All posts by flo

Hetzner Root Server Networking Configuration…

I’ve been setting up a new server at hetzner.de.
I ran into problems when configuring the network. The server is running Debian (wheezy).

hetzner network info
note the last line: “The additional route to the gateway is now no longer necessary.” not only that: it will not work.

The basic configuration looked like this:

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## /etc/network/interfaces example Hetzner root server
# Loopback-Adapter
auto lo
iface lo inet loopback
#
# LAN interface
auto eth0
iface eth0 inet static
# Main IP address of the server
address 192.168.0.250
# Netmask 255.255.255.255 (/32) independent from the
# real subnet size (e.g. /27)
netmask 255.255.255.255
# explicit host route to the gateway
gateway 192.168.0.1
pointopoint 192.168.0.1

This should work, as mentioned in the Hetzner DokuWiki.

I added DNS servers at the end (use your DNS servers here or pick an open DNS server)

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dns-nameservers X.X.X.X Y.Y.Y.Y

at the end since I’ve resolvconf installed.
eth0 did not come up correctly.

When trying ‘ifdown eth0; ifup eth0’ I kept getting:

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ifdown: interface eth0 not configured
RTNETLINK answers: File exists
Failed to bring up eth0.

This error would show up at boot time or when trying to start eth0 by hand.
The setup would look fine otherwise, IP was correct network seemed to work, but the DNS-servers were not added correctly. Weird!

‘ifdown –force eth0; ifup eth0’ worked. Server went off for a second but came back. with DNS-servers setup correctly. Interesting!

I started to comment out lines from /etc/network/interfaces.
Et voilá!

It turns out: It is deadly to try to configure ‘gateway’ in /etc/network/interfaces!

Finally I used this:

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## /etc/network/interfaces working Hetzner root server
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address 192.168.0.250
netmask 255.255.255.255
# next line optional
network 192.168.0.0
## never EVER use the next line! you have been warned!
## gateway 192.168.0.1
pointopoint 192.168.0.1
dns-nameservers X.X.X.X Y.Y.Y.Y

I hope this post will save others some time to fix this issue with their setup.

Lego Lamp

More than a year ago I came across a designer lego lamp. I really liked the idea but the price tag was a little hefty. Back then the lamp cost $800 and now it is at $995. But to be honest there is no designer product like this lego lamp that really says “do it yourself” like that!

So I built one myself. I designed the basic form with Lego Digital Designer. The plan can be found here [1]. The base of the lamp uses about 800 pieces. The final build varies from the my first plan, especially in the base where I first planned to hide the foot of the old Ikea lamp. I finally just used the lamps main rod and electrical wire. The arrangement of the bricks varies to give the lamp more structural integrity and was improvised.

The parts were ordered from three different shops on BrickLink. They offered the green I wanted for the lamp at a fraction of the price of the original Lego™ store. The total price for all parts was about 60€. The lamp I had laying around was ‘free’ and the new lamp shade was about 30€. Total of about 100€ – well below the price point of the original.

[1] 2014-11-22, 18:30:

I was asked by the designer Sean Kenney, to remove the LDD plans for the lamp. He argued that the plans would hinder his ability to sell these lamps online.

Although I do not agree with Sean’s argument, that his sales might be influenced by a simple Lego™ scetch for a similar lamp, I’ve respect for the work that went into the lamps Sean designed and did take the plans down for now.

Adding SSL to transmission’s web interface…

If you’re using transmission’s web interface to manage your torrent downloads, and you are doing this remotely (from outside your LAN), you might want to add some privacy.

As previously posted there are ways to use magnet links with transmission’s web interface. This webinterface works well when you are on your local network aka LAN and don’t have to fear prying eyes.
The moment you’re using the transdroid android app or your laptop in a coffee shop the commands and responses of your transmission daemon at home can be read by anyone.

Luckily the transdroid android app offers an SSL option. All you have to do is configure a proxy on your transmission daemon machine.

Here is how:
Install nginx (a lightweight http/https server):

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apt-get install nginx

Continue reading Adding SSL to transmission’s web interface…

Bitcoin Paper Wallet Treasure Chest…

The Bitcoin Paper Wallet Treasure Chest
The Bitcoin Paper Wallet Treasure Chest
One of the challenges with bitcoin is to store them securely. There have been several well known incidents where Bitcoins have been stolen. It is no mystery. Bitcoin IS money! It’s the same with Euros or Dollars, when you have it lying around it will eventually be missing.

There is a twist with bitcoin to regular money. With Bitcoin one single piece of information is enough for the thief to steal your Bitcoins: Your private key. With Bitcoin it’s about keeping this piece of information secret.

Continue reading Bitcoin Paper Wallet Treasure Chest…

Open Street Map RL Wallpaper…

The final result
The final result

We wanted to paint one wall in our vestibule to add a little more color to the room. As we could not settle on a specific color, I thought of wallpaper. And is there any better theme than OpenStreetMap Data¹?

 
The theme was settled. It had to be a map, but which tiles? I thought of the beautiful pencil drawn MapBox tiles I saw some time ago:

OpenStreetMap Pencil Tiles by MapBox
OpenStreetMap Pencil Tiles by MapBox

We wanted some redish color so I had to convert the image with ImageMagick:

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$ ./colorize.sh 25 file_in.png file_out.png
$ cat colorize.sh
#!/bin/bash
# I found this script in the imagemagick formus:
# http://www.imagemagick.org/discourse-server/viewtopic.php?t=17460#p91820
# It does about the same as gimp with the colorize option.
test -z $1 && exit -1

hue=$1
sat=50
light=0
hue=`convert xc: -format "%[fx:100*$hue/360]" info:`
sat=`convert xc: -format "%[fx:2*$sat]" info:`
test=`convert xc: -format "%[fx:$light<0?0:1]" info:`
light=`convert xc: -format "%[fx:abs($light)]" info:`
if [ $test -eq 0 ]; then
fillcolor="black"
else
fillcolor="white"
fi

convert \
$2 -set colorspace RGB -colorspace gray -set colorspace sRGB \
-fill "hsl($hue%,100%,50%)" -tint 40% \
-modulate 100,$sat,100 \
-fill $fillcolor -colorize $light% $3

the result is something like this:
Continue reading Open Street Map RL Wallpaper…

Big Bang Theory Relationship Diagram Update…

Two years ago I did a relationship diagram based on data collected from The Big Bang Theory TV-Series. Meisterluk updated his data for the seasons 5 and 6.
Obviously I had to update my diagram, which I finally had time to do. Here it is:

Big Bang Theory Relationship Diagram

It is only based on the data regarding dating and sex. The little mistakes I found in Meisterluk’s data i corrected again and am mirroring the corrected data here.

What did I change for the new version 1.4, since the last version 1.3 from 2011? I moved the names into the circles to keep it more compact. I changed the position of the timeline and moved some characters around for readability.
The basic concept is the same as in v 1.3. Characters that share the same length and color line on the radial timeline in the same radial distance have a relationship (date/sex). That’s it.
One can clearly see that Leonard and Penny have an on-and-off relationship. Which they finally pick up again in season 5. Sheldon and Amy, and Howard and Bernadette have the two stable relationships in the group. Their relationships go on for almost 3 seasons now.
Raj seems almost asexual if one compares his timeline. He has only one sexual encounter per season. I did not count the ‘dating’ Raj did with Siri as it is a computer voice. At the end of season 6 Raj finally picks up a relationship with Lucy. Let’s see where this ends in season 7.