J_K9 @ Linux

Seven.Ten Degrees of Modularisation

October 23, 2007 on 2:03 pm | In Linux, Server |

Ubuntu Server is a popular Linux server distribution which has been gaining some good ground over the past few years, but is still behind its main commercial rivals: Red Hat Enterprise Linux and SUSE Linux Enterprise Server. However, one of the new, experimental (but stable) features in Ubuntu 7.10 Server Edition is set to change the course of all server Operating Systems in the near future, and that feature is Tasks.

Ubuntu Server Tasks are preset configurations of popular server software which are installed if selected and configured using a simple interface. For example, choosing to install the Samba File Server task would fully install and pre-configure the Samba filesharing server, arguably the best and most commonly-used server filesharing technology (in the enterprise). It is also possible to choose a combination of tasks, such as the Print Server and Mail Server tasks. This means that, whereas before you had to select the software manually and do the necessary research to find out which software was best for the job, there are now default selections for what is considered to be the most suitable, reliable software for each task.

This has several positive implications:

1. As a security-minded individual, one of its most advantageous side-effects is the abstraction of extra software from the core components of the server. This means that only the software required for the server’s job is installed, thus minimising the risk of compromise to the system. It also allows systems administrators to install the core server and then build on that manually if they wish, allowing them to select the specific libraries and applications required—nothing more, nothing less.
2. It is now much easier to set up an Ubuntu server to perform the role you wish it to. That is, if you want a mail server, all you need to do is select the Mail Server task and then change some of the configuration files to suit your environment afterwards, and the same goes for many of the other tasks. This greatly simplifies the installation and management of an Ubuntu Server and means that the platform is now much easier to adopt in places where Linux knowledge is slim, such as in SMBs.
3. To extend the previous point, it is also less time-consuming for systems administrators to set up an Ubuntu server because they can quite simply select the tasks that match their requirements for that server and then do some post-installation configuration changes to complete the set-up.
4. Tasks may also be configured and customised by a systems administrator. If, for example, a systems administrator wanted to set up a selection of different Linux servers in a cluster, he could theoretically make his own task definining which applications are required for this purpose and then remaster an Ubuntu Server install CD to include this task and the default configuration files for that software. Then, he could simply use that CD and his own task to install an identical Ubuntu Server system on each of the servers with minimal effort.
5. This modular approach to the Ubuntu Server distribution also has huge potential for the future. The reason that many enterprises and SMBs are still using Microsoft’s Active Directory with Exchange is that the Open Source alternatives, LDAP and a groupware platform such as Scalix or Open-Xchange, are too difficult to set up (it’s particularly LDAP that’s the problem). What if an LDAP/groupware task with a simplified configuration tool (which would run after the installation) were added to Ubuntu 8.04 Hoary LTS (Long Term Support) Server Edition? In my opinion, this would boost the demand for Ubuntu Server enormously and would kickstart the replacement of Active Directory and Exchange with Open Source alternatives, both in the enterprise and in the often forgotten but very large education sectors.

However, this simplifed, modular approach to a Linux server distribution also has a few disadvantages:

1. It is now much easier to set up a Linux server for many different roles than it used to be. This means that it is installed by a greater quantity of less experienced administrators who forget or do not know how to configure or secure the server and its software after the installation process, which will inevitably result in an increase in compromised Linux servers and company losses due to the work of hackers and malware.
2. Open Source is about freedom and choice, and although these Tasks are chosen with the most reliable, advanced software in mind, sometimes user preference is the deciding factor. This makes it difficult to produce a selection of Tasks which will please the majority of Ubuntu Server administrators, because some prefer postfix over sendmail (SMTP mail server task), PostgreSQL over MySQL (database server task), Python over PHP (scripting language or environment task) and so on.

Personally, the advantages clearly outweigh the disadvantages and I am glad to see that a more modular approach is being adopted in the Server distribution of Ubuntu. The ability to add tight-knit groups of software which are known to work well together on top of a solid core makes the installation process simpler and faster, and also ensures that no unnecessary components are installed on your server.