Ansible local_action privilege de-escalation or: how to wait for a reboot

I increasingly use Ansible not only for glorious tasks like setting up my various VMs I use for prototyping but also for mundane things like resetting my personal laptop every time I get a new one or break it (dedicated readers of this blog will know me to do that a lot [2],[3],[4]). Most of … Continue reading Ansible local_action privilege de-escalation or: how to wait for a reboot →

Securing a development server

In this post I talk about setting up and securely operating development tools like Jenkins and Gitlab on a server connected to the internet. All applications run behind a firewall and a reverse HTTP proxy which allows only HTTP requests from selected users through who authenticate themselves with client certificates. Putting web-facing software on the … Continue reading Securing a development server →

Building a private cloud with Docker

Abstract: In this post I'll describe how to create a private cloud with Docker, Varnish and a lot of shell scripting on a set of private (virtual) servers. This post assumes intermediate knowledge of related techniques. I will still once in a while go into setup details because, well, this is also an exercise for … Continue reading Building a private cloud with Docker →

Tomcat starts slowly in docker container

Just a little reminder to self: when running Tomcat with Java 8 in an Ubuntu Docker container, Tomcat will take a very long time (minutes!) to start with even the simplest web application. The issue is actually documented (not entirely Docker-related). The solution is to modify JAVA_OPTS to use a different random device: JAVA_OPTS=-Djava.security.egd=file:/dev/urandom

Formatting USB flash drives for write speed

Flash drives enjoy a reputation for being fast and that certainly goes for high-end models with their elaborate memory controllers and multi-bank layouts. A fundamental "problem" with current flash memory technology is that writing even a single bit of information requires that an entire block of flash memory is reset first [1], which greatly reduces … Continue reading Formatting USB flash drives for write speed →