8. Functions

Register the out-of-the-box applications for the Rabbit binder

Note

These samples assume that the Data Flow Server can access a remote Maven repository, repo.spring.io/libs-release by default. If your Data Flow server is running behind a firewall, or you are using a maven proxy preventing access to public repositories, you will need to install the sample apps in your internal Maven repository and configure the server accordingly. The sample applications are typically registered using Data Flow’s bulk import facility. For example, the Shell command dataflow:>app import --uri dataflow.spring.io/rabbitmq-maven-latest (The actual URI is release and binder specific so refer to the sample instructions for the actual URL). The bulk import URI references a plain text file containing entries for all of the publicly available Spring Cloud Stream and Task applications published to repo.spring.io. For example, source.http=maven://org.springframework.cloud.stream.app:http-source-rabbit:2.1.0.RELEASE registers the http source app at the corresponding Maven address, relative to the remote repository(ies) configured for the Data Flow server. The format is maven://<groupId>:<artifactId>:<version> You will need to download the required apps or build them and then install them in your Maven repository, using whatever group, artifact, and version you choose. If you do this, register individual apps using dataflow:>app register…​ using the maven:// resource URI format corresponding to your installed app.

dataflow:>app import --uri https://dataflow.spring.io/rabbitmq-maven-latest

Register the out-of-the-box function-runner application (current release is at 1.0.0.M1)

dataflow:>app register --name function-runner --type processor --uri maven://org.springframework.cloud.stream.app:function-app-rabbit:1.0.0.M1 --metadata-uri maven://org.springframework.cloud.stream.app:function-app-rabbit:jar:metadata:1.0.0.M1

Create and deploy the following stream

dataflow:>stream create foo --definition "http --server.port=9001 | function-runner --function.className=com.example.functions.CharCounter --function.location=file:///<PATH/TO/SPRING-CLOUD-FUNCTION>/spring-cloud-function-samples/function-sample/target/spring-cloud-function-sample-1.0.0.BUILD-SNAPSHOT.jar | log" --deploy

	Note
	Replace the <PATH/TO/SPRING-CLOUD-FUNCTION> with the correct path.

	Note
	The source core of CharCounter function is in Spring cloud Function’s samples repo.

Verify the stream is successfully deployed.

dataflow:>stream list

Notice that foo-http, foo-function-runner, and foo-log Spring Cloud Stream applications are running as Spring Boot applications and the log locations will be printed in the Local-server console.

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2017-10-17 11:43:03.714  INFO 18409 --- [nio-9393-exec-7] o.s.c.d.s.s.AppDeployerStreamDeployer    : Deploying application named [log] as part of stream named [foo] with resource URI [maven://org.springframework.cloud.stream.app:log-sink-rabbit:jar:1.2.0.RELEASE]
2017-10-17 11:43:04.379  INFO 18409 --- [nio-9393-exec-7] o.s.c.d.spi.local.LocalAppDeployer       : Deploying app with deploymentId foo.log instance 0.
   Logs will be in /var/folders/c3/ctx7_rns6x30tq7rb76wzqwr0000gs/T/spring-cloud-dataflow-6549025456609489200/foo-1508265783715/foo.log
2017-10-17 11:43:04.380  INFO 18409 --- [nio-9393-exec-7] o.s.c.d.s.s.AppDeployerStreamDeployer    : Deploying application named [function-runner] as part of stream named [foo] with resource URI [file:/var/folders/c3/ctx7_rns6x30tq7rb76wzqwr0000gs/T/deployer-resource-cache8941581850579153886/http-c73a62adae0abd7ec0dee91d891575709f02f8c9]
2017-10-17 11:43:04.384  INFO 18409 --- [nio-9393-exec-7] o.s.c.d.spi.local.LocalAppDeployer       : Deploying app with deploymentId foo.function-runner instance 0.
   Logs will be in /var/folders/c3/ctx7_rns6x30tq7rb76wzqwr0000gs/T/spring-cloud-dataflow-6549025456609489200/foo-1508265784380/foo.function-runner
2017-10-17 11:43:04.385  INFO 18409 --- [nio-9393-exec-7] o.s.c.d.s.s.AppDeployerStreamDeployer    : Deploying application named [http] as part of stream named [foo] with resource URI [maven://org.springframework.cloud.stream.app:http-source-rabbit:jar:1.2.0.RELEASE]
2017-10-17 11:43:04.391  INFO 18409 --- [nio-9393-exec-7] o.s.c.d.spi.local.LocalAppDeployer       : Deploying app with deploymentId foo.http instance 0.
   Logs will be in /var/folders/c3/ctx7_rns6x30tq7rb76wzqwr0000gs/T/spring-cloud-dataflow-6549025456609489200/foo-1508265784385/foo.http
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Post sample data to the http endpoint: localhost:9001 (9001 is the port we specified for the http source in this case)

dataflow:>http post --target http://localhost:9001 --data "hello world"
> POST (text/plain) http://localhost:9001 hello world
> 202 ACCEPTED


dataflow:>http post --target http://localhost:9001 --data "hmm, yeah, it works now!"
> POST (text/plain) http://localhost:9001 hmm, yeah, it works now!
> 202 ACCEPTED

Tail the log-sink’s standard-out logs to see the character counts

$ tail -f /var/folders/c3/ctx7_rns6x30tq7rb76wzqwr0000gs/T/spring-cloud-dataflow-6549025456609489200/foo-1508265783715/foo.log/stdout_0.log

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2017-10-17 11:45:39.363  INFO 19193 --- [on-runner.foo-1] log-sink       : 11
2017-10-17 11:46:40.997  INFO 19193 --- [on-runner.foo-1] log-sink       : 24
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