Load directory service

File-based definitions of tasks, templates, and load handlers

The load directory service enables file-based definitions of Kapacitor tasks, templates, and topic handlers that are loaded on startup or when a NOHUP signal is sent to the process.

Configuration

The load directory service configuration is specified in the [load] section of the Kapacitor configuration file.

[load]
 enabled = true
 dir="/path/to/directory"

dir specifies the directory where the definition files are located.

The service will attempt to load the definitions from three subdirectories.

The tasks directory should contain task TICKscripts and the associated templated task definition files (either YAML or JSON).

The templates directory should contain templated TICKscripts.

The handlers directory will contain topic handler definitions in yaml or json.

Tasks

Task files must be placed in the tasks subdirectory of the load service directory. Task TICKscripts are specified based on the following scheme:

  • id - the file name without the .tick extension
  • type - determined by introspection of the task (stream or batch)
  • dbrp - defined using the dbrp keyword followed by a specified database and retention policy

In the following example, the TICKscript will create a stream task named my_task for the dbrp telegraf.autogen.

// /path/to/directory/tasks/my_task.tick
dbrp "telegraf"."autogen"

stream
    |from()
        .measurement('cpu')
        .groupBy(*)
    |alert()
        .warn(lambda: "usage_idle" < 20)
        .crit(lambda: "usage_idle" < 10)
        // Send alerts to the `cpu` topic
        .topic('cpu')

Task templates

Template files must be placed in the templates subdirectory of the load service directory. Task templates are defined according to the following scheme:

  • id - the file name without the tick extension
  • type - determined by introspection of the task (stream or batch)
  • dbrp - defined using the dbrp keyword followed by a specified database and retention policy

The following TICKscript example will create a stream template named my_template for the dbrp telegaf.autogen.

// /path/to/directory/templates/my_template.tick
dbrp "telegraf"."autogen"

var measurement string
var where_filter = lambda: TRUE
var groups = [*]
var field string
var warn lambda
var crit lambda
var window = 5m
var slack_channel = '#alerts'

stream
    |from()
        .measurement(measurement)
        .where(where_filter)
        .groupBy(groups)
    |window()
        .period(window)
        .every(window)
    |mean(field)
    |alert()
         .warn(warn)
         .crit(crit)
         .slack()
         .channel(slack_channel)

Templated tasks

Templated task files must be placed in the tasks subdirectory of the load service directory. Templated tasks are defined according to the following scheme:

  • id - filename without the yaml, yml, or json extension
  • dbrps - required if not specified in template
  • template-id - required
  • vars - list of template vars

In this example, the templated task YAML file creates a stream task, named my_templated_task, for the dbrp telegraf.autogen.

# /path/to/directory/tasks/my_templated_task.tick
dbrps:
  - { db: "telegraf", rp: "autogen"}
template-id: my_template
vars:
  measurement:
   type: string
   value: cpu
  where_filter:
   type: lambda
   value: "\"cpu\" == 'cpu-total'"
  groups:
   type: list
   value:
       - type: string
         value: host
       - type: string
         value: dc
  field:
   type: string
   value : usage_idle
  warn:
   type: lambda
   value: "\"mean\" < 30.0"
  crit:
   type: lambda
   value: "\"mean\" < 10.0"
  window:
   type: duration
   value : 1m
  slack_channel:
   type: string
   value: "#alerts_testing"

The same task can also be created using JSON, as in this example:

{
  "dbrps": [{"db": "telegraf", "rp": "autogen"}],
  "template-id": "my_template",
  "vars": {
    "measurement": {"type" : "string", "value" : "cpu" },
    "where_filter": {"type": "lambda", "value": "\"cpu\" == 'cpu-total'"},
    "groups": {"type": "list", "value": [{"type":"string", "value":"host"},{"type":"string", "value":"dc"}]},
    "field": {"type" : "string", "value" : "usage_idle" },
    "warn": {"type" : "lambda", "value" : "\"mean\" < 30.0" },
    "crit": {"type" : "lambda", "value" : "\"mean\" < 10.0" },
    "window": {"type" : "duration", "value" : "1m" },
    "slack_channel": {"type" : "string", "value" : "#alerts_testing" }
  }
}

Topic handlers

Topic handler files must be placed in the handlers subdirectory of the load service directory.

id: handler-id
topic: cpu
kind: slack
match: changed() == TRUE
options:
  channel: '#alerts'

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