I'm having a problem in one of my servers, where munin is not able to write the text that accompanies each graph correctly. It is written as random squares, but I haven't found anything in the logs that could point me to the problem.
Anyone had a similar problem? Thanks in advance, Simon.
UPDATE
I've found some lines in /var/mail/root regarding some problem with pango:
Pango-WARNING **: failed to choose a font, expect ugly output. engine-type='PangoRenderFc', script='latin'
This could either be a problem with rrd, or a munin plugin.
Check the munin-graph.log and see if you have anything like this;
[RRD ERROR] Unable to graph <filename> : failed to load : failed to load $libdir/Some_Font_File.ttf
Another possibility is that munin is not able to read the font files in question (eg: the owner, group, or permissions are "wrong"), or there's a plugin interfering with the rendering.
Depending on the version of munin you're running, there should be a munin-check command that will fix various permissions (please read the man page before using, there's at least one caveat)
EDIT: This could also be an encoding problem. There's a bug where munin assumes everything is going to be in ISO-8859-1. A fix-request was filed and munin 1.3 and higher should use Encode::Guess now (details).
EDIT #2: Thanks to the additional comments, we now know two important things;
1) Software versions involved are
2) There are multiple servers w/ this configuration, and only one is broken.
Therefore, there is probably a slight difference in the shell environment settings between two of the servers (the "broken" server versus a "known-good" server).
Compare the Shell Environments on "broken" server & a "known-good" server
1) Login to the user-account the graphs are being generated with
2) Run env | sort > ~/shell_environment-User_Name-Server_Name.txt
(Replace "User_Name" and "Server_Name" with the actual names involved.)
3) Copy both shell_environment-*.txt files to a single place and compare them.
There's probably a variable (maybe $LANG) that's different and breaking the rendering.
On alpine I ran apk add ttf-opensans and su-exec munin:root munin-cron
You can see that it is starting to work as graphs refresh
