Analysing performance problems with systemd

Posted by Steve on Sat 26 Sep 2015 at 18:06

Now that Systemd is the default init-system in fresh installations of Debian GNU/Linux it is worth highlighting some of the new features.

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Validating SPF and DKIM at SMTP-time with exim

Posted by Steve on Tue 4 Aug 2015 at 07:58
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In our recent articles we've discussed creating SPF-records to avoid spoofed mails, and the creation and setup for DKIM-signing emails, for a similar purpose. Here we'll look at the other side of the coin; performing DKIM and SPF testing on your incoming email.

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Tying together SPF and DKIM with DMARC

Posted by Steve on Mon 3 Aug 2015 at 19:35
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When it comes to increasing deliverabiity of email, and preventing spoofed/forged emails the preferred solution these days is DMARC, which allows the use of SPF and DKIM to be enforced for domains in a unified manner.

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Avoiding mail-spoofing with SPF

Posted by Steve on Sat 1 Aug 2015 at 17:34
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The Sender Policy Framework, or SPF, is an email-validation system which is designed to allow spoofed mails to be indentified. In this brief introduction we'll look at how you can configure your outgoing emails to take advantage of this validation.

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DKIM-signing outgoing mail with exim4

Posted by Steve on Wed 29 Jul 2015 at 06:28
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There have been several systems designed to prevent mail spoofing over the years, the two most prominent solutions are DKIM and SPF. Here we're going to document the setup of using DKIM to signing outgoing mails with Debian's default mail transfer agent, exim4.

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Setting up a personal secure apt repository

Posted by wijnen on Sun 24 May 2015 at 09:58

Packages under development aren't always ready to be in the main Debian archive. But that doesn't mean it should be hard for people to install them. When asking people to test programs, it is most convenient to present it in the

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Preventing SPAM connections with bird.

Posted by Steve on Fri 22 May 2015 at 07:25

Bird is an Internet routing daemon with full support for all the major routing protocols. It allows you to configure hosts to share routing information, via protocols such as BGP, OSPF, or even statically. Here we're going to look at using it to automatically blacklist traffic from SPAM-sources.

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Using the rubocop ruby code and style analyzer

Posted by Steve on Mon 9 Mar 2015 at 12:12
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If you're developing code that you expect others to read and work with then it is very important to pick a consistent style, and having a style-checker can make enforcing your choice much less painful. Here we'll take a look at the rubocop analyzer for Ruby.

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Easily working with multiple repositories (git, hg, etc)

Posted by Steve on Sun 8 Feb 2015 at 18:00
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There are situations where it is ueful to checkout multiple repositories, which might use different revision control systems, and operate upon them as a group. This is what the mr tool was designed for.

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An introduction to the attic backup program

Posted by Steve on Tue 23 Dec 2014 at 11:09
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Over the past year or two several new backup utilities have become popular. These new tools tend to avoid the use of tar.gz files, and just store backups as collections of files. Usually these storage areas are incrementally updated and avoid wasting space thanks to the detection of duplicate content. Here we're going to look at one of them in particular "attic".

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