knative-statemachine-runner

README

KNative StateMachine Runner

This project runs a StateMachine definition and keeps track of its state.

For more information look at the Knative StateMachine Controller project which creates new StateMachine Runners.

APIs

Each Runner instance expose the following REST endpoints:

• POST /statemachines/ Creates a new StateMachineInstance, returns a unique id
• POST /statemachines/events Consume Cloud Events for a given StateMachineInstance
• GET /statemachines/ Get all available StateMachineInstances
• GET /statemachines/{id} Get StateMachineInstance by id

Running the project from Source

go build

go run main.go

Publish to local registry, it uses KO_DOCKER_REGISTRY var to decide where to publish

ko publish .

Example

This example create a new State Machine instance by sending a POST request to the following endpoint

curl -X POST http://localhost:8080/statemachines

Once you have the Id of the State Machine Instance, then you can send events to that specific instance.

curl -X POST -H "Content-Type: application/json" \
  -H "ce-specversion: 1.0" \
  -H "ce-source: curl-command" \
  -H "ce-type: JoinedQueue" \
  -H "ce-id: 123-abc" \
  -H "ce-statemachineid: 7e3e2258-fe78-11eb-a85e-acde48001122" \
  -d '{"name":"Salaboy"}' \
  http://localhost:8080/statemachines/events

Another option that might work better if you don't want to add an extra request to track the state of an existing flow is to use a Correlation Key.

In this case you don't need to create the instance, but you need to specify a correlation key that will be used for all the future events against that instance.

curl -X POST -H "Content-Type: application/json" \
  -H "ce-specversion: 1.0" \
  -H "ce-source: curl-command" \
  -H "ce-type: JoinedQueue" \
  -H "ce-id: 123-abc" \
  -H "ce-correlationkey: tickets-123" \
  -d '{"name":"Salaboy"}' \
  http://localhost:8080/statemachines/events

Now, tickets-123 will be used as a correlation key to correlate future events.