Accessing NIFI Metrics endpoint for Prometheus without Authentication

[#1]

Hi 

We are currently in the process of upgrading our NIFI version to 2.0.0. But as per the below NIFI jira task PrometheusReportingTask has been completely removed from version 2.0.0 and added as a NIFI rest api endpoint.

https://issues.apache.org/jira/browse/NIFI-13507

The issue we are currently facing is that with old version 2.0.0-M2 metrics was exposed through PrometheusReportingTask which can be accessed without the need for any authentication and we were able to scrape the metrics to Prometheus.

But with the latest versions from 2.0.0 we have to provide the Bearer Token(Using OIDC) to access the metrics as it is a Rest API endpoint which is causing difficulties to integrate with Prometheus as we need to add an extra layer to get the token.

So my question here is, If there is any way to access the nifi-api/flow/metrics/prometheus without the need to provide any authentication which will solve our issue.

Any Suggestions are appreciated.

[#2]

@ravi_tadepally 
A secured NiFi is always going to require successful authentication and authorization.

I assume you are fetching a token because you have configured your secured NiFi to use OIDC based user authentication.  But keep in mind that a secured NiFi will always support Mutual TLS based authentication no matter what additional authentication methods have been configured.   For Rest-api interactions it is often easier to generate a clientAuth certificate that is trusted by your NiFi's truststore and use that instead for authentication.  With mutual TLS based authentication there  is no need to fetch any token.  You simply include the clientAuth certificate in every rest-api call.  

You could even handle this task via a NiFi dataflow that utilizes the invokeHTTP processor (configured with a SSL Context Service.  Could even just use NiFi's keystore and truststore) to make the rest-api call to fetch Prometheus data and then through that dataflow send it to the desired endpoint.

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Thank you,
Matt