cleanup & mrtg article

2022-01-15 21:41:04 +01:00
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+---
+title: "MRTG - fun with 20th century monitoring solution"
+date: 2022-01-15T14:43:04+01:00
+draft: false
+tags:
+ - monitoring
+ - mrtg
+---
+
+ > I'm totaly aware there are more modern monitoring solutions (prometheus, icinga2, prtg and other 
+ hipster stuff) out there. Despite this, I still like MRTG's minimalist approach.
+
+![MRTG](/image/mrtg/mrtg.png#center)
+
+## (my) setup
+In my configuration MRTG is solely used for *collecting metrics* from various sources.
+MRTG is very flexible where these metrics come from (snmp, curl, scripts ...).
+My current configuration can be found at https://git.br0tkasten.de/br0tkasten/mrtg
+
+### backend
+
+#### installation
+In [Alpine](https://www.alpinelinux.org), mrtg can be installed with `apk add mrtg`.
+
+#### configuration
+Details on mrtg's config can be found in the [projects online documentation](https://oss.oetiker.ch/mrtg).
+You will find my configs in [my git project](https://git.br0tkasten.de/br0tkasten/mrtg/src/branch/master/config).
+
+**Example:**
+```
+LoadMIBs: /usr/share/snmp/mibs/UCD-SNMP-MIB.txt
+WorkDir: /var/www/mrtg/rrd
+LogFormat: rrdtool
+
+Target[br0tkasten.eth0]: #eth0:oom6faayaTosh0nizoepoonahCohhahy@10.3.0.1:
+Title[br0tkasten.eth0]: [br0tkasten] eth0 
+MaxBytes[br0tkasten.eth0]: 4294967295
+```
+
+### frontend
+
+#### cgi-bin/graph.pl
+A perl script is generating graphs from rrd using templates for each metric.
+
+```
+<img alt="br0tkasten.eth0 Traffic Graph" src="/cgi-bin/graph.pl?width=680&height=200&graph=br0tkasten.eth0">
+```
+##### Parameter
+- graph: name of the metric, the script will look for a template with the same name in tmpl/*.tmpl
+- width & height: dimensions of the returned image in pixel
+
+![cgi-bin/graph.pl](/image/mrtg/graph.png)
+
+##### Templates
+For each metric to be displayed you will have to create a template in tmpl/*metric*.tmpl.
+Templates use rrdgraph syntax. More details can be found at [the projects online documentation](https://oss.oetiker.ch/rrdtool/doc/rrdgraph.en.html)
+
+**Example: tmpl/br0tkasten.eth0.tmpl**
+```
+-v in/up bps 
+-t [br0tkasten] eth0
+--full-size-mode
+--color=BACK#343637
+--color=CANVAS#F0F0F0
+--color=FONT#F0F0F0
+--font=TITLE:12:DejaVu Bold
+DEF:d=/var/www/mrtg/rrd/br0tkasten.eth0.rrd:ds0:AVERAGE
+DEF:u=/var/www/mrtg/rrd/br0tkasten.eth0.rrd:ds1:AVERAGE
+CDEF:down=d,8,*
+CDEF:up=u,-8,*
+AREA:down#CC9A5780:Down
+AREA:up#2EA34960:Up
+LINE1:down#CC9A57
+LINE1:up#2EA349
+LINE1:0#000000
+```
+
+#### cgi-bin/details.pl
+Renders tmpl/details.tmpl to display a html page with a bigger version of the graph.
+Using [rrdGraphJs](https://github.com/oetiker/RrdGraphJS) you can interactively zoom and scroll in your graph.
+
+![cgi-bin/details.pl](/image/mrtg/details.png)
+
+#### html
+Graphs are embedded in static (and some dynamically generated) html pages.
+I like to keep things simple - so most content is static.
+Examples can be found in [htdocs](https://git.br0tkasten.de/br0tkasten/mrtg/src/branch/master/htdocs/index.html).
+
+```
+<div>
+	<b>[br0tkasten.de] eth0</b><br/>
+	<a href="/cgi-bin/details.pl?graph=br0tkasten.eth0">
+        <img alt="br0tkasten.eth0 Traffic Graph" src="/cgi-bin/graph.pl?width=680&height=200&graph=br0tkasten.eth0">
+    </a>
+</div>
+```