TL;DR

There can be issues with the RRDTool package for Alpine Linux.

While reporting Issue 1145 for RRDTool, I found out that I was not using the latest-and-greatest version. What if this was a solved problem?

“No worries!” said my gullible personality. “Surely we can use Alpine Linux to quickly figure that out!”.

Yes, after talking about hearing voices from the back of my head, now I’m talking about multiple personalities. 2021 is the year of coming out.

So I turned to Docker to do a quick test:

host$ docker pull alpine:edge
host$ docker run --rm -itv "$PWD:/mnt" alpine:edge /bin/sh -l

container$ apk update
container$ apk add rrdtool
container$ sh rrd-graph.sh

The actual contents of shell program rrd-graph.sh are not important here… it’s just a command to generate a picture.

A horrible picture, actually:

In case you’re wondering, my let’s lose some time and sleep personality won the fight for trying to find out how many Alpine Linux releases had this problem. Well… a lot, and in particular all that contain version 1.7.2 of RRDTool, which was basically what I was after.

It seems that the basic font “Sony fixed” is somehow ignored.

The simplest solution that I found was to turn to another font, namely terminus-font:

container$ apk add terminus-font
container$ sh rrd-graph.sh

And now…

Yay!

Well… enough for today, see you soon folks!