3.10.0 introduced a new health-check management component which can be used to either report the overall status of all known adapters in that JVM or to report on a specific workflow/channel; reporting on a specific workflow/channel means that you must know what the unique IDs will be. What it doesn’t do is to filter by status so you can’t get a list of all the channels that aren’t started. However, you can still get the output you need if wrangle the JSON output using JQ.

First of all, you’ll need to install jq for your desired platform. You can get it however you normally install packages on your platform (scoop.sh / apt-get / homebrew etc.).

For our purposes, we have an Interlok instance that’s been built with the health-check management component enabled. We’re running the latest SNAPSHOT artefact: 3.10.1 will change the existing top level json object from java.util.Collection to adapters to avoid excessive information disclosure.

managementComponents=jmx:jetty:health-check
rest.health-check.path=/health/*

The Interlok instance itself has 3 channels; 2 of which are started; 1 is not. When you use curl against the health check URL then it returns 200 OK along with the status of the adapter.

$ curl -si http://localhost:8080/health
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
Server: Jetty(9.4.28.v20200408)

{"adapters":[{"adapter-state":{"id":"MyInterlokInstance","state":"StartedState","channel-states":[{"channel-state":[{"id":"jetty1","state":"StartedState","workflow-states":[{"workflow-state":{"id":"jetty-workflow","state":"StartedState"}}]},{"id":"jetty2(not-started)","state":"ClosedState","workflow-states":[{"workflow-state":{"id":"jetty-workflow","state":"ClosedState"}}]},{"id":"jetty3","state":"StartedState","workflow-states":[{"workflow-state":{"id":"jetty-workflow","state":"StartedState"}}]}]}]}}]}

What we really want is to just have a JSON array of channels, with their status. We will arbitrarily filter the array based on the state (using the jq select function), so we either print out those that are started, or those that aren’t started.

$ curl -s http://localhost:8080/health | jq -c '.["adapters"][0] | .["adapter-state"] | .["channel-states"][] | .["channel-state"][] | select (.state == "StartedState") | { (.id): .state }' | jq -s -c '.'
[{"jetty1":"StartedState"},{"jetty3":"StartedState"}]

$ curl -s http://localhost:8080/health | jq -c '.["adapters"][0] | .["adapter-state"] | .["channel-states"][] | .["channel-state"][] | select (.state != "StartedState") | { (.id): .state }' | jq -s -c '.'
[{"jetty2(not-started)":"ClosedState"}]