cestdelamerde.com - linux

Apache Virtual Hosts and DNS Web Redirection

nospam@example.com (philou) — Tue, 12 Aug 2008 15:54:15 +0200

A friend of mine tried to setup some days ago an Apache web server with two virtual hosts. Unfortunately, he was only able to reach it's first defined virtual host. We found nothing bad in the Apache conf files. So we suspected an Apple conspiracy as the server was launched from an mac mini.

But it was not a conspiracy

He was using Gandi as registrar, DNS provider and registered what Gandi calls DNS Web Redirection : you hosts your zone on gandi DNS servers, all subdomain (eg www or blog) are recorded as a CNAME of webredir.vip.gandi.net. Then webredir.vip.gandi.net acts as a proxy to the real website of your choice (eg: a Mac Mini behind a Free DSL connection).

This method DOES NOT WORK when the target website uses Apache Virtual Hosts. (wrong Host header)

Do not use those kind of hacky redirection unless there is no other choice available. Use A and CNAME records, like cestdelamerde does :



@ 10800 IN A 217.70.191.204 

* 10800 IN CNAME cestdelamerde.com.

The ultimate DNS zone file if you are hosting all you're VH under the same IP...

Unbelievable Debian Security Issue

nospam@example.com (philou) — Thu, 15 May 2008 15:16:50 +0200

Two days ago, Debian developpers annouced a huge security breach has been introduced in libssl since september 2006 as a patch to the random number generator ([DSA 1571-1] New openssl packages fix predictable random number generator ; Debian -- Security Information -- DSA-1571-1 openssl).

Unfortunately, this unstable version of libssl is the one used for a while in Debian based distributions like Ubuntu, thus all debian or Ubuntu, Kubuntu, Xubuntu (...) users are required to upgrade their version of libssl and also check all key material generated since 2006

For Gentoo users, nothing has to be done ; their non patched openssl version is ok.

Again, a new reason for not using any debian based distributions... Gentoo rocks.

Firefox and Color Management

nospam@example.com (philou) — Sat, 15 Mar 2008 17:17:07 +0100

While I was uploading pictures from Lightroom to the web (flickr), I used firefox on OS X to preview uploaded galleries and colors of uploaded picture were insipid. I've first suspected Lightroom to create fucked jpeg files, but viewing with another web browser like Safari just shows perfect colors.

It seems that the Mac OS X version of Firefox 2 is not able to apply right color profiles to render jpeg pictures. The screenshot below is self explanatory...

The only workaround is not to use Firefox !

Monitoring Bandwidth from Command Line

nospam@example.com (philou) — Thu, 14 Feb 2008 14:10:20 +0100

First option :
{code}cat /proc/net/dev{code}

This shows all network interfaces and some statistics associated with them, but is not very user friendly.

User friendly option : install Bandwidth Monitor NG (package name is bwm-ng in most common distribution) and execute it :
{code}bwm-ng{code}

Flush Linux Caches

nospam@example.com (philou) — Thu, 14 Feb 2008 09:47:49 +0100

It is now possible from kernel version 2.6.16 to drop Linux internal caches (page caches, inodes and dentry caches). This can be done by echoing a number into /proc/sys/vm/drop_caches :

To drop page cache :
echo 1 > /proc/sys/vm/drop_caches

To drop inode and dentry cache :
echo 2 > /proc/sys/vm/drop_caches

And finally to drop everything :
echo 3 > /proc/sys/vm/drop_caches

Source : Drop Caches - linux-mm.org

KDE 4.0 Final - A Pre-Alpha Release ?

nospam@example.com (philou) — Mon, 28 Jan 2008 10:41:30 +0100

January 11, 2008 kde.org annouced KDE 4.0 is released !

Unfortunately, this release is not really ready for day to day use.

The new interface is beautyful but lacks of configuration options (eg:resizing/masking the taskbar).

A lot of application that used to work in kde 3.5 does not work anymore (eg: Kopete has a random behaviour when it talks to some Jabber servers).

Some kickass features in applications have been disabled : it is not possible to access directly to a tab in Konsole using a keyboard shortcut, adding custom applet (like a "show desktop button") to the taskbar seems not possible anymore....

Even worse, some settings are not accessible through the control panel anymore, eg: the number of desktops available for application windows can only be configured by right-clicking on the pager taskbar applet, the taskbar options (size, automasking...) seems to be gone, when removing the pager applet, there seems to be no way to enable it back !

After some time, keyboard shortcuts did not work anymore : Alt+TAB just does nothing, Ctrl+Shift+N (new tab in Konsole) split the screen...

So do not even think about installing it

Dell D630 Docking Station and Gentooo Linux

nospam@example.com (philou) — Wed, 21 Nov 2007 15:55:55 +0100

Dell provides a nice docking station where the Dell D630 can be plugged on. But Linux kernel lacks support of this kind of hardware. Even if a "dock" ACPI module is existing in recent 2.6 kernels, it fails to provide ACPI events to acpid : it just have not been implemented in the kernel code :( The quick hack below send some crappy events to the ACPI event bus :

--- ../../../linux-2.6.22-gentoo-r9/drivers/acpi/dock.c 2007-10-31 17:30:44.000000000 +0100

+++ dock.c      2007-11-09 15:06:25.000000000 +0100

@@ -68,6 +68,8 @@



 static struct dock_station *dock_station;



+static struct acpi_device device;

+

 /****************************************************************************

                           Dock Dependent device functions                   

  *****************************************************************************/

@@ -320,7 +322,7 @@

                if (event == ACPI_NOTIFY_EJECT_REQUEST)

                        dock_remove_acpi_device(dd->handle);

                else

-                       dock_create_acpi_device(dd->handle);

+                       device = dock_create_acpi_device(dd->handle);

        }

        mutex_unlock(&ds->hp_lock);

 }

@@ -333,6 +335,7 @@

          changed.

         /

        kobject_uevent(&dev->kobj, KOBJ_CHANGE);

+    acpi_bus_generate_event(device, event, num);

 }



 /**

In Gentoo the event can be matched using the code extracted from my /etc/acpi/default.sh :



if [ $1 = "GDCK" ] ;then

    export XAUTHORITY=/var/run/xauth/`ls /var/run/xauth/`

    export DISPLAY=:0

    if [ $2 = "00000000" ] ; then

        logger "docking ?"

    else

        logger "undocking ?"

    fi

    exit;

fi

Unfortunately, this quick hack fails to detect the first "undock" event if the laptop is docked at boot time...

Xorg, Dual Head and Dell D630

nospam@example.com (philou) — Mon, 19 Nov 2007 10:15:41 +0100

Having the dual head working properly on Linux is a pain in the ass. Especially when your laptop comes with an Intel card.

For an unknown reason using the latest stable intel drivers of the Gentoo linux distribution, getting the DVI output of the docking station working is not possible ; you have to unmask the intel drivers package to get it work. Unfortunately, even with the last drivers, it fails to detects video modes of the DELL 2007WFP flat screen It detects a wrong 1680x1050 video mode (59Hz instead of the required 60Hz). Even worse, this video mode is not selected by default and only detected if X starts while the laptop is docked. To solve this, a ad-hoc xorg.conf file must be setup :



Section "Monitor"

        Identifier      "dvi"

        Option "PreferredMode"  "1680x1050@60"

        Option        "Position" "1280 0"

        Modeline "1680x1050@60" 147.14 1680 1784 1968 2256 1050 1051 1054 1087 -HSync +Vsync

EndSection



Section "Monitor"

        Identifier      "lcd"

        Option "LeftOf"  "dvi"

EndSection



Section "Device"

        Identifier  "Card0"

        Driver      "i810"

        ChipSet     "965GM"

        Card        "i810 965GM"

        Option          "monitor-LVDS" "lcd"

        Option         "monitor-TMDS-1" "dvi"

EndSection

Even with this config specials scripts have to be written in order to get it work (this must be launched after the X startup) :



#!/bin/bash

/usr/bin/xrandr  --output TMDS-1 --mode 1680x1050@60

/usr/bin/xrandr --output TMDS-1 --pos 1280x0

Timemachine & Network Shares

nospam@example.com (philou) — Thu, 15 Nov 2007 18:09:31 +0100

By default, the Leopard TimeMachine is not able to write to Windows network shares. But it comes with an hidden option that allows this to happen. You only have to do this :

defaults write com.apple.systempreferences TMShowUnsupportedNetworkVolumes 1