Trigger

Trigger a flow on periodic message consumption from MQTT topics.

Note that you don't need an extra task to consume the message from the event trigger. The trigger will automatically consume messages and you can retrieve their content in your flow using the {{ trigger.uri }} variable. If you would like to consume each message from MQTT topics in real-time and create one execution per message, you can use the io.kestra.plugin.mqtt.RealtimeTrigger instead.

yaml
type: "io.kestra.plugin.mqtt.Trigger"

Examples

yaml
id: mqtt_trigger
namespace: company.team

tasks:
  - id: log
    type: io.kestra.plugin.core.log.Log
    message: "{{ trigger.payload }}"

triggers:
  - id: trigger
    type: io.kestra.plugin.mqtt.Trigger
    server: tcp://localhost:1883
    clientId: kestraProducer
    topic:
      - kestra/sensors/cpu
      - kestra/sensors/mem
    serdeType: JSON
    maxRecords: 10

Properties

topic *object

Topic where to consume message

Can be a string or a List of string to consume from multiple topic

authMethod string

clientId string

conditions array

List of conditions in order to limit the flow trigger.

connectionTimeout string

Format duration

crt string

httpsHostnameVerificationEnabled booleanstring

interval string

Default PT1M

Format duration

Interval between polling.

The interval between 2 different polls of schedule, this can avoid to overload the remote system with too many calls. For most of the triggers that depend on external systems, a minimal interval must be at least PT30S. See ISO_8601 Durations for more information of available interval values.

maxDuration string

Format duration

The max duration waiting for new rows

It's not an hard limit and is evaluated every second

maxRecords integerstring

The max number of rows to fetch before stopping

It's not an hard limit and is evaluated every second

mqttVersion string

Default V5

Possible Values

V3V5

password string

qos integerstring

Default 1

Sets the quality of service for this message.

Quality of Service 0: indicates that a message should be delivered at most once (zero or one times). The message will not be persisted to disk, and will not be acknowledged across the network. This QoS is the fastest, but should only be used for messages which are not valuable - note that if the server cannot process the message (for example, there is an authorization problem). Also known as "fire and forget".
Quality of Service 1: indicates that a message should be delivered at least once (one or more times). The message can only be delivered safely if it can be persisted, so the application must supply a means of persistence using MqttConnectOptions. If a persistence mechanism is not specified, the message will not be delivered in the event of a client failure. The message will be acknowledged across the network.
Quality of Service 2: indicates that a message should be delivered once. The message will be persisted to disk, and will be subject to a two-phase acknowledgement across the network. The message can only be delivered safely if it can be persisted, so the application must supply a means of persistence using MqttConnectOptions. If a persistence mechanism is not specified, the message will not be delivered in the event of a client failure. If persistence is not configured, QoS 1 and 2 messages will still be delivered in the event of a network or server problem as the client will hold state in memory. If the MQTT client is shutdown or fails and persistence is not configured then delivery of QoS 1 and 2 messages can not be maintained as client-side state will be lost.

serdeType string

Default JSON

Possible Values

STRINGJSONBYTES

Serializer / Deserializer used for the payload

server string

stopAfter array

SubType string

Possible Values

CREATEDRUNNINGPAUSEDRESTARTEDKILLINGSUCCESSWARNINGFAILEDKILLEDCANCELLEDQUEUEDRETRYINGRETRIEDSKIPPEDBREAKPOINT

List of execution states after which a trigger should be stopped (a.k.a. disabled).

username string

Outputs

messagesCount integer

Number of message produced

uri string

Format uri

URI of a kestra internal storage file

Definitions

io.kestra.core.models.triggers.TimeWindow

deadline string

Format partial-time

SLA daily deadline

Use it only for DAILY_TIME_DEADLINE SLA.

endTime string

Format partial-time

SLA daily end time

Use it only for DAILY_TIME_WINDOW SLA.

startTime string

Format partial-time

SLA daily start time

Use it only for DAILY_TIME_WINDOW SLA.

type string

Default DURATION_WINDOW

Possible Values

DAILY_TIME_DEADLINEDAILY_TIME_WINDOWDURATION_WINDOWSLIDING_WINDOW

The type of the SLA

The default SLA is a sliding window (DURATION_WINDOW) with a window of 24 hours.

window string

Format duration

The duration of the window

Use it only for DURATION_WINDOW or SLIDING_WINDOW SLA. See ISO_8601 Durations for more information of available duration value. The start of the window is always based on midnight except if you set windowAdvance parameter. Eg if you have a 10 minutes (PT10M) window, the first window will be 00: 00 to 00: 10 and a new window will be started each 10 minutes

windowAdvance string

Format duration

The window advance duration

Use it only for DURATION_WINDOW SLA. Allow to specify the start time of the window Eg: you want a window of 6 hours (window=PT6H), by default the check will be done between: 00: 00 and 06: 00, 06: 00 and 12: 00, 12: 00 and 18: 00, and 18: 00 and 00: 00. If you want to check the window between 03: 00 and 09: 00, 09: 00 and 15: 00, 15: 00 and 21: 00, and 21: 00 and 3: 00, you will have to shift the window of 3 hours by settings windowAdvance: PT3H

Condition for a specific flow of an execution.

flowId *string

The flow id.

namespace *string

The namespace of the flow.

type *object

Condition for a flow namespace.

namespace *string

The namespace of the flow or the prefix if prefix is true.

type *object

prefix boolean

Default false

If we must look at the flow namespace by prefix (checked using startWith). The prefix is case sensitive.

Condition for a specific flow. Note that this condition is deprecated, use `io.kestra.plugin.core.condition.ExecutionFlow` instead.

flowId *string

The flow id.

namespace *string

The namespace of the flow.

type *object

Condition to allow events between two specific times.

type *object

after string

Format time

The time to test must be after this one.

Must be a valid ISO 8601 time with offset.

before string

Format time

The time to test must be before this one.

Must be a valid ISO 8601 time with offset.

date string

Default {{ trigger.date }}

The time to test.

Can be any variable or any valid ISO 8601 time. By default, it will use the trigger date.

Condition that check labels of an execution.

labels *arrayobject

List of labels to match in the execution.

type *object

Condition based on the outputs of an upstream execution.

expression *string

type *object

Condition to allow events on weekend.

type *object

date string

Default {{ trigger.date }}

The date to test.

Can be any variable or any valid ISO 8601 datetime. By default, it will use the trigger date.

Condition to have at least one condition validated.

conditions *array

Min items 1

The list of conditions to validate.

If any condition is true, it will allow the event's execution.

type *object

Condition for an execution namespace.

namespace *string

String against which to match the execution namespace depending on the provided comparison.

type *object

comparison string

Possible Values

EQUALSPREFIXSUFFIX

Comparison to use when checking if namespace matches. If not provided, it will use EQUALS by default.

prefix booleanstring

Default false

Whether to look at the flow namespace by prefix. Shortcut for comparison: PREFIX.

Only used when comparison is not set

Run a flow if the list of preconditions are met in a time window.

conditions *object

SubType

The list of preconditions to wait for

The key must be unique for a trigger because it will be used to store the previous evaluation result.

id *string

Validation RegExp ^[a-zA-Z0-9][a-zA-Z0-9_-]*

Min length 1

A unique id for the condition

type *object

resetOnSuccess boolean

Default true

Whether to reset the evaluation results of SLA conditions after a first successful evaluation within the given time period.

By default, after a successful evaluation of the set of SLA conditions, the evaluation result is reset, so, the same set of conditions needs to be successfully evaluated again in the same time period to trigger a new execution. This means that to create multiple executions, the same set of conditions needs to be evaluated to true multiple times. You can disable this by setting this property to false so that, within the same period, each time one of the conditions is satisfied again after a successful evaluation, it will trigger a new execution.

timeWindow TimeWindow

Default

{
  "type": "DURATION_WINDOW"
}

Define the time period (or window) for evaluating preconditions.

You can set the type of sla to one of the following values:

DURATION_WINDOW: this is the default type. It uses a start time (windowAdvance) and end time (window) that are moving forward to the next interval whenever the evaluation time reaches the end time, based on the defined duration window. For example, with a 1-day window (the default option: window: PT1D), the SLA conditions are always evaluated during 24h starting at midnight (i.e. at time 00: 00: 00) each day. If you set windowAdvance: PT6H, the window will start at 6 AM each day. If you set windowAdvance: PT6H and you also override the window property to PT6H, the window will start at 6 AM and last for 6 hours — as a result, Kestra will check the SLA conditions during the following time periods: 06: 00 to 12: 00, 12: 00 to 18: 00, 18: 00 to 00: 00, and 00: 00 to 06: 00, and so on.
SLIDING_WINDOW: this option also evaluates SLA conditions over a fixed time window, but it always goes backward from the current time. For example, a sliding window of 1 hour (window: PT1H) will evaluate executions for the past hour (so between now and one hour before now). It uses a default window of 1 day.
DAILY_TIME_DEADLINE: this option declares that some SLA conditions should be met "before a specific time in a day". With the string property deadline, you can configure a daily cutoff for checking conditions. For example, deadline: "09: 00: 00" means that the defined SLA conditions should be met from midnight until 9 AM each day; otherwise, the flow will not be triggered.
DAILY_TIME_WINDOW: this option declares that some SLA conditions should be met "within a given time range in a day". For example, a window from startTime: "06: 00: 00" to endTime: "09: 00: 00" evaluates executions within that interval each day. This option is particularly useful for declarative definition of freshness conditions when building data pipelines. For example, if you only need one successful execution within a given time range to guarantee that some data has been successfully refreshed in order for you to proceed with the next steps of your pipeline, this option can be more useful than a strict DAG-based approach. Usually, each failure in your flow would block the entire pipeline, whereas with this option, you can proceed with the next steps of the pipeline as soon as the data is successfully refreshed at least once within the given time range.

Condition to exclude others conditions.

conditions *array

Min items 1

The list of conditions to exclude.

If any conditions is true, it will prevent the event's execution.

type *object

Condition to execute tasks on a specific day of the week relative to the current month (first, last, ...)

dayInMonth *string

Possible Values

FIRSTLASTSECONDTHIRDFOURTH

Are you looking for the first or the last day in the month?

dayOfWeek *string

Possible Values

MONDAYTUESDAYWEDNESDAYTHURSDAYFRIDAYSATURDAYSUNDAY

The day of week.

type *object

date string

Default {{ trigger.date }}

The date to test.

Can be any variable or any valid ISO 8601 datetime. By default, it will use the trigger date.

Condition based on variable expression.

expression *string

type *object

Condition to allow events on a particular day of the week.

dayOfWeek *string

Possible Values

MONDAYTUESDAYWEDNESDAYTHURSDAYFRIDAYSATURDAYSUNDAY

The day of week.

type *object

date string

Default {{ trigger.date }}

The date to test.

Can be any variable or any valid ISO 8601 datetime. By default, it will use the trigger date.

Condition based on execution status.

type *object

in array

SubType string

Possible Values

CREATEDRUNNINGPAUSEDRESTARTEDKILLINGSUCCESSWARNINGFAILEDKILLEDCANCELLEDQUEUEDRETRYINGRETRIEDSKIPPEDBREAKPOINT

List of states that are authorized.

notIn array

SubType string

Possible Values

CREATEDRUNNINGPAUSEDRESTARTEDKILLINGSUCCESSWARNINGFAILEDKILLEDCANCELLEDQUEUEDRETRYINGRETRIEDSKIPPEDBREAKPOINT

List of states that aren't authorized.

Condition to allow events between two specific datetime values.

type *object

after string

Format date-time

The date to test must be after this one.

Must be a valid ISO 8601 datetime with the zone identifier (use 'Z' for the default zone identifier).

before string

Format date-time

The date to test must be before this one.

Must be a valid ISO 8601 datetime with the zone identifier (use 'Z' for the default zone identifier).

date string

Default {{ trigger.date }}

The date to test.

Can be any variable or any valid ISO 8601 datetime. By default, it will use the trigger date.

Condition that matches if any taskRun has retry attempts.

type *object

in array

SubType string

Possible Values

CREATEDRUNNINGPAUSEDRESTARTEDKILLINGSUCCESSWARNINGFAILEDKILLEDCANCELLEDQUEUEDRETRYINGRETRIEDSKIPPEDBREAKPOINT

List of states that are authorized.

notIn array

SubType string

Possible Values

CREATEDRUNNINGPAUSEDRESTARTEDKILLINGSUCCESSWARNINGFAILEDKILLEDCANCELLEDQUEUEDRETRYINGRETRIEDSKIPPEDBREAKPOINT

List of states that aren't authorized.

Condition to allow events on public holidays.

type *object

country string

ISO 3166-1 alpha-2 country code. If not set, it uses the country code from the default locale.

It uses the Jollyday library for public holiday calendar that supports more than 70 countries.

date string

Default {{ trigger.date }}

The date to test.

Can be any variable or any valid ISO 8601 datetime. By default, it will use the trigger date.

subDivision string

ISO 3166-2 country subdivision (e.g., provinces and states) code.

It uses the Jollyday library for public holiday calendar that supports more than 70 countries.

​Trigger

Trigger