HTTP/1.1 200 OK

HTTP/1.1 200 OK

If you tried to access this site in the past months, you were probably greeted with the above message. After noticing suspicious behaviour on the server providing the site in fall 2014, I nailed the issues down to the WordPress installation (probably some plugin gone bad) and decided to take the site offline to sort out these issues. Given the fact that I didn’t find the time to do that until now the unavailability was rather permorary ;)

However, this blog is up and running again – stuffed with even older content than ever before, but as some things may still be useful I kept most posts as they were. I’m curious how Google will catch up with the site being online again as it seems they kicked me out of the index completely.

Fun fact: albeit being offline for roughly 6 months, the site still has an average uptime of > 70%.

Stream a file with StreamedResponse in Symfony

Wow, long time no blog post, huh? Here’s a quick tip how to stream a (presumably large) file to your client with Symfony without the need to load the file into memory.

$file   = '/tmp/a-large-file.jpg';
$format = pathinfo($file, PATHINFO_EXTENSION);

return new Symfony\Component\HttpFoundation\StreamedResponse(
    function () use ($file) {
    }, 200, array('Content-Type' => 'image/' . $format)


HTC Desire Windows 7 64-Bit adb driver

I just had some troubles to get adb to work together with my HTC Desire on Windows 7 64-Bit. When attaching the phone in USB debugging mode, it showed up as “My HTC” device, but adb couldn’t connect to it.

First of all, you need to install HTC Sync and the included USB drivers to get your device working normally with your computer (e.g. showing up as disk drive). Then install the Android SDK and the USB drivers package (from SDK manager) and add the following lines to the file extras\google\usb_driver\android_winusb.inf inside the [Google.NTamd64] section (before [USB_Install] around line 65):

;HTC Desire
%CompositeAdbInterface%     = USB_Install, USBVID_0BB4&PID_0C87&MI_01

Use this driver for the “My HTC” device. It should install, show up as “Android Composite ADB Interface” afterwards and work with adb (do an adb devices to check).


Shorewall logcheck pattern

A logcheck ignore pattern to filter out shorewall REJECT and DROP entries (net is defined as eth0). /etc/logwatch/ignore.d.server/shorewall:

^w{3} [ :[:digit:]]{11} [._[:alnum:]-]+ kernel:( [ *[[:digit:]]+.[[:digit:]]+])? Shorewall:net2([a-z0-9]*):(REJECT|DROP)

Test if the regex works for your config:

sed -e 's/[[:space:]]*$//' /var/log/syslog | egrep '^w{3} [ :[:digit:]]{11} [._[:alnum:]-]+ kernel:( [ *[[:digit:]]+.[[:digit:]]+])? Shorewall:net2([a-z0-9]*):(REJECT|DROP)'

Install Windows Server 2008 on KVM/VirtIO

An example how to install a Windows Server 2008 guest on KVM with VirtIO (on a LVM volume in the example). Besides the installation medium you need the VirtIO drivers for windows in order to be able to access the disk device. You can get signed binary drivers here. Then set up a Windows VM with a command like this:

$ virt-install --connect qemu:///system --arch=x86_64 -n win2k8 -r 1024 --vcpus=2 
--disk pool=vmstore,size=50,bus=virtio,cache=none -c /path/to/win2k8.iso --vnc 
--noautoconsole --os-type windows --os-variant win2k8 --network network=subnet,model=e1000 
--disk path=/path/to/virtio-win-1.1.16.iso,device=cdrom,perms=ro

When the guest is running, shut it down and edit the os section of the XML file to look like this (otherwise Windows setup won’t let you install on the disk):

$ virsh destroy win2k8
$ virsh edit win2k8

Change the XML as follows:

  <boot dev='cdrom'/>
  <boot dev='hd'/>

Start the guest again:

$ virsh start win2k8

Connect to the VNC console and start the installation process. When you reach the form to select a disk device you won’t see any devices available. Click on “Load drivers” at the bottom left and load the drivers from E:\viostor\wlh{amd64|x86}. After the drivers are installed, you’ll see a disk device and can continue with the installation.


Fetchmail/Sieve on ISPMail setup – update

Quite some time ago I wrote a tutorial on how to integrate fetchmail and sieve into virtual mail with Postfix and Dovecot. As time passes and things change, here’s an update:

  1. I don’t use the sieve part anymore. Instead, I use the ManageSieve server provided by Dovecot. It integrates with Dovecot’s authentication system and you can use all kinds of clients supporting the managesieve protocol, e.g. Thunderbird or Roundcube.
  2. The ISPMail database structure changed since I wrote that tutorial which still relied on the DB structure for the Debian Etch structure. I updated the script to reflect both environments (take a look at the config file). However, it does not rely on any DB views anymore.
  3. The script (only the Fetchmail part) is now hosted on GitHub as I rarely use SVN anymore and the SVN may go offline in the near future. If anybody is interested in the Sieve part, just drop me a line.

Restore MySQL databases from raw *.frm files

I recently needed to restore data from a MySQL server where the host machine crashed and where I unfortunately didn’t have a proper dump backup – all I had was a backup of the MySQL data directory (/var/lib/mysql in case of Debian). After some googling I didn’t find a simple solution how to restore databases out of this backup. The solution which worked in the end was the following: I installed a fresh MySQL server in a virtual machine and replaced its data directory with the one from my backup (I had exactly the same MySQL versions on both machines). This allowed me to access the databases and create proper dumps which I could import in my real server later.

So, step one: in a virtual machine/spare server/local pc/whatever install a MySQL server and replace its data directory:

$ aptitude install mysql-server
$ /etc/init.d/mysql stop
$ mv /var/lib/mysql /var/lib/mysql.orig
$ cp -pr /tmp/backup/mysql /var/lib
$ chown -R mysql.mysql /var/lib/mysql

I also checked that file permissions match the normal permissions on Debian MySQL installations. Should be like this:

root@host:/var/lib/mysql# ls -al
drwx------  5 mysql mysql     4096 Mar  1 18:20 .
drwxr-xr-x 33 root  root      4096 Mar  1 18:20 ..
-rw-r--r--  1 root  root         0 Mar  1 18:07 debian-5.1.flag
-rw-rw----  1 mysql mysql 27262976 Mar  1 18:21 ibdata1
-rw-rw----  1 mysql mysql  5242880 Mar  1 18:21 ib_logfile0
-rw-rw----  1 mysql mysql  5242880 Mar  1 18:21 ib_logfile1
drwx------  2 mysql mysql     4096 Mar  1 18:20 database1
drwx------  2 mysql mysql     4096 Mar  1 18:21 database2
drwx------  2 mysql root      4096 Mar  1 18:08 mysql
-rw-------  1 root  root         6 Mar  1 18:08 mysql_upgrade_info
root@host:/var/lib/mysql# ls -al database1
drwx------ 2 mysql mysql 4096 Mar  1 18:20 .
drwx------ 5 mysql mysql 4096 Mar  1 18:20 ..
-rw-rw---- 1 mysql mysql   65 Mar  1 18:20 db.opt
-rw-rw---- 1 mysql mysql 8668 Mar  1 18:20 table1.frm
-rw-rw---- 1 mysql mysql  879 Mar  1 18:20 table2.frm
-rw-rw---- 1 mysql mysql 1520 Mar  1 18:20 table3.frm

Now you can try to start the server and look if your databases are readable:

$ /etc/init.d/mysql start
$ mysql -uroot -p -e "show databases;"
Enter password:
| Database           |
| information_schema |
| database1          |
| database1          |
| mysql              |

If this works, simply dump your needed databases with mysqldump, transfer them to your server and import them normally.

$ mysqldump -uroot -p database1 > /tmp/database1.sql
$ scp /tmp/database1.sql user@server:/tmp

On the server:

$ mysql -uroot -p -e "create database database1;"
$ mysql -uroot -p database1 < /tmp/database1.sql

And don’t forget to restore the temporary MySQL server to normal operation in case you need it later.

$ /etc/init.d/mysql stop
$ rm -rf /var/lib/mysql
$ mv /var/lib/mysql.orig /var/lib/mysql
$ /etc/init.d/mysql start

Use a LVM volume group with libvirt

A short howto how to use a LVM volume group with libvirt on Debian Squeeze (used for KVM VMs in my case). I assume your VG already exists and is dedicated for libvirt usage. In my case it’s /dev/vg1.

First of all, create the XML definition for the storage pool in /etc/libvirt/storage/vg1.xml. This is the minimal configuration needed, libvirt will extend it with things like UUID when you define it.

<pool type='logical'>

Now you can tell libvirt about the new storage pool and let it start automatically.

$ virsh pool-define /etc/libvirt/storage/vg1.xml
$ virsh pool-start vg1
$ virsh pool-autostart vg1
$ virsh pool-info vg1

Creating virtual machines inside that storage pool is easy as pie:

$ virt-install -d --hvm --vnc --name=vm01 
    --ram 512 --disk pool=vg1,size=10,bus=virtio,cache=none 
    --network network=default,model=virtio 
    --os-type=linux --os-variant=debiansqueeze