serverless-workflow-greeting-quarkus

Kogito Serverless Workflow - Greeting Example

Description

This example contains two simple greeting workflow services. The services are described using both JSON and YAML formats as defined in the CNCF Serverless Workflow specification.

The workflow expects as JSON input containing the name of the person to greet, and the language in which to greet them in (see details in the Submit a request section).

The workflow starts with a SWITCH state, which is like a gateway. The switch state decides which language to greet the person in based on the workflow input "language" parameter. Depending on the language the workflow then injects the language-based greeting via RELAY states. Relay states are just "pass" states which do not execute any functions and only have the ability to inject data into the workflow. The inject states then transition to the OPERATION state which call a "sysout" function passing it input parameter containing the greeting and the name of the person to greet: "$.greeting $.name". The function then prints out the greeting to the console.

Installing and Running

Prerequisites

You will need:

• Java 11+ installed
• Environment variable JAVA_HOME set accordingly
• Maven 3.8.6+ installed

When using native image compilation, you will also need:

• GraalVm 19.3.1+ installed
• Environment variable GRAALVM_HOME set accordingly
• Note that GraalVM native image compilation typically requires other packages (glibc-devel, zlib-devel and gcc) to be installed too. You also need 'native-image' installed in GraalVM (using 'gu install native-image'). Please refer to GraalVM installation documentation for more details.

Compile and Run in Local Dev Mode

mvn clean package quarkus:dev

Compile and Run in JVM mode

mvn clean package 
java -jar target/quarkus-app/quarkus-run.jar

or on windows

mvn clean package
java -jar target\quarkus-app\quarkus-run.jar

Compile and Run using Local Native Image

Note that this requires GRAALVM_HOME to point to a valid GraalVM installation

mvn clean package -Pnative

To run the generated native executable, generated in target/, execute

./target/sw-quarkus-greeting-{version}-runner

Submit a request

The service based on the JSON workflow definition can be access by sending a request to http://localhost:8080/jsongreet' with following content

{
  "name": "John",
  "language": "English"
}

Complete curl command can be found below:

curl -X POST -H 'Content-Type:application/json' -H 'Accept:application/json' -d '{"name": "John", "language": "English"}' http://localhost:8080/jsongreet

Log after curl executed:

{"id":"541a5363-1667-4f6d-a8b4-1299eba81eac","workflowdata":{"name":"John","language":"English","greeting":"Hello from JSON Workflow, "}}

In Quarkus you should see the log message printed:

Hello from JSON Workflow, John

If you would like to greet the person in Spanish, we need to pass the following data on workflow start:

{
  "name": "John",
  "language": "Spanish"
}

Complete curl command can be found below:

curl -X POST -H 'Content-Type:application/json' -H 'Accept:application/json' -d '{"name": "John", "language": "Spanish"}' http://localhost:8080/jsongreet

In Quarkus you should now see the log message printed:

Saludos desde JSON Workflow, John

Similarly, the service based on the YAML workflow definition can be access by sending a request to http://localhost:8080/yamlgreet' using the same content:

{
  "name": "John",
  "language": "English"
}

Complete curl command can be found below:

curl -X POST -H 'Content-Type:application/json' -H 'Accept:application/json' -d '{"name": "John", "language": "English"}' http://localhost:8080/yamlgreet

In Quarkus you should see the log message:

Hello from YAML Workflow, John

You can also change the language parameter value to "Spanish" to get the greeting in Spanish.

Deploying with Kogito Operator

In the operator directory you'll find the custom resources needed to deploy this example on OpenShift with the Kogito Operator.