Added /-/reload endpoint for Prometheus and Alertmanager...

Added /-/reload endpoint for Prometheus and Alertmanager https://github.com/prometheus/alertmanager/issues/353 (#647)

Prometheus code ref.: https://github.com/prometheus/prometheus/blob/master/web/web.go#L208

content/docs/alerting/configuration.md

@@ -19,7 +19,8 @@ To view all available command-line flags, run `alertmanager -h`.
 
 Alertmanager can reload its configuration at runtime. If the new configuration
 is not well-formed, the changes will not be applied and an error is logged.
-A configuration reload is triggered by sending a `SIGHUP` to the process.
+A configuration reload is triggered by sending a `SIGHUP` to the process or
+sending a HTTP POST request to the `/-/reload` endpoint.
 
 ## Configuration file
 

content/docs/operating/configuration.md

@@ -17,7 +17,8 @@ To view all available command-line flags, run `prometheus -h`.
 
 Prometheus can reload its configuration at runtime. If the new configuration
 is not well-formed, the changes will not be applied.
-A configuration reload is triggered by sending a `SIGHUP` to the Prometheus process.
+A configuration reload is triggered by sending a `SIGHUP` to the Prometheus process or 
+sending a HTTP POST request to the `/-/reload` endpoint.
 This will also reload any configured rule files.