517ccd5b40
Migrating the existing structure from the following location: https://github.com/spring-cloud-stream-app-starters/stream-applications/tree/restructuring
53 lines
2.5 KiB
Plaintext
53 lines
2.5 KiB
Plaintext
=== `Data Flow Task Launch Request Support` Common Module
|
|
|
|
This artifact contains a Spring Boot auto-configuration providing components to produce a Task Launch Request payload.
|
|
In theory any message source can be used to launch a Task. The task launch request is compatible with the
|
|
task-launcher-dataflow sink.
|
|
|
|
|
|
==== Data Flow Task Launch Request
|
|
|
|
Data Flow Task Launch Request requests require a Data Flow server with an existing task definition.
|
|
The task launch request contains the name of the task to launch. This must the name of a defined task in Data Flow.
|
|
You may optionally provide command line arguments and deployment properties.
|
|
|
|
===== Task Name
|
|
|
|
The task name is a required field. This may be statically configured by setting `task.launch.request.task-name`,
|
|
extracted from the Message by setting `task.launch.request.task-name-expression`.
|
|
You may also override the default implementation of the `TaskNameMessageMapper` bean to enable more complex runtime task name mappings.
|
|
|
|
|
|
===== Task Command Line Arguments
|
|
|
|
The launched task often requires additional data which may be passed as command line arguments.
|
|
The `task.launch.request.args` property accepts a comma delimited string of key-value pairs, for example
|
|
`key1=val1,key2=val2`. In addition, a `task.launch.request.arg-expressions` allows you to use SpEL expressions to evaluate
|
|
message contents to provide command line arguments.
|
|
For example, `task.launch.request.arg-expressions=foo=payload.toUpperCase(),bar=payload.substring(0,2)`.
|
|
|
|
You may also provide override implementation of the `CommandLineArgumentsMessageMapper` bean to implement more complex logic.
|
|
|
|
===== Task Deployment Properties
|
|
|
|
Deployment properties are platform-specific configuration used by the `TaskLauncher` and are always statically configured by
|
|
setting `task.launch.request.deployment-properties` and apply to every task launch request.
|
|
|
|
=== Configuration
|
|
To enable any stream app to transform its output to a Task Launch Request, include a dependency on this module
|
|
|
|
[source,xml]
|
|
----
|
|
<dependency>
|
|
<groupId>org.springframework.cloud.stream.app</groupId>
|
|
<artifactId>app-starters-task-launch-request-common</artifactId>
|
|
</dependency>
|
|
----
|
|
|
|
Setting the application property `spring.cloud.stream.function.definition=taskLaunchRequest` is required to execute the transformation.
|
|
You may safely add the above dependency to applications which optionally produce a task launch request.
|
|
|
|
|
|
`TaskLaunchRequestIntegrationTests` provides some configuration examples.
|
|
|