You can launch a task from a stream by using one of the available task-launcher sinks. Currently the only available
task-launcher sink is the task-launcher-local which will launch a task on your local machine.
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A task-launcher sink expects a message containing a TaskLaunchRequest object in its payload. From the
TaskLaunchRequest object the task-launcher will obtain the URI of the artifact to be launched as well as the
properties and command line arguments to be used by the task.
The task-launcher-local can be added to the available sinks by executing the app register command as follows:
app register --name task-launcher-local --type sink --uri maven://org.springframework.cloud.stream.app:task-launcher-local-sink-kafka:jar:1.0.0.BUILD-SNAPSHOT
One way to launch a task using the task-launcher is to use the triggertask source. The triggertask source
will emit a message with a TaskLaunchRequest object containing the required launch information. An example of this
would be to launch the timestamp task once every 5 seconds, the stream to implement this would look like:
stream create foo --definition "triggertask --triggertask.uri=maven://org.springframework.cloud.task.app:timestamp-task:jar:1.0.0.BUILD-SNAPSHOT --trigger.fixed-delay=5 | task-launcher-local" --deploy