Have a setting to enable/disable instrumentation

[ivantopo]

One thing that keeps coming up again and again is the need to enable/disable instrumentation via configuration alone, without fiddling with SBT plugins or selectively calling Kamon.init(). Something as simple as having a kanela.enabled setting should be enough.

[JR-Utily]

If the Kamon.init() is guarded by a variable from application.conf, would this work ?
Or would the call to read application.conf be already too much regarding Kamon.init() to be the real first instruction of the application ?

[JR-Utily]

Something like:

object Start extends App {
  val config = ConfigFactory.load()
  if (config.getBoolean("kanela.enabled") {  Kamon.init() }

  // Your application code goes here
}

[ivantopo]

This is now being solved with these two PRs:

• implement a kamon.enabled setting Kamon#1243
• add a new disable method on Kanela #146