http availability check with Prometheus [closed]
Update: There's now an official blackbox exporter https://github.com/prometheus/blackbox_exporter
There's an blackbox prober for Prometheus that'll let you do this: https://github.com/discordianfish/blackbox_prober
Prometheus is mainly focused on whitebox rather than blackbox monitoring, but over time it's likely this functionality will be added as a core component.
See http://prometheus.io/docs/instrumenting/exporters/ for a full list of the current exporters.