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The following tip was developed using Ubuntu 9.1x (Hardy Heron) with OpenVPn 2.1rc19. It builds on the the setup from Part I.

This post has been updated since publication to include FORWARD directives for the strangers list as well.

Part I of this guide to configuring a local firewall for OpenVPN introduced you to using iptables on Linux. It also included a script for OpenVPN that opened and closed the firewall for specific IP addresses. If you haven’t read it already, you should probably... [More]

The following tip was developed using Ubuntu 9.1x (Hardy Heron) with OpenVPn 2.1rc19.

Once you’re done with this tutorial, make sure to read Part II, which includes some crucial updates.

There are dozens of guides around that describe how to optimally configure the iptables firewall on Linux for OpenVPN. There’s even a script installed by default that is extremely well-commented and shows to how close down the firewall, then open up only very selected ports and protocols for optimal... [More]

At Encodo, we use Quino to model our databases for our projects when we can. Quino spoils us by automatically taking care of a lot of the grunt work involved in creating and maintaining a schema that performs well. Automatically creating indexes for foreign key fields is such a nicety.

On a recent project, we decided to try using Microsoft’s Entity Framework (EF) instead of embedding Quino. Unlike Quino, EF uses the database as the model, so we had to get used to writing models using the... [More]

At Encodo, we currently run Debian Etch on our servers, with a Xen hypervisor managing a bunch of individual virtual machines (VMs). Most of the VMs also run Debian Etch, but one of them runs Windows Server 2003 instead. We use this machine for testing integration with Microsoft technologies like Sharepoint, Exchange and so on. Recently, we had to re-install the Exchange instance on that server and were faced with the problem of having to change the CD without rebooting the VM. Luckily, we... [More]

Email used to be a very efficient means of communication. Nowadays, it’s become much less efficient due to spam. People who used to have a few messages per day—from people they knew and about topics in which they were interested—now find themselves inundated with hundreds of messages per day, all trying to sell them something. This extra mail is called “spam”; here’s an official definition:

Es war einmal − eine neue effiziente Kommunikationstechnologie mit Namen E-Mail. Heute hat uns Spam die Effizienz weitgehend zunichte gemacht. Leute, die früher einige E-Mail am Tag bekamen − von Freunden und Geschäftspartnern über Themen an denen sie interessiert waren − können heute mit hunderten von Mitteilungen überschwemmt werden und jeder will etwas verkaufen. Diese zusätzlichen ungewollten E-Mails nennt man ‘Spam’, hier eine offizielle Definition:

Viele von uns werden täglich von der Informationsflut aus dem Internet überrollt. Dieser Artikel soll zwei Technologien zeigen, wie man diese Flut eindämmen oder mindestens den Kopf wieder über Wasser bekommen kann.

Will man über ein Thema, eine Website oder eine Firma auf dem Laufenden bleiben, müsste man regelmässig die entsprechenden Websites besuchen und nach neuen, interessanten Informationen absuchen. Dies nimmt schnell viel Zeit in Anspruch. Was tun, wenn man auf dem Laufenden bleiben... [More]

The XWiki.org site integrates—and has for a while—a search that’s different from the standard one. It offers users the ability of restricting a search to a specific space instead of searching all spaces at once. Here at Encodo, we’ve been keeping our weekly reports in the wiki for years and these reports have continuously muddied our search results. The new search is a great improvement over the original.

Everything you see in XWiki is editable in one way or another and that includes the... [More]

As mentioned in the previous article, one of the loose ends to clear up is importing into separate spaces. One of the reasons we moved to XWiki was for the multiple namespace support; it would have been a shame to import all of our existing data into one, gigantic namespace.

Importing separate spaces

What we’ve got after running wikifetch.pl is one directory with all MediaWiki pages in it and all links pointing to the space MySpacePlaceholder.

First, we needed to decide which page goes... [More]

Once you’ve got an XWiki up and running (whether you imported a Mediawiki or not), you’ll find you want to tweak the standard rollout a bit.

Speeding up XWiki

After working a while with XWiki, you may notice it getting slower. Our XWiki was kind of slow from the get-go and we pretty quickly figured out why: the slowdown was caused almost entirely by the pretty, DHTML list of all pages in the panel on the right side. It apparently takes quite some time to build this list (and ours included... [More]

Previously…

In part I we talked about how to get the information out of our old wiki and tranform it to the new format.

The harvested and converted content of our old MediaWiki is now in a flat directory located on our hard drive. But these hundreds of files would require a serious copy-paste action on our behalf, which we’re not willing to participate in. Thus we’re getting some help from groovy.

Importing

XWiki has an XML-RPC interface which allows us to sneak our pages in. Using... [More]

Der Begriff Firewall (auf Deutsch übersetzt “Feuerschutzwand”) ist heute in aller Munde, wenn es um Sicherheit im Internet geht. Da Computer und Feuer nicht so recht zusammenpassen, stellt sich die Frage, woher der Begriff stammt. Im Hausbau dient eine Feuerschutzwand dazu, ein ausgebrochenes Feuer von anderen Gebäudeteilen abzuschotten. Auf den Computer übertragen, heisst dies, dass die Firewall einen Computer oder ein ganzes Netzwerk schützen soll. Der Schutz richtet sich dabei nicht gegen... [More]

Unlike most other major version changes in software[1], you don’t need to upgrade anything, buy anything or even do anything in order to use version 2.0 of the web—in fact, you’ve probably already used it!

As indicated in the article, What Is Web 2.0 (O'Reilly), the term originally arose from a “conference brainstorming session between O’Reilly and MediaLive International”. c indicates the shift in emphasis from a relatively strong separation between content producers and content consumers (or browsers) to... [More]

Most computer software has some sort of a version number. The version is composed of two to four numbers, separated by decimal points. More recently, some mainstream products have taken a page from the automobile industry by using the year the product was issued in the product name. Even these products, however, have an internal version number, usually available from an “About this application…” information dialog.

These three numbers are called the major, minor, revision and build numbers.... [More]

Fast immer, wenn im Computer-Bereich eine Versionsänderung angekündigt wird, ist man gezwungen den Rechner zu upgraden oder zumindest neue Lizenzen zu kaufen. Im Fall von Web 2.0 muss man gar nichts tun, um es zu benutzten – wir haben es vermutlich alle schon benutzt!

Wie im Artikel What Is Web 2.0 (O'Reilly) beschrieben wurde dieser Begriff bei einer Sitzung von O’Reilly und MediaLive International erfunden. Damit wollen sie ein neues Internet beschreiben, das auf dem Modell der Kollaboration basiert... [More]