Internal services

HTTP, TCP, DNS, and ping checks can run from an agent that reaches a private target. Update the agent before assigning ping checks or HTTP request headers to it.

Add a check in the panel

1. Open the service’s page and click Add check.
2. Enter the private target and choose the agent’s host under Run from.
3. Save. The agent receives the check without a restart.

For a discovered target, use Monitor on the host’s page; see Discovery.

Add a check in kogut.toml

1. List the agent’s host in a service’s hosts.
2. Set the check’s from to that host’s name in kogut, not necessarily its OS hostname.

[[service]]
name = "postgres"
hosts = ["db-1"]

[[check]]
name = "Postgres port"
service = "postgres"
tcp = "127.0.0.1:5432"
from = "db-1"

The file is rejected if no service lists the from host. See the check reference and Recipes.

Choose where to probe

• The target’s own host and 127.0.0.1 test whether the service answers locally.
• Another host in the private network tests the path other services use.
• Each check runs from one place, so public and private access need separate checks.

For a container’s published port, run the agent with network_mode: host and use the host port, such as 127.0.0.1:8080 (Docker).

Handle an offline agent

If the agent sends nothing for two minutes, its checks become unknown, not down, and the silence opens a host incident. After a server restart, agents have two minutes to reconnect, and send buffered results with their original timestamps. The public status page does not show internal targets.