For example, I want www.foo.com to respond on IP

• 192.168.1.20 from inside the company’s network
• 193.134.215.34 from the outside world

In fact, it turns out that it’s quite easy to implement with the Bind DNS server. A friend pointed me to the usage of “ACLs” and “views” in the Bind configuration. Here is a stripped-out basic example for a named.conf acting like we want:

//We define an ACL for the LAN

acl "lan" { localhost; 192.168.1.0/24; };

//We define a view for requests from the LAN

view "internal" {

  match-clients { lan; };

  zone "foo.com" IN {

    type master;

    allow-query { any; };

    file "foo.com.internal.hosts";

  };

};

//We define a view for external requests

view "external" {

   match-clients { any; };

   zone "foo.com" IN {

     type master;

     allow-query { any; };

     file "foo.com.hosts";

   };

   zone "bar.com" IN {

     type master;

     allow-query { any; };

     file "bar.com.hosts";

   };

};

You first start by defining an ACL (access control list) for your internal network. It’s just an alias and you can include multiple networks in it. The rest of the world already matches a built-in ACL called “any”.

Then you need to define “views” which will match an ACL. As Bind reads your configuration in order and stops on the first match, you need to create a view for your internal network first. In our example, any query coming to *.foo.com from our internal network gets a response from the data in the “foo.com.internal.hosts” file. If you come from the outside world, you will get a response from the data in the “foo.com.hosts” file.

Similarly, if you try to access *.bar.com from inside the network, the server won’t respond as it isn’t responsible for this domain. However, if you try to access *.bar.com from the outside world, you will get an answer from the data in “bar.com.hosts”.

Easy, isn’t it? Of yourse this is only a short example.

Some months ago, I wrote a post about “Configure the KDE Dashboard to behave like in OSX“; the options to configure this have now been moved to System Settings > Desktop > Workspace. Simply select “Show an Independent Widget Set” in the drop-down box and you are done in KDE 4.4.

EDIT: since KDE 4.4, options have been moved!

In OSX, the Dashboard is a “layer” you can superpose to your normal desktop. It’s activated by a button on your keyboard or by moving your mouse to an edge of the screen, so you can access it very quickly. On the Dashboard, you can drop little applications called Widgets, as you can see on the picture below. When you quit the dashboard, all these little widgets are hidden and don’t clutter your normal desktop.

OSX Dashboard I have stolen from Google Image

In Windows Vista/7 you can also add Widgets (called Gadgets), but they simply live on your normal desktop as far as I know. In KDE 4.3 there is a mix of both worlds; there is a Dashboard “layer” similar to what you find in OSX, but all the Widgets are also visible on you normal desktop when you quit the Dashboard view, so it’s cluttered.

Since KDE 4.3 (as far as I know) it’s possible to configure KDE’s Dashboard to behave exactly like in OSX, but the option to configure this is pretty well hidden…let’s see how to activate it in Fedora 12.

First, go to your upper-right corner and click on the little icon to manage your Widgets (it’s called the cashew), select “Zoom Out”…

You will be presented with the following screen, click on “Configure Plasma”…

Now activate the “Use a separate dashboard” option…

To quit the environment, click on the “Zoom In” icon under the desktop picture…

You are done, now you can activate your Dashboard (Ctrl+F12 or a configured screen corner) and throw little Widgets there…they won’t clutter you desktop anymore!

KDE 4.3 Dashboard under Fedora 12, looks quite similar to OSX

]]> http://www.alphatek.info/2009/11/01/fedora-configure-the-kde-dashboard-to-behave-like-in-osx/feed/ 2 http://www.alphatek.info/2009/08/28/skype-2-1-beta-for-linux/ http://www.alphatek.info/2009/08/28/skype-2-1-beta-for-linux/#comments Fri, 28 Aug 2009 10:52:35 +0000 Steven http://www.alphatek.info/?p=452 After quite a while, Skype has released a new version of their client for Linux (2.1 Beta). It FINALLY supports PulseAudio without having to tweak your whole sound system…It’s supported for Fedora 9+, Ubuntu 8+, Debian Lenny and OpenSUSE 11+.

Get the new version here.

Solaris 10 feels particularly old compared to modern Linux distros  like Fedora or enterprise-class Linux distros like CentOS/RHEL, but there are also a couple of very cool technologies included. This blog post is probably the first of a series dedicated to Linux -> Solaris migrations, and how we can learn things from Solaris to improve Linux.

So, the first thing I want to talk about is the updates management.

In Fedora, we have yum/PackageKit to nicely handle the whole process: download the updates and install them. In Solaris 10, there is a jungle of mostly useless applications to download the updates; obtaining them is bit like being in hell, only worse. The most convenient way is to use an application called Patch Check Advanced. But once you have downloaded the updates for your system, you can apply them in a WAY cooler way than in Linux. Let me explain how it works…

First, you have to know that Solaris now comes with a file system called ZFS, which we can’t have in Linux for legal reasons as far as I know. This file system is very similar functionality-wise to Btrfs that we should see in Linux in a couple of months (oddly enough, both “belong” to Oracle now); ZFS supports something called “snapshots”.

Snapshots give you the opportunity to create an exact copy of any file system on the fly in a matter of seconds, without any performance degradation nor disk space use (best case). You can see it as a backup, it’s very similar to Apple’s Time Machine. To handle updates, Solaris 10 uses a set of utilities called “Live Upgrade”, what they do is:

• Create a snapshot (at the file system level, with ZFS) of you whole root partition
• Apply the patches you have downloaded to this snapshot
• Create an entry in GRUB to boot from this “new root” snapshot at the next reboot

The end result is that at the next reboot, you can see if your system still works well with the applied updates.

• It you are happy, you stay with this new root and delete the old one
• If you are unhappy, you reboot to the old root and your system is in its old state

Simply imagine how cool this is for critical servers, or even the end user. You don’t mess at all with the software currently installed, there is no risk as you can roll back and the only downtime you have is the reboot.

With Btrfs coming to Linux, we could absolutely do the same thing, and I’d like to see that. I’m just useless to make that happen in Fedora, but I can at least raise awareness on this with this blog post. I know that this requires a massive paradigm shift for the way we handle updates, we need to move from a “per application update” to a “complete OS state update”. Instead of selecting a specific kernel to boot in GRUB, you would select a system state.

On a side note, OpenSolaris’ package manager (similar to PackageKit) does exactly that.

Here is a complete Live Upgrade sequence I did on a Solaris 10 box

[root@sol10 /]$ lucreate -n s10Aug2209 (We create a / ZFS snapshot called s10Aug2209)
Checking GRUB menu…
Analyzing system configuration.
No name for current boot environment.
INFORMATION: The current boot environment is not named – assigning name <root-dataset>.
Current boot environment is named <root-dataset>.
Creating initial configuration for primary boot environment <root-dataset>.
The device </dev/dsk/c0d0s0> is not a root device for any boot environment; cannot get BE ID.
PBE configuration successful: PBE name <root-dataset> PBE Boot Device </dev/dsk/c0d0s0>.
Comparing source boot environment <root-dataset> file systems with the
file system(s) you specified for the new boot environment. Determining
which file systems should be in the new boot environment.
Updating boot environment description database on all BEs.
Updating system configuration files.
Creating configuration for boot environment <s10Aug2209>.
Source boot environment is <root-dataset>.
Creating boot environment <s10Aug2209>.
Cloning file systems from boot environment <root-dataset> to create boot environment <s10Aug2209>.
Creating snapshot for <rpool/ROOT/root-dataset> on <rpool/ROOT/root-dataset@s10Aug2209>.
Creating clone for <rpool/ROOT/root-dataset@s10Aug2209> on <rpool/ROOT/s10Aug2209>.
Setting canmount=noauto for </> in zone <global> on <rpool/ROOT/s10Aug2209>.
Creating snapshot for <rpool/ROOT/root-dataset/var> on <rpool/ROOT/root-dataset/var@s10Aug2209>.
Creating clone for <rpool/ROOT/root-dataset/var@s10Aug2209> on <rpool/ROOT/s10Aug2209/var>.
Setting canmount=noauto for </var> in zone <global> on <rpool/ROOT/s10Aug2209/var>.
Saving existing file </boot/grub/menu.lst> in top level dataset for BE <s10Aug2209> as <mount-point>//boot/grub/menu.lst.prev.
File </boot/grub/menu.lst> propagation successful
Copied GRUB menu from PBE to ABE
No entry for BE <s10Aug2209> in GRUB menu
Population of boot environment <s10Aug2209> successful.
Creation of boot environment <s10Aug2209> successful.

[root@sol10 /]$ zfs list (we look at the ZFS partition list, we can see that we have snapshots)
NAME                                     USED  AVAIL  REFER  MOUNTPOINT
rpool                                   10.4G   446G  38.5K  /rpool
rpool/ROOT                              1020M   446G    18K  legacy
rpool/ROOT/root-dataset                 1020M   446G   804M  /
rpool/ROOT/root-dataset@s10Aug2209      64.5K      -   804M  -
rpool/ROOT/root-dataset/var              216M   446G   216M  /var
rpool/ROOT/root-dataset/var@s10Aug2209    98K      -   216M  -
rpool/ROOT/s10Aug2209                     92K   446G   804M  /
rpool/ROOT/s10Aug2209/var                   0   446G   216M  /var
rpool/dump                              4.88G   446G  4.88G  -
rpool/export                              48K   446G    19K  /export
rpool/export/home                         29K   446G    29K  /export/home
rpool/swap                                 4G   450G    16K  -

Download the patches in /var/tmp/10_Recommended with Patch Check Advanced.

[root@sol10 /]$ luupgrade -n s10Aug2209 -s /var/tmp/10_Recommended -t `cat patch_order` (we apply the patches to the snapshot)

[root@sol10 /]$ luactivate s10Aug2209 (we activate the updated snapshot for the next boot)
Generating boot-sign, partition and slice information for PBE <root-dataset>
Saving existing file </etc/bootsign> in top level dataset for BE <root-dataset> as <mount-point>//etc/bootsign.prev.
A Live Upgrade Sync operation will be performed on startup of boot environment <s10Aug2209>.

Generating boot-sign for ABE <s10Aug2209>
Saving existing file </etc/bootsign> in top level dataset for BE <s10Aug2209> as <mount-point>//etc/bootsign.prev.
Generating partition and slice information for ABE <s10Aug2209>
Copied boot menu from top level dataset.
Generating multiboot menu entries for PBE.
Generating multiboot menu entries for ABE.
Disabling splashimage
Re-enabling splashimage
No more bootadm entries. Deletion of bootadm entries is complete.
GRUB menu default setting is unaffected
Done eliding bootadm entries

Modifying boot archive service
Propagating findroot GRUB for menu conversion.
File </etc/lu/installgrub.findroot> propagation successful
File </etc/lu/stage1.findroot> propagation successful
File </etc/lu/stage2.findroot> propagation successful
File </etc/lu/GRUB_capability> propagation successful
Deleting stale GRUB loader from all BEs.
File </etc/lu/installgrub.latest> deletion successful
File </etc/lu/stage1.latest> deletion successful
File </etc/lu/stage2.latest> deletion successful
Activation of boot environment <s10Aug2209> successful.

[root@sol10 /]$ init 6 (we reboot)
propagating updated GRUB menu
Saving existing file </boot/grub/menu.lst> in top level dataset for BE <s10Aug2209> as <mount-point>//boot/grub/menu.lst.prev.
File </boot/grub/menu.lst> propagation successful
File </etc/lu/GRUB_backup_menu> propagation successful
File </etc/lu/menu.cksum> propagation successful
File </sbin/bootadm> propagation successful

[root@sol10 /]$ lustatus (we check the boot environments we have)
Boot Environment           Is       Active Active    Can    Copy
Name                       Complete Now    On Reboot Delete Status
————————– ——– —— ——— —— ———-
root-dataset               yes      no     no        yes    -
s10Aug2209                 yes      yes    yes       no     -

[root@sol10 /]$ ludelete root-dataset (we delete the old root)
System has findroot enabled GRUB
Checking if last BE on any disk…
BE <root-dataset> is not the last BE on any disk.
Updating GRUB menu default setting
Changing GRUB menu default setting to <0>
Saving existing file </boot/grub/menu.lst> in top level dataset for BE <s10Aug2209> as <mount-point>//boot/grub/menu.lst.prev.
File </etc/lu/GRUB_backup_menu> propagation successful
Successfully deleted entry from GRUB menu
Determining the devices to be marked free.
Updating boot environment configuration database.
Updating boot environment description database on all BEs.
Updating all boot environment configuration databases.
Boot environment <root-dataset> deleted.

Grab it on the Adobe Labs page and follow my instructions on this blogpost to install it. these instructions are valid for Fedora 10, 11 and basically any 64-Bit Linux OS.

So it was the perfect opportunity to look for another application…it turns out that Banshee is now a really great and mature product (if you don’t mind installing the Mono stack). It supports smart playlists, automatic cover art download, dynamic music library update, videos using the gstreamer back-end, online radios, podcasts AND an automatic synchronization to my Nokia phone! Wooohooo…the only drawback in comparison to Rhythmbox is that it doesn’t act as a DAAP music server.

When you want to install Fedora on one of these machines, you have 2 choices:

• Use Bootcamp to create an OS X/Fedora dual boot system.
• Install Fedora natively as the only OS.

If you use the second option (which is what I do), you will soon be faced with an annoying problem: the Fedora you just installed via the graphical interface probably won’t boot. Your Mac will display a message saying something like “No boot device found, please insert a bootable media”. Duh.

The problem is that Intel Macs are using EFI instead of a standard BIOS, and the hard drive is pre-formatted with a “gpt” partition table instead of the standard “msdos” partition table. To install a working stand-alone Fedora on such a machine, you have to do ONE thing at the right moment:

• When you launch the Anaconda installer from the DVD, hit ctrl+alt+F2 to switch to a console.
• Run “parted” to modify your hard drive structure.
• In parted, run “mklabel msdos” to switch from gpt to the more standard msdos disk label. This will destroy all your data, so be careful.
• Switch back to the installer with ctrl+alt+F6.
• Install Fedora 11 like you do it usually.

That’s it…it can be quite frustrating if you don’t think about it.

They clearly don’t do this for profit, so if you want to support gaming on Linux, go ahead. It works perfectly on Fedora 11 x86-64 after some yum installs A more complete description can be read on http://linuxlock.blogspot.com/2009/07/are-you-afraid-you-will-be.html

If you look at the bottom of the page, you’ll see this:

So, if it’s not a typo, we could have a pretty good surprise soon