nixpkgs/nixos/modules/services/monitoring/munin.nix
2015-04-01 13:57:36 -07:00

217 lines
6.2 KiB
Nix

{ config, lib, pkgs, ... }:
# TODO: support munin-async
# TODO: LWP/Pg perl libs aren't recognized
# TODO: support fastcgi
# http://munin-monitoring.org/wiki/CgiHowto2
# spawn-fcgi -s /var/run/munin/fastcgi-graph.sock -U www-data -u munin -g munin /usr/lib/munin/cgi/munin-cgi-graph
# spawn-fcgi -s /var/run/munin/fastcgi-html.sock -U www-data -u munin -g munin /usr/lib/munin/cgi/munin-cgi-html
# https://paste.sh/vofcctHP#-KbDSXVeWoifYncZmLfZzgum
# nginx http://munin.readthedocs.org/en/latest/example/webserver/nginx.html
with lib;
let
nodeCfg = config.services.munin-node;
cronCfg = config.services.munin-cron;
muninPlugins = pkgs.stdenv.mkDerivation {
name = "munin-available-plugins";
buildCommand = ''
mkdir -p $out
cp --preserve=mode ${pkgs.munin}/lib/plugins/* $out/
for file in $out/*; do
case "$file" in
plugin.sh) continue;;
esac
# read magic makers from the file
family=$(sed -nr 's/.*#%#\s+family\s*=\s*(\S+)\s*/\1/p' $file)
cap=$(sed -nr 's/.*#%#\s+capabilities\s*=\s*(.+)/\1/p' $file)
wrapProgram $file \
--set PATH "/var/setuid-wrappers:/run/current-system/sw/bin:/run/current-system/sw/bin" \
--set MUNIN_LIBDIR "${pkgs.munin}/lib" \
--set MUNIN_PLUGSTATE "/var/run/munin"
# munin uses markers to tell munin-node-configure what a plugin can do
echo "#%# family=$family" >> $file
echo "#%# capabilities=$cap" >> $file
done
# NOTE: we disable disktstats because plugin seems to fail and it hangs html generation (100% CPU + memory leak)
rm -f $out/diskstats
'';
buildInputs = [ pkgs.makeWrapper ];
};
muninConf = pkgs.writeText "munin.conf"
''
dbdir /var/lib/munin
htmldir /var/www/munin
logdir /var/log/munin
rundir /var/run/munin
${cronCfg.extraGlobalConfig}
${cronCfg.hosts}
'';
nodeConf = pkgs.writeText "munin-node.conf"
''
log_level 3
log_file Sys::Syslog
port 4949
host *
background 0
user root
group root
host_name ${config.networking.hostName}
setsid 0
# wrapped plugins by makeWrapper being with dots
ignore_file ^\.
allow ^127\.0\.0\.1$
${nodeCfg.extraConfig}
'';
in
{
options = {
services.munin-node = {
enable = mkOption {
default = false;
description = ''
Enable Munin Node agent. Munin node listens on 0.0.0.0 and
by default accepts connections only from 127.0.0.1 for security reasons.
See <link xlink:href='http://munin-monitoring.org/wiki/munin-node.conf' />.
'';
};
extraConfig = mkOption {
default = "";
description = ''
<filename>munin-node.conf</filename> extra configuration. See
<link xlink:href='http://munin-monitoring.org/wiki/munin-node.conf' />
'';
};
# TODO: add option to add additional plugins
};
services.munin-cron = {
enable = mkOption {
default = false;
description = ''
Enable munin-cron. Takes care of all heavy lifting to collect data from
nodes and draws graphs to html. Runs munin-update, munin-limits,
munin-graphs and munin-html in that order.
HTML output is in <filename>/var/www/munin/</filename>, configure your
favourite webserver to serve static files.
'';
example = literalExample ''
services = {
munin-node.enable = true;
munin-cron = {
enable = true;
hosts = '''
[''${config.networking.hostName}]
address localhost
''';
extraGlobalConfig = '''
contact.email.command mail -s "Munin notification for ''${var:host}" someone@example.com
''';
};
};
'';
};
extraGlobalConfig = mkOption {
default = "";
description = ''
<filename>munin.conf</filename> extra global configuration.
See <link xlink:href='http://munin-monitoring.org/wiki/munin.conf' />.
Useful to setup notifications, see
<link xlink:href='http://munin-monitoring.org/wiki/HowToContact' />
'';
};
hosts = mkOption {
example = ''
[''${config.networking.hostName}]
address localhost
'';
description = ''
Definitions of hosts of nodes to collect data from. Needs at least one
hosts for cron to succeed. See
<link xlink:href='http://munin-monitoring.org/wiki/munin.conf' />
'';
};
};
};
config = mkMerge [ (mkIf (nodeCfg.enable || cronCfg.enable) {
environment.systemPackages = [ pkgs.munin ];
users.extraUsers = [{
name = "munin";
description = "Munin monitoring user";
group = "munin";
uid = config.ids.uids.munin;
}];
users.extraGroups = [{
name = "munin";
gid = config.ids.gids.munin;
}];
}) (mkIf nodeCfg.enable {
systemd.services.munin-node = {
description = "Munin Node";
after = [ "network.target" ];
wantedBy = [ "multi-user.target" ];
path = [ pkgs.munin ];
environment.MUNIN_PLUGSTATE = "/var/run/munin";
preStart = ''
echo "updating munin plugins..."
mkdir -p /etc/munin/plugins
rm -rf /etc/munin/plugins/*
PATH="/var/setuid-wrappers:/run/current-system/sw/bin:/run/current-system/sw/bin" ${pkgs.munin}/sbin/munin-node-configure --shell --families contrib,auto,manual --config ${nodeConf} --libdir=${muninPlugins} --servicedir=/etc/munin/plugins 2>/dev/null | ${pkgs.bash}/bin/bash
'';
serviceConfig = {
ExecStart = "${pkgs.munin}/sbin/munin-node --config ${nodeConf} --servicedir /etc/munin/plugins/";
};
};
}) (mkIf cronCfg.enable {
services.cron.systemCronJobs = [
"*/5 * * * * munin ${pkgs.munin}/bin/munin-cron --config ${muninConf}"
];
system.activationScripts.munin-cron = stringAfter [ "users" "groups" ] ''
mkdir -p /var/{run,log,www,lib}/munin
chown -R munin:munin /var/{run,log,www,lib}/munin
'';
})];
}