Very simple staticly defined sensu proxy check using ping command.
source attribute value be used in the check result to replace the client name.
replace <<HOST>> with hostname want

{
  "checks": {
    "ping-<<HOST>>": {
      "command": "ping <<HOST>>",
      "subscribers": [
        "ping-proxy"
      ],
      "interval": 60,
      "source": "<<HOST>>",
    }
  }
}