Author: Lorenzo Boccaccia

Simple linux iptables configuration script

I had the necessity to firewall some VMs after installing a cluster of the awesome CockroachDB, since I couldn’t find out how to password protect the admin interface.   The idea is to drop all connections by default from all machines not in the cluster pool, while allowing unrestricted communication between machines within the pool from any port. The …

Read more

SysUsage: visualize all the stats of your vms

There are plenty professional monitoring solutions that provide alerts and monitoring facilities for Linux servers. They are mostly optimized for server administration and make it a little to hard for developers to understand their application resource usage under constrained environments. It is especially annoying that many of them only fetch data from SMNP agents, making …

Read more

Writing testable code

As written in The Mythical Man Month you either plan half of your schedule for testing or spend twice that debugging.   However writing tests is not easy. Mocking strategies and full system tests allow one to easily orchestrate the parts of the application that cannot be unit tested, but they come at a significant increase …

Read more