A little tech blog

OpenBSD - Munin plugins missing libraries

Today I’ve decided to document how I installed my munin monitoring system on OpenBSD and how to make two plugins work in particular. I run an instance of Nginx and also a PostgreSQL server so I wanted my munin to be able to get some info about them. The fact is that you need some additionnal dependencies in order to make them return values properly. The two required libraries are p5-libwww (for the Nginx plugin) and p5-DBD-Pg (for the PostgreSQL one).

Linux - How to slow down the data flowing through a pipe

If for some reason you want to slow down the speed of a pipe between two process on Linux, you can use pv (pipe viewer). For example you can use it this way to transfer a file to another place at a slow speed. cat /home/user/file | pv -L 3k -q > /tmp/mynewfile You can adjust the speed with the number given to the -L parameter to pv. For example 1, 10, 100, 1k, 10k, 1m etc.

Nginx - SSL Proxy configuration

For a project at work I had to setup a SSL Proxy with nginx, because one of our old weblogic server can’t manage SHA2 certificates and we can’t update now. We decided to make it talk to a SSL Proxy and here is the code of the nginx.conf acting as such. It makes use of Nginx module http_proxy. As a little reminder we had a situation like this : serverA (client certificate) -> webservice (HTTPS / server certificate)

Web - How to test that your webserver is serving gzip pages

When you want to set up your webserver you might want to use gzip. But how to test if it works ? I used to test some request with telnet, the problem is that it will always return without gzip, because you don’t specify that you can process the gzip binary returned. So the webserver don’t use it. But there’s a solution available on all linux boxes. It requests headers only and specifies that it can handle gzip compression.