Offer metrics for Prometheus

Feature

• The Controller and Agents offer metrics for Prometheus.
  • The /metrics endpoint is available and provides information about
    • JVM metrics such as heap space, garbage collecting etc.
    • product metrics such as orders in processing, journal usage etc.
• Use of the /metrics endpoint requires the ReadMetrics permission in the private.conf file:

  js7 {
      auth {
          users {
              Prometheus {
                  permissions = [ ReadMetrics ]
                  # distinguished-names = [
                  #     "DNQ=SOS CA, CN=prometheus.sos, OU=IT, O=SOS, L=Berlin, ST=Berlin, C=DE"
                  # ]
                  password="plain:secret"            }
          }
      }
  }