Hints based autodiscover

Heartbeat supports autodiscover based on hints from the both Docker and Kubernetes. The hints system looks for hints in Kubernetes Pod annotations or Docker labels that have the prefix co.elastic.monitor. As soon as the container starts, Heartbeat will check if it contains any hints and launch the proper config for it. Hints tell Heartbeat how to get logs for the given container.

Hints for Heartbeat take the form co.elastic.monitor/MONITOR_INDEX.CONFIG_OPTION=VALUE, where MONITOR_INDEX represents the index of monitor, and CONFIG_OPTION is any of the Set up monitors options, with VALUE being the value you’d like to set that option to.

As an example let’s convert the regular syntax Heartbeat monitors below into autodiscover hints.

-- heartbeat.monitors:
- type: tcp
  hosts: '${data.host}:6379'
  schedule: @every 10s
- type: icmp
  hosts: '${data.host}'
  schedule: @every 10s

To configure this with autodiscover, add the following line to your Dockerfile to add the requisite labels.

LABEL co.elastic.monitor/1.type=tcp co.elastic.monitor/1.hosts='${data.host}:6379' co.elastic.monitor/1.schedule='@every 10s'
LABEL co.elastic.monitor/2.type=icmp co.elastic.monitor/2.hosts='${data.host}' co.elastic.monitor/2.schedule='@every 10s'

Then, add the following to heartbeat.yml:

heartbeat.autodiscover:
  providers:
  - type: docker
    hints.enabled: true

Then, start Heartbeat. This should discover the container you built and ping it once with ICMP, another time with TCP.

For a full list of variables available, see the provider-specific docs in Autodiscover.