Ubuntu on nidomiro

More secure deployments via ssh

Fri, 21 Aug 2020 12:00:00 +0000

If we deploy an application automatically we have to grant the CI (Continuous Integration) access to the server. Common practice is to do that via a GitLab Runner or an ssh account on the server.

Personally I would not recommend using a GitLab Runner for deployments, because you have to maintain it. Another potential issue is, that you normally register runners for your whole GitLab instance or groups. That results in a scenario in which everyone can use that runner and accidentally (or not) destroy, for example, your production server. To avoid that you have to register the GitLab Runner in the Project it belongs to only. But even then your production server can be misused as a build worker and therefore create performance issues.

Install cmake 3.11.1 on Ubuntu

Tue, 17 Apr 2018 20:00:00 +0200

Sometimes you just want a newer version than ubuntu ships. This code will update cmake to version 3.11.1 or any other version you want.

Automatic VirtualBox module signing for UEFI

Tue, 17 Apr 2018 19:49:00 +0200

These steps are for all those people who hate to sign the Virtualbox modules every time and don’t want to disable UEFI.

Ubuntu: automatic password for second encrypted disk

Thu, 15 Dec 2016 21:23:00 +0200

I just encountered the problem that I have to type two passwords at startup, for two encrypted disks. My first disk is encrypted through the Ubuntu installer. After some searching I found the perfect solution for that task. In german, it’s called “Schlüsselableitung”, in English derived keys. But perfect solutions often have a big issue why they don’t work, like here. I’m using Ubuntu 16.04 which uses ´systemd´, and that has problems with derived keys. So I found the second most perfect solution for me, using a key-file. Some people argue that this is a security issue, but the derived key is also obtainable with root rights, just like a key-file. And by the way, your private keys of your certificates are also stored on that disks and nearly nobody complains about that.

Why I love the Qt framework

Sat, 15 Oct 2016 21:31:00 +0200

Everyone that knows me, knows that I love the Qt framework. Before I started programming in C++, Java was my primary programming language. I love the generics (yes, some of you will hate me for that opinion right now) and reflection. During my Java-time I used them very often to increase reusability. But while studying we had to learn C++ and I hated it in the beginning. It felt so old and so stiff compared to Java. But in one lecture we used Qt, and it was even more terrible - in the beginning. Signals, Slots, QWidgets, … it was too much. After working with it for some time it felt better. What I really liked about Qt from the beginning was the Qt Designer. For the first time I was able to have fancy ui’s in C++ and don’t have to bother with a C api. In Java, I had a graphical editor for Swing. So creating ui’s was now as easy as in Java, maybe a bit easier. But the results with Qt are much better and fancier. After some reading and experimentation I began to understand how Signals and Slots work. From now on I really liked Qt. It was awesome. It was so easy to accomplish tasks, and it still is. If you build an application with an ui and some heavy stuff to calculate, or simply said two threads to communicate, it is very easy with Qt. Just use Signals and Slots to communicate between the threads and the Qt framework will deal with all the synchronization stuff (If you use them properly). You can also use Signals and Slots to loosely couple objects. The sender-object that emitted the Signal, does not know where it is going and the receiver-object does not know where it came from. So you easily exchange components, just like with dependency injection. If I write an application and use the C++ standard library and Qt, I can be sure that it will compile and run on all the mayor platforms. A few months ago I switched from Windows to Linux. The reason why I did that can be found here Warum ich zu Linux wechsle if you can read German. I was so excited when I opened the project file of my Qt project. I developed the whole project in Windows and with a click of the “Compile & Run” button it was running under Linux. But the portability is not the only advantage. You have a huge Library with many classes solving different problems. If you want to use for example Network, no problem, just use it. The same goes for JSON support, XML, SQL, Bluetooth, OpenGL and many more. It’s just so convenient, you don’t have to search for a library, try to compile it and link it to your project, Qt does all that for you. So you don’t have to reinvent the wheel every time. At the beginning I mentioned reflection in Java. You can use reflection in Qt with the help of moc (Meta Object Compiler). So every class that inherits from QObject knows what class it is and other information at runtime.

Installing Redmine 3.0 on clean Ubuntu 14.04

Fri, 27 Mar 2015 13:10:00 +0200

In this tutorial we will install Redmine on a clean installation of Ubuntu server 14.04 with an Apache server and MySql. Redmine wil be reachable under the subdomain redmine.example.com.