Skip to main content

​
Description

The connection probe reads the host connection table (never opens new connections) and counts entries matching configured filters. Supports filtering by process, endpoint, protocol, and state.

​
Config fields

FieldTypeRequiredDefaultDescription
typestringYes—Must be "connection"
namestringYes—Probe identifier (used in messages and logs)
descriptionstringNo—Purpose description
processNamestringNo—Filter by process name. Needs CAP_SYS_PTRACE on Linux
processPathstringNo—Filter by executable path. Needs CAP_SYS_PTRACE on Linux
localAddressstringNo—Filter by local IP address
localPortintNo—Filter by local port
remoteAddressstringNo—Filter by remote IP address
remotePortintNo—Filter by remote port
protocolstringNo—Filter by protocol: "tcp" or "udp"
statesstring[]No—Filter by connection state (e.g. ["ESTABLISHED", "LISTEN"])
minCountintNo1Minimum connection count. Below → down
maxCountintNo—Maximum connection count. Above → warning

​
Metrics

MetricTypeDescription
vms.connection.statusstatusup, down, or warning
vms.connection.countgaugeNumber of matching connections
vms.agent.permission_missinggaugeEmitted when processName/processPath is configured but CAP_SYS_PTRACE is missing

​
Example config

{
  "type": "connection",
  "name": "nginx-to-postgres",
  "processName": "nginx",
  "remotePort": 5432,
  "states": ["ESTABLISHED"],
  "minCount": 1
}

​
Notes

  • The probe does not open new connections — it only reads the existing host connection table.
  • All filters use AND logic — a connection must match all configured filters.
  • Missing CAP_SYS_PTRACE with process filters results in 0 matches and emits vms.agent.permission_missing.