I’ve started using Apache-Exporter1 for monitoring and checking this weekend how useful it is and how it can be integrated into my Prometheus2 monitoring enviroment. The server-status requests inevitably lead to more “background noise” in the Apache logfiles. The screenshot below clearly shows in the upper less section: Of course the requests cannot be prevented, but you can manipulate what Apache writes in its logfiles. It’s called conditional logging and allows you to set variables with SetEnvIf3 to any regex on each request. With SetEnvIfExpr it is even possible to perform expressions4, for instance to check if a request comes from your inside network segments: Read more

Yesterday evening somebody desperately fought in despair with Packer, the younger sister of Vagrant. The goal was to create a testing farm of n machines for Virtualbox and make them accessible via SSH for further automated software testing/rollout. For me, this is much easier by using a simple bashscript. This morning I’ve made one even before the very first cup of coffee. #!/bin/bash # Pfad zur Master .ova Datei MASTER_OVA="$HOME/projects/testingfarm/DebianBuster.ova" # Anzahl der gewünschten VMs AMOUNT=2 # Name der VMs (Index und Datum werden noch angefügt = NAME-n-YYYYMMDD) PREF_VMNAME="debian" # Anzahl der CPUs PREF_CPU=1 # Zugewiesener Speicher PREF_MEMORY=1024 # Datums-Suffix THE_DATE=$(date +%Y%m%d) # Logdatei zum prüfen THE_LOG="$HOME/projects/testingfarm/$THE_DATE-$PREF_VMNAME.log" # -- Bitte ab hier nichts mehr manuell anpassen -- echo "Beginne Erstellen der Testumgebung... (Start: $(date +%T))" > $THE_LOG for ((i=1; i<= $AMOUNT; i++)) do vboxmanage controlvm $PREF_VMNAME-$i-$THE_DATE poweroff >> $THE_LOG vboxmanage unregistervm $PREF_VMNAME-$i-$THE_DATE --delete >> $THE_LOG vboxmanage import $MASTER_OVA --vsys 0 --cpus $PREF_CPU --memory $PREF_MEMORY --vmname $PREF_VMNAME-$i-$THE_DATE >> $THE_LOG vboxmanage startvm $PREF_VMNAME-$i-$THE_DATE --type headless >> $THE_LOG done echo "...fertig! (Ende: $(date +%T))" >> $THE_LOG The script creates n boxes based on its .ova MASTER. I assume that all network settings (if bridged, NAT or anything else) are specified there. Alongside with a transferred SSH-ID for Ansible, if necessary. The whole setup can of course be done without a master by using createvm inside the for-loop, your mileage may vary. Read more

Terminal Server - A look back The second part of the home office series is about terminalservers. The concept is quite old and we can’t avoid a short excursion into the past: It leads us back to the late 40s and 50s of the last century right to the beginnings of computer history. Computing time on such huge Von-Neumann-Computers1 was limited, very expensive and of course sometimes secret. Without going too much into details, I recommend the book by Kai Schlieter “Die Herrschaftsformel”2, which shows the developmental trajectories of computer science, defence technology, cybernetics and public relations. Read more

At the beginning of the (first?) Corona lockdown in March 2020, I was advised during an nightly Jitsi meeting by a befriended admin from Hamburg about giving Hugo a chance. Probably just after I dropped a rant about Rapidweaver, my previous static site generator on the Mac. Making of blog.jakobs.systems The idea needed to grow for almost half a year, till August, when I finally found a test balloon for Hugo: My personal blog and if everything succeeds, my official website, which is slowly getting rusty. Read more

Installing a Nextcloud instance is a snap. There are numerous tutorials and, on better NAS systems or hosting providers, even ready-to-use appliances that can be easily clicked together. When it comes to data backup, my observation is that the sources are rather limited and I would rather not use the few manuals that are available on the net. This blog post wants to help increase data protection with an automated, daily and complete backup for your Nextcloud. It is aimed at private users. The focus should not just rest on the script, but rather on the thoughts and considerations around it. Read more