prometheus-nagios-exporter

The Prometheus Nagios exporter reads status and performance data from nagios plugins via the MK Livestatus Nagios plugin and publishes this in a form that can be scrapped by Prometheus.

Setup

Setup is as simple as installing the livestatus module and then running the nagios_exporter.py service.

echo 'broker_module=/usr/lib/check_mk/livestatus.o /var/lib/nagios3/rw/livestatus' >> /etc/nagios3/nagios.cfg
echo 'event_broker_options=-1' >> /etc/nagios3/nagios.cfg

Restart Nagios, and start the exporter:

./nagios_exporter.py --path /var/lib/nagios3/rw/livestatus

It should then be possible to visit:

http://localhost:9267/metrics

Metrics

Every metric is prefixed with nagios_, following the metric naming best practices. The prefix is followed by the name of the Nagios check command, such as nagios_check_load_. The metric name suffix comes from various Nagios status names. For example, a load service check for localhost would include the following metrics:

nagios_check_load_exec_time{hostname="localhost", service="Load"} 0.011084
nagios_check_load_latency{hostname="localhost", service="Load"} 0.078
nagios_check_load_state{hostname="localhost", service="Load"} 0
nagios_check_load_flapping{hostname="localhost", service="Load"} 0
nagios_check_load_acknowledged{hostname="localhost", service="Load"} 0

Every metric is also labeled with the hostname and service description.

Performance data

Performance data is plugin-specific. Though there is a common format that most plugins follow. Performance data follows plugin output starting with |. Typically, the format is a set of key=value1[;value2]+ strings. For example:

$ check_disk <some args>
DISK OK - free space: / 2400 MB (69% inode=83%);| /=2400MB;48356;54400;0;60445

By default, nagios-exporter only parses the first value of performance data for every key. The default field name is 'value'. And, the key is always added as a metric label. So, for example, the default metric output for the above performance data would be:

nagios_check_disk_perf_data_value{key="/", ...} 2516582400.0

More specific names can be assigned to each value position of particular check plugins using the --data_names flag. For example:

--data_names="check_disks=used;free;;;total"

So, instead of only parsing the first value and using the default name, now the metric output for the original example will include three values each named and corresponding to the respective value in the raw perf data:

nagios_check_all_disks_perf_data_used{key="/", ...}  2516582400.0
nagios_check_all_disks_perf_data_free{key="/", ...} 50704941056.0
nagios_check_all_disks_perf_data_totalkey="/", ...} 63381176320.0

Example

    ./nagios_exporter.py --path /var/lib/nagios3/rw/livestatus \
        --perf_data --perf_names="check_disks=used;free;;;total" \
        --whitelist nagios_check_all_disks_perf_data