Camunda set tenant id when starting a shared process definition

Question

Is it possible to set a tenant id when the process definition itself is shared between multiple tenants?

I call this method where I get both id's from the http request which in turn I pass to the embedded process-engine

public void startInstance(String processDefinitionId, String tenantId) {
        this.runtimeService.startProcessInstanceById(processDefinitionId);
    }

But using this method I am not able to pass a tenant id to the process instance. How do I achieve this?

I found this reading: https://docs.camunda.org/manual/7.5/user-guide/process-engine/multi-tenancy/#instantiate-a-shared-definition but it does not really solve my problem since I get the tenant id from an http-header.

Answer 1

Thanks to the comment of Jan I figured out that one could add the tenant id as a variable to the started instance and retrieve it in the TenantProvider.

The code looks like this

runtimeService.createProcessInstanceById(processDefinitionId).setVariable("tenantId", tenantId).execute();

And on your TenantProvider simply get this variable like so

public class TenantProvider implements TenantIdProvider {

    @Override
    public String provideTenantIdForProcessInstance(TenantIdProviderProcessInstanceContext ctx) {
        return (String) ctx.getVariables().get("tenantId");
    }

    @Override
    public String provideTenantIdForCaseInstance(TenantIdProviderCaseInstanceContext ctx) {
        return (String) ctx.getVariables().get("tenantId");
    }

    @Override
    public String provideTenantIdForHistoricDecisionInstance(TenantIdProviderHistoricDecisionInstanceContext ctx) {
        return (String) ctx.getExecution().getVariable("tenantId");
    }
}

To enable the use of a TenantProvider, start your engine like so

ProcessEngine engine = new StandaloneProcessEngineConfiguration()
                .setTenantIdProvider(new TenantProvider())
                ...
                .buildProcessEngine();