Sonntag, 2. September 2012

Mac OS X Wake On LAN (WOL)

Manny Mac user have problems getting WOL to work properly.
You often read, that WOL is only possible if a „Magic Packet“ is sent via LAN. Apparently this wont work via WLAN.
However some of us would like to wake up our Mac connected via WLAN with any Network access: A web request or a VNC connection. Not just by using special software like (the very good iPhone App) iNET.

Actually i didn‘t even manage to wake up my Mac Min with iNET, after it had went to sleep (slow flashing LED). When my Mac was sleeping iNET didn‘t even find it with a network scan.

Well, there is a solution to this, with a small drawback. I‘l get back to the drawback later.

If you have a look in the system information, you will find astonishing parameters, that you can change if you know where to find them.

Open the system information e.g. by clicking on the Apple in the upper left corner of your monitor. Then click „About this Mac“. Go on by clicking on „further information“ and then „System profiler.“
In the left pane under „Harwdare“, click on „Power“. On the right pane you find a parameter  „PrioritizeNetworkReachibilityOverSleep“, which is set to 0 (zero). You also find a parameter which tell in how many minutes the hard disk will go to sleep.

You wont find this settings on the GUI (System Preferences). You find them in the file
„/Library/Preferences/SystemConfiguration/“ which you can edit with a text editor. You do have to have root rights to do that however.
A very convenient editor for this type of work it TextWrangler, as it prompts you to „unlock“ the file, as you go.

I use my Mac Mini as a test web server, so i set the „PrioritizeNetworkReachibilityOverSleep“ as well as the „Disk Sleep Timer“ to 1.

After editing this file, you have to enter the system preferences clicking on „energy saver“ in the „Hardware“ section, checking „wake for network access“.

That‘s it!
Now my Mac shuts down the monitor and the hard dis after 1 minute and i can wake it up with any network access. In this type of sleep mode the LED is not slow flashing any more. Its solid. The Mac still appears when i do a network scan (with iNET).

The drawback is, that the cooling fan doesn‘t go to sleep.

When making a web request e.g. the Mac Mini fires up the hard disk at no time and everything is up and running. Note: This works over (W)LAN as well as internet using a port forwarding.

This is my configuration: internet -> router (FritzBox with port forwarding) -> WLAN -> Mac mini.

Have fun!

Montag, 25. Juni 2012

Ruby on Rails development in the Browser

The browser is developing more an more to an os, ide,...
This idea e.g. is great. Rails development completely in the browser:

Donnerstag, 24. Mai 2012

Start free for - a refrigeration management system

At the first of June 2012 we start operating, a management system for refrigeration units, as well as general actions taken on user defined objects.

For the refrigeration business, offers a complete management of master data, refrigeration units and used refrigerants. With the built in analyses  you can quick get an overview of the trend on used refrigerants e.g.
As all the data are optional, you are - if wanted - able to manage your units quite anonymous. is a multi lingual system. For the moment, the languages english, german, french, italian, polish, spanish and swedish are native supported.
We intend to implement approximately 30 languages.

State of the art technology has made it possible to keep the price very low. As we won‘t calculate any fee for the sole management, there is no reason more to use excel tables.

In a forthcoming extension of the system, we will integrate a document management system, where you can store you units documentation.

Startschuss für - ein Verwaltungssystem für Kälteanlagen

An dem 01.06.2012 geben wir den Startschuss für, ein Verwaltungssystem für sowohl Kälteanlagen als auch allgemeine Tätigkeiten an frei zu definierenden Objekten.

Für die Kältebranche bietet eine vollständige Verwaltung von Stammdaten, Anlagen und eingesetztes Kältemittel. Mit Hilfe der Auswertungen kann schnell der Trend z.B. in Sachen Leckagerate ermittelt werden.
Da alle Daten optional sind, kann - falls erwünscht - die Anlagen relativ „Anonym“ verwaltet werden. ist ein mehrsprachiges System. Zunächst werden die Sprachen English, Deutsch, Französisch, Italienisch, Polnisch, Spanisch und Schwedisch unterstützt. Das Ziel liegt bei Ca. 30 Sprachen.

Neuste Technik hat uns erlaubt, den Preis sehr niedrig zu halten. Da für de Verwaltung alleine keine Gebühren erhoben werden, gibt es jetzt kein Grund mehr Excel-Tabellen mehr zu nutzen.

In eine kommende Ausbaustufen, ist ein integriertes Dokument-Management-System geplant. In dem Archiv, kann z.B. Schaltpläne und ähnliches elektronisch hinterlegt werden.

Start för - ett förvaltningssystem för kylanläggningar

Den förta juni 2012 startar vi, ett förvaltningssystem för kylanläggningar så väl som generella aktiviteter på fri definierbara objekter.

För kylbranschen erbjuder en fullständig förvaltning av stamdata, anläggningar och använt kylmedel. Med hjälp av utvärderingarna kan man snabbt utläsa trenden gällande tex. graden av kylmedel läckage.
Eftersom alla data är valfria, kan - om önskvärt - anläggningarna förvaltas relativ „anonymt“. är ett mångspråkigt system. Till att börja med, är språken engelska, tyska, franska, italienska, polska, spanska och svenska omsatta. Målet ligger vid Ca. 30 språk.

Nyaste teknik, har gjort det möjligt, att hålla priset väldigt lågt. Eftersom vi inte tar några avgifter för själva förvaltningen, så finns det inga skäl längre att använde excel tabeller.

I en kommande utbyggnad av systemet, är ett dokument förvaltnings-system planerat. I det arkivet, kan man tex. lagra dokumentationen till anläggningarna.

Mittwoch, 9. Mai 2012

Setting up SSL on Heroku

Recently i bought an Thawte SSL certificate for my Heroku application, and i thought it would be useful for you if i wrote down my „how to do“ cook book to get it up and running.
By the way. I'm a Mac user, so for Windows there could be slightly differences...

Please note, that is a placeholder for your domain.

1. Generate a Private Key

-> openssl md5 * > rand.dat
-> openssl genrsa -rand rand.dat -des 2048 >
Now you are asked to enter a pass phrase.
Please remember the phrase well, you will need it later!

2. Create a CSR

To be able to order a certificate, you have to supply some information. That bundle of information is called an Certificate Signing Request (CSR).

You generate it using your recently generated key, with the command below.

-> openssl req -new -key -out

Now you are asked to enter your pass phrase, entered in step 1 above.
Further more, you have to answer the questions asked:
- Two letter country code: DE (for Germany e.g.)
- State or Province: Bavaria (e.g.)
- Locality Name (e.g. city): Gerbrunn
- Organization Name (e.g. company): Company Ltd (e.g.)
- Organizational Unit Name (e.g. section): CEO
- Common Name (the domain name used with the SSL cert.):
- Email Address:

'extra' attributes to be sent with the certificate request
- A challenge password: (just return to leave empty)
- An optional company name: (just return to leave empty)

Please note, that according to what certificate you want to order, the data entered here must be the same as in the whois record for the domain. In my case, ordering the certificate "Limitbreaker" provided by that wasn't necessary

3. Order a certificate

Copy the content of the to your clipboard, and paste it into the order form.
For mac users. This command transfers the content of the file into the clipboard:
-> pbcopy <

(Hint: "pbpaste > file.txt" is the opposit command ;-)

You can check you CSR here:

When you have gotten the certificate (my mail or download), save it in the file

The certificate that i acquired by Thawte also has an intermediate certificate, that has to be installed in order for the certificate to function properly.
Save that in the file:

To keep older browser and mobile devices support, i ALSO had to install the Thawte Cross Root CA Certificate (as additional intermediate certificate).
 Save that in the file

Now use a simple and pure text editor to combine all three certificates in one file.
The content of the new file should look like this:

... content of the file ...
... content of the file ...
... content of the file ...

Save this in the file

4. Remove passphrase from key

Later on we need the generated key without the pass phrase, so we have to remove it here:

-> openssl rsa -in -out

Now you have to enter the pass phrase again, and you get the answer: "writing RSA key"

5. Add the Heroku SSL Addon "SSL"

What Heroku SSL service you choose, depends on what you need and on what stack your app is runnig. My app is unfortunately running on the cedar stack, so i have to choose the Endpoint SSL.
(I dont understand, why that cost $20,- / month.)

You add the ssl addon with this command, in the root directory of your project:

-> heroku addons:add ssl:endpoint

6. Add the certificate to your app on Heroku

Copy the files and to your project root directory and enter the command:

-> heroku ssl:add

Now, as the ssl:endpoint has gon "main stream" on the cedar stack, you add the certificate using this command:
-> heroku certs:add  

7. Check

This Heroku command lists some usefull commands:

-> heroku ssl --help

To get the ssl info for your application, just type this command in the root directory of your project:

-> heroku ssl

8. Self signed Certificate

If you have any problems, you could check if everything else is ok, by creating a self signed certificate.
There exist a Heroku docu on that:

Here are the steps taken from the Heroku doku:
Generate Key:
-> genrsa -des3 -out site.key 2048

Copy key:
-> mv site.key site.orig.key

Remove pass phrase from key:
-> openssl rsa -in site.orig.key -out site.key

Create CSR:
-> openssl req -new -key site.key -out site.csr

Create Certificate:
-> openssl x509 -req -days 365 -in site.csr -signkey site.key -out final.crt

Install on Heroku:
-> cd [root directory of your project]
-> heroku ssl:add final.crt site.key

9. Further reading

Regarding file name extensions:

Have fun!
Comments and hints are welcome.

Donnerstag, 23. Februar 2012

Please login to use the PayPal Sandbox features

Have you ever got this error message while playing around with the PayPal Sandbox?
Trying over and over again, with your test buyer account...
Well, the solution is surprisingly simple.

When you sign up for the PayPal sandbox, you first get a master user id. After login on with the master id you can create the test buyer and seller accounts.

When making a test purchase with the test buyer account, you must be logged on with the master account id - on a second tab in the same browser!

That‘s all!

Have fun!

Mittwoch, 4. Januar 2012

Suche Rails-Entwickler

Für ein sehr interessantes Projekt, suche ich einen Rails-Entwickler, oder Jemandem, der sich einarbeiten will. Voraussetzung wäre in dem Fall Vorauskenntnisse in ein MVC-Framework wie z.B. Symfony.

Ich biete auch eine Unternehmensbeteiligung für diejenigen, die eine langfristige, selbständige Tätigkeit suchen.
Bitte melden!