DOCSTUTORIALTRIGGERS

​Triggers

You use triggers to start a flow. They can be scheduled or triggered by an event. Kestra core provides three types of triggers:

  • Schedule
    • Trigger your flow based on a cron expression
  • Flow trigger
    • Trigger your flow based on another flow end
  • Webhook
    • Trigger your flow based on an HTTP request

Many other triggers are available from the plugins, such as triggers based on file creation or a message queue.

Defining triggers

The Trigger definition is close to the task definition. We define them in the triggers section of the flow. And as a Task, it contains an id, a type, and some properties related to his type. A Flow can have multiple Triggers.

The below triggers will start the flow every day at 10 am or when the trigger-flow flow ends.

yaml
triggers:
  - id: schedule
    type: io.kestra.core.models.triggers.types.Schedule
    cron: 0 10 * * *
  - id: listenFlow
    type: io.kestra.core.models.triggers.types.Flow
    conditions:
      - type: io.kestra.core.models.conditions.types.ExecutionFlowCondition
        namespace: io.kestra.tutorial
        flowId: trigger-flow

Add a trigger to your flow

Let's schedule our flow. This trigger will start our flow every Monday at 10 am.

yaml
triggers:
  - id: schedule
    type: io.kestra.core.models.triggers.types.Schedule
    cron: 0 10 * * 1
Click here to see the full flow
yaml
id: kestra-tutorial
namespace: io.kestra.tutorial
labels:
  env: PRD
description: |
  # Kestra Tutorial
  As you notice, we can use markdown here.
tasks:
  - id: download
    type: io.kestra.plugin.fs.http.Download
    uri: "https://gist.githubusercontent.com/tchiotludo/2b7f28f4f507074e60150aedb028e074/raw/6b6348c4f912e79e3ffccaf944fd019bf51cba30/conso-elec-gaz-annuelle-par-naf-agregee-region.csv"
  - id: analyze-data
    type: io.kestra.core.tasks.scripts.Python
    runner: DOCKER
    dockerOptions:
      image: python
    inputFiles:
      data.csv: "{{outputs.download.uri}}"
      main.py: |
        import pandas as pd
        from kestra import Kestra
        data = pd.read_csv("data.csv", sep=";")
        data.info()
        sumOfConsumption = data['conso'].sum()
        Kestra.outputs({'sumOfConsumption': int(sumOfConsumption)})
    requirements:
      - pandas
triggers:
  - id: schedule
    type: io.kestra.core.models.triggers.types.Schedule
    cron: 0 10 * * *

Now, let's dive into how to create complex workflows through flowable.