Is it possible to use REST Service to provide data for prometheus

[Thorsten Stork]

Hello,

I am really new to the prometheus topics, but should evaluate monitoring functionality 

for a system.

On this system (middleware) we kan provide REST Service, http-Services or webservices which can deliver some metrics at the current time (no historic data).

On this system we could not install exporter or other things like libraries or so.

How far I understand, Prometheus pulls the data from an exporter via REST oder http-call, is this right ?

So is the a definition how the service have to look like to simulate an "exporter" or my complete idea the wrong way ?

How should be the best way to solve my requirements ?

Thank you.

Regards

   Thorsten

[Christian Hoffmann]

Hi,

On 7/1/20 5:25 PM, Thorsten Stork wrote:
> I am really new to the prometheus topics, but should evaluate monitoring
> functionality 
> for a system.
>
> On this system (middleware) we kan provide REST Service, http-Services
> or webservices which can deliver some metrics at the current time (no
> historic data).
> On this system we could not install exporter or other things like
> libraries or so.
>
> How far I understand, Prometheus pulls the data from an exporter via
> REST oder http-call, is this right ?

Right, it's just a simple HTTP GET request which returns the metrics in
a defined format.

> So is the a definition how the service have to look like to simulate an
> "exporter" or my complete idea the wrong way ?

No need to "simulate". It's a completely valid way. :)

Depending on your environment and the programming language, it might be
easier to use one of the existing client libraries for that.

This documentation describes the format:
https://prometheus.io/docs/instrumenting/exposition_formats/

Kind regards,
Christian

[Thorsten Stork]

Thank you very much. I will try it out.

[Thorsten Stork]

Hi Christian, 

another question to this: How/where will the endpoint of my REST service configured, so prometheus will call ist it and get the values at the actual time ?

Thank you.

Regards

   Thorsten

Am Mittwoch, 1. Juli 2020 17:25:22 UTC+2 schrieb Thorsten Stork:

[Christian Hoffmann]

Hi,

On 7/2/20 8:15 AM, Thorsten Stork wrote:
> another question to this: How/where will the endpoint of my REST service
> configured, so prometheus will call ist it and get the values at the
> actual time ?

That's the scrape configuration.

https://prometheus.io/docs/prometheus/latest/configuration/configuration/#scrape_config

The simplest form is the static service discovery:
https://prometheus.io/docs/prometheus/latest/configuration/configuration/#static_config

The path defaults to /metrics, but can be changed (metrics_path).

Kind regards,
Christian