DocsWorkflow ComponentsTriggersFlow Trigger

Flow Trigger​Flow ​Trigger

Trigger flows from another flow execution.

Flow triggers allows you to trigger a flow after another flow execution, enabling event-driven patterns.

yaml
type: "io.kestra.plugin.core.trigger.Flow"

Kestra is able to trigger one flow after another one. This allows the chaining of flows without the need to update the base flows. With this capacity, you can break responsibility between different flows to different teams.

Check the Flow trigger documentation for the list of all properties.

Conditions

You can provide conditions to determine when your Flow should be executed. Along with the core trigger conditions, you can use the following:

Example

This flow will be triggered after each successful execution of the flow io.kestra.tests.trigger-flow and forward the uri output of the my-task task.

yaml
id: trigger_flow_listener
namespace: company.team

inputs:
  - id: fromParent
    type: STRING

tasks:
  - id: onlyNoInput
    type: io.kestra.plugin.core.debug.Return
    format: "v1: {{ trigger.executionId }}"

triggers:
  - id: listenFlow
    type: io.kestra.plugin.core.trigger.Flow
    inputs:
      fromParent: '{{ outputs.myTask.uri }}'
    conditions:
      - type: io.kestra.plugin.core.condition.ExecutionFlowCondition
        namespace: company.team
        flowId: trigger_flow
      - type: io.kestra.plugin.core.condition.ExecutionStatusCondition
        in:
          - SUCCESS

Parent flow:

yaml
id: trigger_flow
namespace: company.team

tasks:
  - id: myTask
    type: io.kestra.plugin.core.http.Download
    uri: https://dummyjson.com/products

This flow will be triggered after the successful execution of both flows flow-a and flow-b during the current day. When the conditions are met, the counter is reset and can be re-triggered during the same day. See MultipleCondition for more details

yaml
id: trigger-multiplecondition-listener
namespace: company.team

tasks:
  - id: onlyListener
    type: io.kestra.plugin.core.debug.Return
    format: "let's go "

triggers:
  - id: multipleListenFlow
    type: io.kestra.plugin.core.trigger.Flow
    conditions:
      - id: multiple
        type: io.kestra.plugin.core.condition.MultipleCondition
        window: P1D
        windowAdvance: P0D
        conditions:
          flow-a:
            type: io.kestra.plugin.core.condition.ExecutionFlowCondition
            namespace: company.team
            flowId: trigger-multiplecondition-flow-a
          flow-b:
            type: io.kestra.plugin.core.condition.ExecutionFlowCondition
            namespace: company.team
            flowId: trigger-multiplecondition-flow-b

Simply execute the two flows below to trigger trigger-multiplecondition-listener:

yaml
id: trigger-multiplecondition-flow-a
namespace: company.team

tasks:
  - id: hello
    type: io.kestra.plugin.core.log.Log
    message: Trigger A
yaml
id: trigger-multiplecondition-flow-b
namespace: company.team

tasks:
  - id: hello
    type: io.kestra.plugin.core.log.Log
    message: Trigger B

Example: Alerting

In this example, the Flow Trigger conditions are set to execute the flow when any workflow execution has a warning or failed status. We can configure this flow to send a notification to Slack (or any other platform) with information around the failure. Using this pattern, you can manage alerts on failure all in one place.

yaml
id: failure_alert_slack
namespace: system

tasks:
  - id: send_alert
    type: io.kestra.plugin.notifications.slack.SlackExecution
    url: "{{ secret('SLACK_WEBHOOK') }}"
    channel: "#general"
    executionId: "{{ trigger.executionId }}"

triggers:
  - id: on_failure
    type: io.kestra.plugin.core.trigger.Flow
    conditions:
      - type: io.kestra.plugin.core.condition.ExecutionStatusCondition
        in:
          - FAILED
          - WARNING

Check out the Blueprint here.

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