Home Page

Category: linux

Disable "New release available" emails on Ubuntu

We have our Ubuntu machines set up to mail us the output of cron jobs like so: $ cat /etc/crontab SHELL=/bin/sh PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin MAILTO=admin@example.com # m h dom mon dow user command This is encrible useful, since cronjobs should never output anything unless something is wrong. Unfortunately, this means we also get emails like this: /etc/cron.weekly/update-notifier-common: […]

cfgtrack: A simpel tool that tracks and reports diffs in files between invocations.

Sometimes other people change configurations on machines that I help administer. Unfortunately, I wouldn't know when they changed something or what they changed. There are many tools available to track configuration changes, but most are way overpowered. As a result they require too much time to set up and configure properly. All I want is […]

Alien Deb to RPM convert fails with error: "Use of uninitialized value in split…" [FIXED]

TL;DR: Run alien under the script tool. I was trying to get my build server to build packages for one of my projects. One step involves converting a Debian package to a RPM by means of the Alien tool. Unfortunately it failed with the following error: alien -r -g ansible-cmdb-9.99.deb Warning: alien is not running as root! […]

Terrible Virtualbox disk performance

For a while I've noticed that Virtualbox has terrible performance when install Debian / Ubuntu packages. A little top, iotop and atop research later, and it turns out the culprit is the disk I/O, which is just ludicrously slow. The cause is the fact that Virtualbox doesn't have "Use host IO cache" turned on by […]

mdpreview, a Markdown previewer to be used with an external editor

There are many Markdown previewers out there, from the simplest commandline tool + webbrowser to full-fledged Markdown IDE's. I've tried quite a few, and I like none of them. I write my Markdown in an external editor (Vim), something very few Markdown previewers take in account. The ones that do are buggy. So I wrote mdpreview, […]

Openvas v8 on Ubuntu 14.04: Login failed. OMP service is down

Recently I suddently couldn't log into Openvas v8 running on Ubuntu 14.04 anymore. Nothing had changed about the machine (as far as I knew), but I got the following message when trying to log in with any account: Login failed. OMP service is down The logs (/var/log/openvas/openvasmd.log) showed the following message: lib serv:WARNING:2016-01-19 15h52.12 utc:21760: […]

Introducing ScriptForm: Stand-alone webserver that generates forms to serve as frontends to scripts

I've just releases v1.0 of ScriptForm. ScriptForm is a stand-alone webserver that automatically generates forms from JSON to serve as frontends to scripts. It takes a JSON file which contains form definitions, constructs web forms from this JSON and serves these to users over HTTP. The user can select a form and fill it out. When […]

Interesting links: October 4th 2015

Here's a bunch of links I found interesting in the last few weeks: List of Python Report Generation Tools jstat – Java Virtual Machine Statistics Monitoring Tool How To Protect WordPress with Fail2Ban on Ubuntu 14.04 | DigitalOcean Shiny Turn your analyses into interactive web applicationsNo HTML, CSS, or JavaScript knowledge required logtail(8) – Linux […]

Batch create new users on Linux

A while ago I had to create many new users on a Linux machine. Since I'm lazy, I opted to automate this process. The newusers command combined with pwgen (to generate new passwords) was the solution. First I installed pwgen, a utility to automatically generate passwords: $ sudo apt-get install pwgen I created a file […]

Auto-mount external USB disk on a server

Althought modern Linux desktops generally automatically mount external USB disks when plugged in, servers usually don't do this. When I replaced my home server desktop model with a Raspberry Pi 2 (running Raspbian), I wanted it to automatically mount USB drives and, more importantly, make the same USB drive available at the same path at […]