Creative Commons License

Unless otherwise expressly stated, all original material of whatever nature created by and included in this weblog is licensed under a Creative Commons License.


The Comet Is Coming

The Comet Is Coming is a 21st century style Jazz band.
Discovered at the Jazznojazz festival :-)

11:04 | Music | Permalink


More productive Git

More productive Git — a short article from James Turnbull with 'Tips for acquiring Git super powers'.


  • git reset <filename>
  • git cherry-pick <commitid>
  • git commit --amend
  • git stash
  • git log --stat
  • git bisect

07:47 | Coding | Permalink


Engineering Management

Engineering Management: The Pendulum Or The Ladder — a well written article from Charity Majors about the non-trivial entanglement between engineering and management, explaining how doing everything at the same time does lead to unhappy/un-fulfilled people. Also worth reading in this context is the prequel article The Engineer/Manager Pendulum.

13:21 | Coding | Permalink

Blogroll cleanup

As some links on my blogroll start to turn into 404 errors it's time to do some cleanup and also to bring in some fresh blood :-)



12:55 | Misc | Permalink


New Year - New Vim Trick

Happy 2019! I have learnt a new Vim trick:
When searching for some pattern with / (eg. /mystring), often the next step is to perform a replacement command. Now instead of re-typing the whole string, you can directly enter the substitution command with an emtpy search-pattern (:%s//newstring/), Vim then automatically re-uses the previous search pattern.


22:24 | Coding | Permalink


The Swiss Army Knife of Hashmaps

The Swiss Army Knife of Hashmaps — a very nice article from Ravi Shankar explaining how Google's SwissTable concept was implemented for Rust.

06:41 | Coding | Permalink


Run QRadar CE on Mac OS X with Vagrant

The Vagrant file provided by IBM for running QRadar Community Edition on Mac OS X currently does not work properly. It fails with the following error:

Failure: repodata/repomd.xml from centos-gluster38: [Errno 256] No more mirrors to try. [Errno 14] HTTP Error 404

The problem is that gluster3.8 was moved out of this CentOS repository and now the download fails. But the gluster3.8 RPMs are also provided with the QRadar CE installation ISO file.

Based on the workaround described here, I've extended the IBM provided Vagrantfile so that the RPMs are taken from the ISO file instead of the CentOS repository. With the modified Vagrantfile the automatic provisioning script no longer fails.

The instructions for running QRadar CE with Vagrant now look like this:

  1. Download the zipfile with the original Vagrantfile and the accompanying helper files from the IBM website:
  2. Create a folder and extract the zipfile:
    mkdir community_edition
    unzip -d community_edition/
  3. Download the modified Vagrantfile and overwrite the original one:
    curl -o community_edition/Vagrantfile
  4. Make sure you have the requried Vagrant plugins installed:
    vagrant plugin install vagrant-disksize
    vagrant plugin install vagrant-reload
  5. Make sure you have the QRadar CE ISO file (downloaded from the IBM website) in the same folder as the Vagrantfile:
    cp QRadarCE.iso community_edition/
  6. Create the auto_install file to automatically install QRadar:
    touch community_edition/auto_install
  7. Accept the EULA by adding the corresponding setup parameter in the Vagrantfile:
    Edit the Vagrantfile and add the --accept-eula argument to /media/cdrom/setup --no-screen to automatically accept the EULA
  8. Change into the folder and start the QRadar installation (takes about 1 hour):
    cd community_edition
    vagrant up

13:18 | Networking | Permalink


Raid The Arcade

Raid The Arcade Mix

Ernest Cline - Armada

15:31 | Music | Permalink



Added another interesting blog to the Links:

Ben builds and writes about a lot of funny small projects:

07:16 | Misc | Permalink


Exclude domain from unknown sender check

Postfix provides the reject_unknown_sender_domain check which allows to only accept incoming e-mails sent from domains which actually exist.

Unfortunately there exists this one external service which uses a non-existing subdomain to send their notification e-mails. Thus all their notifications get rejected.

The following configuration allows to keep the reject_unknown_sender_domain check in place, but to exclude a specific domain from this check.

# snippet in
smtpd_sender_restrictions = check_sender_access pcre:/etc/postfix/sender_domain_verification
# exclude regex in sender_domain_verification
!/@domain\.to\.exclude\.com$/ reject_unknown_sender_domain

Your distribution might ship Postfix support for pcre matches in a dedicated package which needs to be installed separately (in the case of Debian you need to install the postfix-pcre package).

23:03 | Linux | Permalink