Tutorial - Setup a dev environment for Munin
I discovered some time ago the marvelous
in the munin source code. So, as its usage is very easy, I'll just
write a tutorial about how to use it
To use it, one has to install all the packages needed for munin, and to grab a copy of the source code. Easiest is to use either a tarball, or to clone the git repository.
Note that the guidelines on contributing back are specified directly in the git repo.
Now, I just assume you want to contribute back, otherwise you would not care much about the said dev environment. That means using the git way of doing it.
Download the source code
First step is to clone the git repository. We will use
$HOME/src/munin as the development directory.
mkdir -p $HOME/src cd $HOME/src git clone https://github.com/munin-monitoring/munin munin cd munin
Now, we have to compile the source code. I know that it sounds strange as the code is mostly Perl, but there are some templates that need to be filled with the environment specifics, such as the Perl interpreter path, a POSIX compatible shell, ...
Now all munin (and munin-node) should be compiled and installed in
Note that the
1 at the end is explained below.
Using the dev tools
There are some different tools in
This is the one you used already. You have to use it every time you want to recompile & deploy the package.
1 argument, does a full re-install (wipe & install), so
you don't usually want to do that.
This is a tool to start the development node. Note that it listens on the port 4948, so you can use it alongside a normal munin-node.
run command inside is used to launch all the executable
parts of munin, such as
munin-limits. It can also be used to launch
The usage is very simple, just prefix the command to launch with
dev_scripts/run, every environment variable and command line
argument will be forwarded to the said command.
# launch munin-cron dev_scripts/munin-cron # launch manually some cron parts dev_scripts/munin-update dev_scripts/munin-limits dev_scripts/munin-html dev_scripts/munin-graph # debug a plugin dev_scripts/munin-run --debug cpu config
This is the same as
run, only for CGI. It sets up the whole
environment vars that emulates a CGI call. Usage is very easy :
dev_scripts/cgi munin-cgi-graph /localnet/localhost/cpu-day.png > out.dat
out.dat will contain the whole HTTP output, with the HTTP
headers and the PNG content. Everything that is sent to STDERR won't be
catched, so you can liberally use it while debugging.
query_munin_node is used to send commands to the node in a
very simple way. Node commands are just args of the tool.
dev_scripts/query_munin_node list dev_scripts/query_munin_node config cpu dev_scripts/query_munin_node fetch cpu
Real CGI usage with your web browser
That's the holy grail. You will have a development version that behaves the same as a real munin install.
First, let's assume you have a working user cgi configuration (ie
~user/cgi/whatever is working). If not you should refer yourself
to the local documentation of your preferred webserver. Note that nginx will
_not_ work, as it does
not support CGI.
I wrote a very simple cgi wrapper script. The home dir is hard coded in the script.
#! /bin/sh ROOT=/home/me/src/munin eval "$(perl -V:version)" PERL5LIB=$ROOT/sandbox/usr/local/share/perl/$version #export DBI_TRACE=2=/tmp/dbitrace.log exec perl -T -I $PERL5LIB $ROOT/sandbox/opt/munin/www/cgi/$CGI_NAME