-1531] patches mess, and add a missing hunk of the patch.
-- Thijs Kinkhorst thijs debian org Tue, 22 Jul 2008 12:19:10 +0200
========================================================================
You can perform the upgrade by issuing the command:
aptitude dist-upgrade
as root on localhost.localdomain
It is recommended that you simulate the upgrade first to confirm that the actions that
would be taken are reasonable. The upgrade may be simulated by issuing the command:
aptitude -s -y dist-upgrade
--
apticron
Apticron files
For more informations, you can have a look to those files:
/etc/cron.daily/apticron
/usr/sbin/apticron
Tags: apticron, debian, linux
When you put your website in maintenance mode, it’s a good idea to return a HTTP 503 error code to the client.
This code indicates that “the server is currently unable to handle the request due to a temporary overloading or maintenance of the server”.
The 503 code is used to avoid crawlers or caching proxy use the maintenance page as the new valid content for the request. You certainly don’t want Google save this content in his search index as the content of your website 
To achieve this we will use a rewrite rule in lighttpd to redirect all requests to a single PHP script which will return a 503 error code and print an informative message.
Lighttpd configuration
url.rewrite = ( "" => "/maintenance.php" )
This configuration will redirect any request to maintenance.php script.
If you need to serve an image in your maintenance page, you have to add another rule to the rewrite process like that :
url.rewrite = ( "upgrading.png" => "$0",
"" => "/maintenance.php" )
Let some users see the website
It might be usefull to let admins or developers access the website during the maintenance.
For that, you can disable the maintenance rewrite rule for certain IP addresses :
$HTTP["remoteip"] != “192.168.1.42″ {
url.rewrite = ( "upgrading.png" => "$0",
"" => "/maintenance.php" )
}
PHP code example
<?php
header("HTTP/1.1 503 Service Unavailable");
?>
We're currently upgrading our servers...
Links
Tags: lighttpd, php
To rotate your nginx log files, you can use the log file handler provided by FreeBSD: newsyslog.
Configuring /etc/newsyslog.conf
/var/log/nginx-access.log 644 7 1024 * JC /var/run/nginx.pid
/var/log/nginx-error.log 644 7 1024 * JC /var/run/nginx.pid
Before log rotation:
-rw-r--r-- 1 root wheel 104278002 Jul 16 11:35 nginx-access.log
-rw-r--r-- 1 root wheel 1509531 Jul 16 11:17 nginx-error.log
After log rotation:
-rw-r--r-- 1 root wheel 967 Jul 16 12:42 nginx-access.log
-rw-r--r-- 1 root wheel 5310443 Jul 16 12:41 nginx-access.log.0.bz2
-rw-r--r-- 1 root wheel 77 Jul 16 12:41 nginx-error.log
-rw-r--r-- 1 root wheel 37552 Jul 16 12:41 nginx-error.log.0.bz2
Links
Tags: FreeBSD, newsyslog, nginx
If you want to redirect visitors that access your website without the ‘www’, you can use mod_redirect with the following syntax:
$HTTP[”host”] =~ “^lescampeurs\.org” {
url.redirect = (
”^/(.*)$” => “http://www.lescampeurs.org/$1″
)
}
Links:
Tags: lighttpd
On the other hand, Dean seemingly thinks clusters of 1,800 servers are pretty routine, if not exactly ho-hum.
… that would mean Google has more than 200,000 servers, …
Co-founder Larry Page encourages a “healthy disrespect for the impossible” at Google
Dean described three core elements of Google’s software: GFS, the Google File System, BigTable, and the MapReduce algorithm.
Read it at CNET
Tags: google
Cronolog is log rotation program which gives you a lot of options to template the log destination files. The common use is to split logs by year / month / day.
Here is how to configure Apache to send log entries to cronolog :
CustomLog "|/usr/sbin/cronolog /home/log/apache2/%Y-%m-%d_domain.com_access.log" combined
This will create a log file named 2008-06-02_domain.com_access.log for today.
Cronolog reads log entries from standard input and writes them to the output file specified by your template.
More examples
CustomLog "|/usr/sbin/cronolog /home/log/apache2/%Y-%m_domain.com_access.log" combined
CustomLog "|/usr/sbin/cronolog /home/log/apache2/%Y-%W_domain.com_access.log" combined
CustomLog "|/usr/sbin/cronolog /home/log/apache2/%H_domain.com_access.log" combined
Links
Tags: apache, cronolog
If you’re using SVN to control your web application, your certainly need to deny access to .svn sub-directories.
With Apache2
<DirectoryMatch "^/.*/\.svn/">
Order allow,deny
Deny from all
</DirectoryMatch>
With lighttpd
$HTTP["url"] =~ "/\.svn/" {
url.access-deny = ( "" )
}
Tags: apache, lighttpd, svn
Sometimes you need to retrieve a single file from SVN without doing a checkout on the repository.
SVN provides the svn cat to output the content of a file. You can redirect the output to get the file as :
svn cat https://svn.mydomain.com/project/folder/file.ext > file.ext
You can also use a simple shell script to do the work :
$ cat svnget
#!/bin/sh
if [ -z "$1" ]; then
echo
echo "Usage : $0 <SVN-URL>"
echo
exit
fi
fn=`basename $1`
svn cat $1 > $fn
Tags: svn