Reloading configuration via HTTP-POST fails but returns 200

[anthraxn8b]

What did you do?

1. I intentionally provided a bad config file!
2. Reload configuration via POST on "http://myhostname:9093/-/reload".

What did you expect to see?

An HTTP-400 return code.

What did you see instead? Under which circumstances?

An HTTP-200 return code:

Response (0.054s)
200 OK
HEADER:

• Date: Wed, 20 Dec 2017 08:04:18 GMT
• Content-Length: 31
• Content-Type: text/plain; charset=utf-8

CONTENT:
"Reloading configuration file..."

Environment

• System information:

  Docker image "prom/alertmanager:v0.11.0"
  Linux 3.10.0-514.6.1.el7.x86_64 x86_64

• Alertmanager version:

  alertmanager, version 0.11.0 (branch: HEAD, revision: 30dd042)
  build user: root@3e103e3fc918
  build date: 20171116-17:43:56
  go version: go1.9.2

• Prometheus version:

  NOT REQUIRED FOR THIS BUG

• Alertmanager configuration file:

  NOT REQUIRED FOR THIS BUG

• Prometheus configuration file:

  NOT REQUIRED FOR THIS BUG

• Logs:

level=info ts=2017-12-20T08:04:18.396762583Z caller=main.go:293 msg="Loading configuration file" file=/etc/alertmanager/config.yml
level=error ts=2017-12-20T08:04:18.397019223Z caller=main.go:296 msg="Loading configuration file failed" file=/etc/alertmanager/config.yml err="unknown fields in global: opsgenie_api_host, hipchat_url"