tenant-identifier-shared

Multi-Tenancy with Tenant Identifiers for Shared Process Engine

This example demonstrates how to use multi-tenancy for a shared process engine. You learn

• How to deploy a process definition with a tenant-id,
• How to start a process instance from a process definition with a tenant-id,
• How to implement a service task which uses the tenant-id from the process instance,
• How to use multi-tenancy with Camunda Web Applications

The example process for the tenants looks like:

How it works

Please refer to the User Guide for details about multi-tenancy.

Deploy a Process Definition with Tenant-Id

Create a processes.xml deployment descriptor which includes one process-archive per tenant.

<process-application
  xmlns="http://www.camunda.org/schema/1.0/ProcessApplication"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

  <process-archive name="tenant1-archive" tenantId="tenant1">
    <process-engine>default</process-engine>
    <properties>
      <property name="resourceRootPath">classpath:processes/tenant1/</property>

      <property name="isDeleteUponUndeploy">false</property>
      <property name="isScanForProcessDefinitions">true</property>
    </properties>
  </process-archive>

  <process-archive name="tenant2-archive" tenantId="tenant2">
    <process-engine>default</process-engine>
    <properties>
      <property name="resourceRootPath">classpath:processes/tenant2/</property>

      <property name="isDeleteUponUndeploy">false</property>
      <property name="isScanForProcessDefinitions">true</property>
    </properties>
  </process-archive>

</process-application>

Start a Process Instance from a Tenant Specific Process Definition

Implement a ServletProcessApplication to start process instances when the application starts.

@ProcessApplication(name="Multi-Tenancy App")
public class MultiTenancyProcessApplication extends ServletProcessApplication {

  @PostDeploy
  public void startProcessInstances(ProcessEngine processEngine) {

    RepositoryService repositoryService = processEngine.getRepositoryService();
    RuntimeService runtimeService = processEngine.getRuntimeService();

    // start a process instance for 'tenant1'
    runtimeService
      .createProcessInstanceByKey("example-process")
      .processDefinitionTenantId("tenant1")
      .execute();

    // next, start a process instance for 'tenant2'
    runtimeService
      .createProcessInstanceByKey("example-process")
      .processDefinitionTenantId("tenant2")
      .execute();
  }
}

Implement a Tenant-Aware Service Task

Implement a service task as JavaDelegate that can be used for multiple tenants. While execution, it retrieves the tenant-id from the execution (i.e. the process instance) and do some tenant specific logic.

public class TenantAwareServiceTask implements JavaDelegate {

  @Override
  public void execute(DelegateExecution execution) throws Exception {

    String tenantId = execution.getTenantId();

    // do some logic based on the tenant-id (e.g. invoke a tenant-aware service)
  }
}

How to use it?

1. Checkout the project with Git
2. Import the project into your IDE
3. Build it with Maven
4. Deploy it to a shared process engine distribution of your own choice (Tomcat, Wildfly, Weblogic, Websphere - this example does not work with Camunda Platform Run)
5. Check the console or the log file if you can find: TenantAwareServiceTask.execute invoked for tenant with id: tenant1 and TenantAwareServiceTask.execute invoked for tenant with id: tenant2

Check the Result in Camunda Web Applications

1. Open your browser and go to http://localhost:8080/camunda/app/cockpit
2. Log in with demo / demo as member of group camunda-admin
3. Check that you see two deployed process definitions with key example-process - one for each tenant
4. Switch to Admin and create a new user
5. Go to tenant section and create a new tenant with id tenant1
6. Select the user and assign the tenant tenant1 to it
7. Make sure that the user has the permissions to read process definitions and access Cockpit Web Application
8. Switch to Cockpit and log in with the new user
9. Check that the user see only one deployed process definition with key example-process