Workflow as a Service

Workflow as a service brings an idea of modeling a service as a workflow. In this scenario a workflow is exposed as a fully featured service with a dedicated (domain specific) API. Workflow as a Service aims to cover more traditional service deployments that usually consists of:

a service API exposed over http/rest
an OpenAPI definition for describing services to simplify their use
taking advantage of various integration mechanism to be able to exchange data with different services/systems
ability to be either short lived or long running

In addition, GraphQL service interface can also be added to enhance capabilities of the service.

Workflow as a Service does not really differ from any other developed service. The main advantage it provides is the ability to use the mentioned well established and known workflow languages such as BPMN and DMN as programming languages. Other features are for the most part very similar to those that could be coded by hand.

Get started

To get started with Workflow as a Service users can take advantage of ready to use maven archetypes to generate the project structure

automatiko-archetype - Generic project type that comes with basic setup
automatiko-orchestration-archetype - Tailored for service orchestration scenarios
automatiko-event-stream-archetype - Tailored project type for event stream use case backed by Apache Kafka
automatiko-iot-archetype - Tailored project type for IoT use case backed by MQTT
automatiko-db-archetype - Tailored project type for database record processing use case
automatiko-batch-archetype - Tailored project type for batch processing use case

Here is a ready to use command to generate project based on automatiko-orchestration-archetype

mvn archetype:generate                                      \
  -DarchetypeGroupId=io.automatiko.archetypes               \
  -DarchetypeArtifactId=automatiko-orchestration-archetype  \
  -DarchetypeVersion=LATEST                                 \
  -DgroupId=com.acme.workflows                              \
  -DartifactId=workfow-service

Configure project

Once the project is bootstrapped, it needs to be configured according to the needs. There are two places where configuration is done

pom.xml - definition of the dependencies and Automatiko addons to be used
application.properties - all configuration parameters are defined there (found in src/main/resources directory)

A complete configuration of Automatiko specific configuration parameters can be found here, Quarkus specific configuration parameters can be found here.

Examples

Following is a list of examples that can be tried out to see Workflow as a Service in action

Table 1. Function flow examples
Name	Description	Link
weather-conditions	Weather conditions is implementing Service Orchestration use case.	link
vacation-requests	Vacation requests is implementing Human Centric use case backed by database.	link
support-incidents	Support incidents is implementing Human Centric use case backed by Apache Cassandra database.	link
document-processor	Document processor is implementing Batch processing use case.	link
event-streams-orders	Order management is implementing Event Stream use case backed by Apache Kafka.	link
event-streams-sensors	Water leak detection is implementing Internet of Things use case backed by MQTT.	link