CODEWITHSUNDEEP
prometheusprometheus-blackbox-exporter
rookie099
rookie099

Reputation: 2607

Prometheus blackbox exporter citing several modules per job

What is the semantics of a job for a Prometheus blackbox exporter that cites more than one module under params.module?

I guess it means that all modules are tried and the probe only succeeds if all of them succeed. All the examples I have come across employ only single modules (typically module: [http_2xx]), and I have not configured an example nor looked it up in the source code so far. Maybe someone here knows already/definitely from direct experience.

Upvotes: 5

Views: 3069

Answers (2)

stoqlt
stoqlt

Reputation: 43

You can configure multiple Blackbox Exporter modules in one job:

Forget defining the single module param for the job (although there would be a default http_2xx anyway). Instead, add a __param_module label to each of the different static_config lists.

Example from the forum post

static_configs:
  - targets: [ url1, url2, url3 ]
    labels:  { __param_module: http_2xx }

  - targets: [ 8.8.8.8, 8.8.4.4 ]
    labels:  { __param_module: icmp }

Another improvement could be to use the label module instead of __param_module. This way the module appears as a label in the Prometheus metrics. Of course, in this case you have to extend the usual relabel_configs with a new item:

relabel_configs:
  - source_labels:  [__address__]
    target_label:   instance
  - source_labels:  [__address__]
    target_label:   __param_target

  - source_labels:  [module]
    target_label:   __param_module

  - target_label:   __address__
    replacement:    localhost:9115

Upvotes: 0

Alin Sînpălean
Alin Sînpălean

Reputation: 10084

Based on the blackbox_exporter source code it would seem that every probe only ever executes a single test / module. Either you provide the module name in the request (as suggested by the documentation) or else it defaults to http_2xx.

The only way you could execute multiple modules would appear to be to define a separate Prometheus job, with a different module parameter value.

The only reason Prometheus' params is an array rather than a single value is that it's not limited to blackbox_exporter, it's a general way of sending HTTP parameters to a target (e.g. one might use something like /metrics?module=foo&module=bar to instruct the target to only return metrics for modules foo and bar).

I just tested from the browser and what happens if you query blackbox_exporter with multiple module parameter values, is that blackbox_exporter will ignore everything but the first value.

Upvotes: 6

Related Questions