Document headers and ssl for metricsets

[ruflin]

In #3945 customer headers, auth and ssl was introduced for all http metricsets. The following must be done:

• Add documentation for it
• Add it to the full config

Potentially also find a way on how to test it.

[joegallo]

One quick things that's not 100% clear to me:

For elasticsearch.output, I would specify:

    hosts: ["somehost"]
    username: "someusername"
    password: "somepassword"
    headers:
      SomeHeader: SomeValue

But it looks like perhaps the username and password auth for metricsets has been implemented purely as additional headers only? So no username/password -- just have to gen up an Authorization header myself. Is that correct or did I misunderstand?

If I did understand correctly, I guess this comment in then an enhancement request to handle username and passwords specially. (That might be pie in the sky, though, but it doesn't hurt to ask. :D)

[ruflin]

@joegallo Sorry for the late reply. The above change does not include username / password. But you can pass username/password as part of the host and it will be automatically extracted to create the correct headers and will also not be logged.

+1 on having also general support for the fields username and password as part of http. Could you open a feature request for this?