Add Missing endpoints to `ProcessDefinitionRestService.java`

[fenix-hub]

User Story (Required on creation)

Being in need of interacting with a remote Camunda 7 Instance using Quarkus Framework, full Java Rest Client is required (not Spring integrated). However, though there are a couple of Camunda 7 Rest clients online, they always seem to be automatically generated usign OpenAPI generators and so they most of the time have flows. I noticed that there's an engine-rest that could be used for such case. Even though it seems to be a lack of documentation on how to use it, I decided to give it a look. I noticed that currently the ProcessDefinitionRestService is missing multiple endpoints, most importantly those related to starting a process.

• POST /process-definition/{id}/start
• POST /process-definition/key/{key}/start (starts the latest version of process definition which belongs to no tenant)
• POST /process-definition/key/{key}/tenant-id/{tenant-id}/start (starts the latest version of process definition for tenant)

Functional Requirements (Required before implementation)

Add missing endpoints related to starting a process instance by id, key, and with variables.

Technical Requirements (Required before implementation)

[tasso94]

Hi @fenix-hub,

The engine-rest module is our Java-based and server-side REST API implementation.

Currently, we don't provide a Quarkus Extension for our REST API. While we see value in it, we currently don't have time to work on this topic.

Feel free to raise a pull request if you are interested in providing a code contribution.

Best, Tassilo

Edit: You can find the endpoints you were looking for here: https://github.com/camunda/camunda-bpm-platform/blob/332ae16217cd2af9770dc17b1f6ff12fc1e5565d/engine-rest/engine-rest/src/main/java/org/camunda/bpm/engine/rest/sub/repository/ProcessDefinitionResource.java#L65

[tasso94]

Closed due to inactivity.