This node offers health checks for flow(s) running in a containerized environment.

When added to a flow, this node will start an HTTP server, listening on the defined port providing three paths: /started, /ready and /alive.
It let's you define conditions that must be fulfilled in order to let one or more probes succeed.

Please note that only one health checks node can be defined within ALL flows and subflows!

Integration

This node offers three paths: /started, /ready and /alive at a configured port.
These paths can be used as HTTP probes in a containerized environment.
Each of the paths will check for one or more of the defined conditions and return a 200 OK or 500 Internal Error if at least one of the conditions is not fulfilled. Additionally, the body will list the condition(s) that failed.

Example

Let's think about a flow, subscribing to an MQTT message broker (using an mqtt in node).
A health checks node will then define a condition, named for example 'MQTT connected' and add this condition to all 3 probes.
A watchdog will check for the mqtt in node's status (one of 'connected', 'connecting' or 'disconnected') and its color ("green" if connected) in particular. On a status change (triggered by a status node), the health checks node's condition will be set accordingly using a switch node: Condition fulfilled if the color is "green", not fulfilled otherwise.
Eventually, the container framework will frequently call the container's HTTP probes and decide what to do, if a check fails.
An appropriate example flow can be found in the Editor (via Menu->Import->Examples->@hypertegrity/node-red-contrib-k8s-helper).