Today is March 14th, or as many geeks refer to it: Pi day. On this occasion, I would like to show you a syslog-ng configuration, which prints a huge π on the screen, and two recent articles that feature syslog-ng on the Raspberry Pi.
Printing π
The following configuration – that I got from my colleagues – prints a huge π sign on screen. Create a new configuration, copy and paste the configuration below and save it on your host running syslog-ng with the name pi.conf:
@version: 3.31
@include "scl.conf"
template-function "pi-art" "
3.141592653589793238462643383279
5028841971693993751058209749445923
07816406286208998628034825342117067
9821 48086 5132
823 06647 09384
46 09550 58223
17 25359 4081
2848 1117
4502 8410
2701 9385
21105 55964
46229 48954
9303 81964
4288 10975
66593 34461
284756 48233
78678 31652 71
2019091 456485 66
9234603 48610454326648
2133936 0726024914127
3724587 00660631558
817488 152092096
";
block source pi-art(...) {
example-msg-generator(template("$(pi-art)") `__VARARGS__`);
};
log {
source { pi-art(); };
destination { file("/dev/stdout"); };
};
What happens in this configuration?
-
As usual, the syslog-ng configuration starts with a version number declaration. The current version is 3.31, but I also tested this config with syslog-ng version 3.26.
-
We include scl.conf (SCL is the syslog-ng configuration library). It contains many useful configuration snippets. None of them is used here, but we are too much used to including it :-)
-
We define a custom template function, called “pi-art” that shows a huge π sign.
-
The source block is also named “pi-art” and calls example-msg-generator() to print the π character once each second, using the previously defined template function.
-
Finally, the log statement connects the pi-art() source with the standard output (our screen).
How to test it? Start syslog-ng in the foreground with the freshly saved configuration:
syslog-ng -F -f pi.conf
syslog-ng on the Raspberry Pi
Recently, Pi day is not just about physics and mathematics (and eating pies), but also about the Raspberry Pi. Syslog-ng runs on these tiny machines and I contributed two articles to the Pi day article series on https://opensource.com/:
-
Containers became widely popular because of Docker on Linux, but there are much earlier implementations, including the jail system on FreeBSD. A container is called a `jail` in the FreeBSD terminology. The jail system was first released in FreeBSD 4.0, way back in 2000, and it has been continuously improved since then. While 20 years ago it was used mostly on large servers, now you can run it on your Raspberry Pi.
From this article, you can learn the major differences between containers on Linux and FreeBSD, getting started with FreeBSD on the Raspberry Pi, and creating your first two containers using Bastille, a jail management application for FreeBSD: https://opensource.com/article/21/3/bastille-raspberry-pi -
I have lived in 100-plus-year-old brick houses for most of my life. They look nice, they are comfortable, and usually, they are not too expensive. However, humidity is high in winter in my climate, and mold is a recurring problem. A desktop thermometer that displays relative humidity is useful for measuring it, but it does not provide continuous monitoring.
In comes the Raspberry Pi: it is small, inexpensive, and has many sensor options, including temperature and relative humidity. It can collect data around the clock, do some alerting, and forward data for analysis.
From this article, you can learn not just about how to forward sensor data from your Raspberry Pi to Elasticsearch using syslog-ng, but also how relative humidity is changing when opening the windows for shorter or longer periods of time: https://opensource.com/article/21/3/sensor-data-raspberry-pi
If you have questions or comments related to syslog-ng, do not hesitate to contact us. You can reach us by email or even chat with us. For a list of possibilities, check our GitHub page under the “Community” section at https://github.com/syslog-ng/syslog-ng. On Twitter, I am available as @Pczanik.
