Ansible role prometheus ping exporter

Ansible role to install the prometheus node exporter from github.com/czerwonk/ping_exporte

Some variables

value	default
ping_exporter__user	`ping_exporter`
ping_exporter__group	`ping_exporter`
ping_exporter__user_home	`/var/lib/ping_exporter`
ping_exporter__shell	`/bin/false`
ping_exporter__version	`latest`
ping_exporter__targets	`[]`
ping_exporter__nameserver	`9.9.9.9`
ping_exporter__web_listen_address	`:9427`
submodules_versioncheck	`false`