Restrict SSH to rsync

Today I created limited access for a buildbot user via SSH. The build machines need SSH access to upload built software to our file server. This works using rsync over SSH.

Whereas real users are using a Yubikey and not SSH key files anymore, the build machines still require SSH …

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Download Wordpress Media Library

I’m currently in the process of migrating my old Wordpress blog to Pelican. In Wordpress it is easy to export all your posts as an XML file, but this does not export the referenced images. Also there is no export-all functionality, or FTP access or something like that. Downloading …

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Using virtualenv on Gentoo

When using Python you should always use your package mangager (portage on Gentoo) to install python software. Other tools like pip install would interfere with your system and can damage your local python installation.

But sometimes you need python modules which dont exist or are too old in your distribution …

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Setting KVM hostname per DHCP

The Problem

One problem with virtual machines is, when you clone one you also copy the complete configuration including hostname, static IPs, etc. To fix this you need to boot the cloned VM, edit the config and reboot it. The problem is that you will have at least temporary hostname …

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Profiling Memory using GNU glibc tools

One of the tools I’m using already quite a while to profile memory usage is the built-in profiling functionality in glibc. For some reason this isn’t known very much, so I thought documenting it here makes sense, so I can simply point the people to this post, instead …

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Latency Heatmaps

Latency heatmaps are a great way to visualize latencies which are hard to grasp from pure test data. Brendan Gregg (http://brendangregg.com) has written a great Perl script for generating such heatmaps as interactive SVG graphics. Also the flamegraphs are just awesome, but this is another story.

(Unfortunately SVGs …

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Using Let’s encrypt for non-web servers

I think I don’t need to explain Let’s encrypt anymore. But what many people are struggling with is to use Let’s encrypt certificates for other services like SMTP, IMAP, IRC, etc.

Using certbot this is quiet easy (See https://certbot.eff.org for installation instructions).

When certbot …

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Building MinGW Cross-Compilation Toolchain using CrossDev

This is mainly a note to myself. Maybe it’s useful for you too.

Actually building cross-compiler toolchains using crossdev is easy, but there are some pitfalls.

  • Remove any compiler environment variables before building, or the build will fail
  • For building MinGW toolchains the openmp useflag must not be set …
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CMake uninstall

CMake is a great tool when building cross-plattform software. It offers also install target so you can build and install software this way:

# create of-of-source build directory
mkdir bld
cd bld
# run CMake to generate a Makefile
ccmake ..
# Build in 4 cores
make -j 4
# Install into CMAKE_INSTALL_PREFIX (default is …
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New Keystroke GUI with Vim support

I’ve created an updated version of my Keystroke-gui keylogger, which can be controlled by Vim Hooks. Keystroke is keylogger and visualizer which can be used for screencasts. This is especially useful when recording screencasts for Vim, because in Vim’s normal mode you cannot see what is typed, opposed …

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ESA is using CDE?

Hi,

in the last days I was constantly watching the news regarding the ESA mission Rosetta. Wasn’t this impressing? Landing on a comet so far away?

Anyway, when looking at the various images on the ESA website I’ve seen some screens which were running this CDE style software …

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