Enable Prometheus Plugin on Jenkins

[lordofthejars]

To enable metrics in Jenkins instances we need to enable Prometheus Jenkins plugin in our base image.

Apart from that we need to configure the plugin accordantly by creating a org.jenkinsci.plugins.prometheus.config.PrometheusConfiguration.xm with next content:

<?xml version='1.1' encoding='UTF-8'?>
<org.jenkinsci.plugins.prometheus.config.PrometheusConfiguration plugin="prometheus@1.1.1">
  <urlName>metrics</urlName>
  <additionalPath></additionalPath>
  <defaultNamespace>default</defaultNamespace>
  <useAuthenticatedEndpoint>false</useAuthenticatedEndpoint>
  <countSuccessfulBuilds>true</countSuccessfulBuilds>
  <countUnstableBuilds>true</countUnstableBuilds>
  <countFailedBuilds>true</countFailedBuilds>
  <countNotBuiltBuilds>true</countNotBuiltBuilds>
  <countAbortedBuilds>true</countAbortedBuilds>
</org.jenkinsci.plugins.prometheus.config.PrometheusConfiguration>

Now what else we would need? @fche I think you mention that we could do something with this but some changes would also be required because of OSIO infrastructure. Can we discuss in this issue what else it is required?

CC/ @chmouel @krishnapaparaju @pradeepto

Related with: openshiftio/openshift.io#2778

[pradeepto]

@lordofthejars If you are working on this, assign it to yourself and put this on the sprint board. Thanks.

[lordofthejars]

@pradeepto if I have rights I would do it :) But I have no idea why in all f8 projects I cannot assign myself

[chmouel]

@lordofthejars just invited you to this org,

[fche]

Does this mechanism expose the prometheus metrics to unauthenticated localhost (so we'd need the oso-tenant prometheus-relay code in the pod to get at it)? Does it expose them to authenticated routed external URL (so we'd need a user token to get at it)?

[lordofthejars]

@fche I am not sure if it is exposed to external URLs. I think that if jenkins server endpoints are available outside localhost, then this Prometheus endpoint is external as well.