ubuntu on Andrés Álvarez

Debian Package Versioning

Thu, 13 Apr 2017 00:00:00 +0000

In a previous post I talked about managing Debian package dependencies. However I did not go into detail about the structure the versioning of packages must have.

To recap, let's see how we can specify a specific package version of a dependency that our package needs:

Depends: erlang (>= 1.2)

In the example above, the required version for erlang is simply 1.2 or greater. A package's version format however, can be a bit more complex than this.

Version Format and Components

The official format of a Debian package's version is:

[epoch:]upstream_version[-debian_revision]

Let's go into detail about each of the components in that format.

Setting Up an OpenStack Dev Environment

Wed, 22 Mar 2017 00:00:00 +0000

Before beginning to contribute to OpenStack, it is necessary that we setup an ideal development environment for a smoother workflow.

In this post I will cover how to setup a Devstack development environment in a Ubuntu 16.04 virtual machine using VMware Player.

Setting Up the Ubuntu Virtual Machine

Make sure you have VMware Player installed in your system. Then we need to choose an appropriate Ubuntu ISO image for our virtual machine. In my case I am using a Ubuntu Desktop 16.04.2 LTS (Xenial Xerus) for 32-bit PC i836.

In VMware Player, create a new virtual machine using the wizard. Assign your preferred amount of memory and storage space. Now start the machine, and select the Ubuntu .iso image file when prompted. Proceed with the installation and select the Erase Disk and Install Ubuntu option when prompted.

~> I tried using VirtualBox for virtualization but I could not successfully install Devstack with it. Probably due to issues on using the correct network adapter. I also tried using Ubuntu 14.04 without success as well. This is why I recommend Ubuntu 16.04.

Once the installation is finished, restart the virtual machine.

Managing Debian Package Dependencies

Fri, 14 Oct 2016 00:00:00 +0000

In a previous post, I talked about building a simple Debian package in Ubuntu, however I did not go into details on how to manage the dependencies that your Debian package might require. In this post I will cover exactly that.

dpkg and Dependencies

Previously we installed our package using the dpkg -i command. However, the problem with dpkg is that by itself, it is not capable of managing repositories. Therefore, higher level tools (such as apt-get) are required to fetch dependencies from repositories.

dkpg is only the core tool that installs/removes/configures packages, taking care of dependencies and other factors. apt-get and aptitude are tools that manage repositories, download data from them, and use dkpg to install/remove packages from them. This means, that apt-get and aptitude can resolve dependencies and get required packages from repository, but dpkg cannot, because it knows nothing about repositories.

Debian Packaging in Ubuntu

Tue, 11 Oct 2016 00:00:00 +0000

Debian packaging is a nice way to organize our software so that it can be installed and uninstalled with more ease. In this post we will go through the basics of creating a simple Debian package in Ubuntu 14.04 LTS.

Package Source & Structure

We will first create our working space for our package along with the necessary basic structure needed. For this example, we will create a directory for our package source, using the package title and 3 digit versioning in the directory's title:

mkdir mypackage-1.0.0

Inside our package, we will need a directory where we will hold the control files that give the Debian package the desired behavior:

cd mypackage-1.0.0
mkdir DEBIAN
touch DEBIAN/control

This control file will describe our package to the Debian package manager (dpkg). Inside, we can specify information about the package such as version, architecture, dependencies, maintainer, etc, as shown below:

Package: mypackage
Version: 1.0-0
Section: base
Priority: optional
Architecture: all
Depends: python2.7
Maintainer: Andres Alvarez <myemail@gmail.com>
Description: A new and improved C++ Compiler

With this basic setup, we now have a basic working package that can be handled by the Debian package manager, albeit, with no contents.