conductor-python 1.0.13

Netflix Conductor Python SDK

Conductor Python

Software Development Kit for Netflix Conductor, written on and providing support for Python.

Quick Guide

1. Create a virtual environment

   $ virtualenv conductor
   $ source conductor/bin/activate
   $ python3 -m pip list
   Package    Version
   ---------- -------
   pip        22.0.3
   setuptools 60.6.0
   wheel      0.37.1
   

2. Install latest version of conductor-python from pypi

   $ python3 -m pip install conductor-python
   Collecting conductor-python
   Collecting certifi>=14.05.14
   Collecting urllib3>=1.15.1
   Requirement already satisfied: setuptools>=21.0.0 in ./conductor/lib/python3.8/site-packages (from conductor-python) (60.6.0)
   Collecting six>=1.10
   Installing collected packages: certifi, urllib3, six, conductor-python
   Successfully installed certifi-2021.10.8 conductor-python-1.0.7 six-1.16.0 urllib3-1.26.8
   

3. Create a worker capable of executing a Task. Example:

   from conductor.client.http.models.task import Task
   from conductor.client.http.models.task_result import TaskResult
   from conductor.client.http.models.task_result_status import TaskResultStatus
   from conductor.client.worker.worker_interface import WorkerInterface
   
   
   class SimplePythonWorker(WorkerInterface):
       def execute(self, task: Task) -> TaskResult:
           task_result = self.get_task_result_from_task(task)
           task_result.add_output_data('key', 'value')
           task_result.status = TaskResultStatus.COMPLETED
           return task_result
   

   • The add_output_data is the most relevant part, since you can store information in a dictionary, which will be sent within TaskResult as your execution response to Conductor

4. Create a main method to start polling tasks to execute with your worker. Example:

   from conductor.client.automator.task_handler import TaskHandler
   from conductor.client.configuration.configuration import Configuration
   from conductor.client.worker.sample.faulty_execution_worker import FaultyExecutionWorker
   from conductor.client.worker.sample.simple_python_worker import SimplePythonWorker
   
   
   def main():
       configuration = Configuration(debug=True)
       task_definition_name = 'python_task_example'
       workers = [
           FaultyExecutionWorker(task_definition_name),
           SimplePythonWorker(task_definition_name)
       ]
       with TaskHandler(workers, configuration) as task_handler:
           task_handler.start_processes()
           task_handler.join_processes()
   
   
   if __name__ == '__main__':
       main()
   

   • This example contains two workers, each with a different execution method, capable of running the same task_definition_name

5. Now that you have implemented the example, you can start the Conductor server locally:

   1. Clone Netflix Conductor repository:

      $ git clone https://github.com/Netflix/conductor.git
      $ cd conductor/
      

   2. Start the Conductor server:

      /conductor$ ./gradlew bootRun
      

   3. Start Conductor UI:

      /conductor$ cd ui/
      /conductor/ui$ yarn install
      /conductor/ui$ yarn run start
      

   You should be able to access:

   • Conductor API:
     • http://localhost:8080/swagger-ui/index.html
   • Conductor UI:
     • http://localhost:5000

6. Create a Task within Conductor. Example:

   $ curl -X 'POST' \
       'http://localhost:8080/api/metadata/taskdefs' \
       -H 'accept: */*' \
       -H 'Content-Type: application/json' \
       -d '[
       {
         "name": "python_task_example",
         "description": "Python task example",
         "retryCount": 3,
         "retryLogic": "FIXED",
         "retryDelaySeconds": 10,
         "timeoutSeconds": 300,
         "timeoutPolicy": "TIME_OUT_WF",
         "responseTimeoutSeconds": 180,
         "ownerEmail": "[e-mail]"
       }
     ]'
   

7. Create a Workflow within Conductor. Example:

   $ curl -X 'POST' \
       'http://localhost:8080/api/metadata/workflow' \
       -H 'accept: */*' \
       -H 'Content-Type: application/json' \
       -d '{
       "createTime": 1634021619147,
       "updateTime": 1630694890267,
       "name": "workflow_with_python_task_example",
       "description": "Workflow with Python Task example",
       "version": 1,
       "tasks": [
         {
           "name": "python_task_example",
           "taskReferenceName": "python_task_example_ref_1",
           "inputParameters": {},
           "type": "SIMPLE"
         }
       ],
       "inputParameters": [],
       "outputParameters": {
         "workerOutput": "${python_task_example_ref_1.output}"
       },
       "schemaVersion": 2,
       "restartable": true,
       "ownerEmail": "[e-mail]",
       "timeoutPolicy": "ALERT_ONLY",
       "timeoutSeconds": 0
     }'
   

8. Start a new workflow:

   $ curl -X 'POST' \
       'http://localhost:8080/api/workflow/workflow_with_python_task_example' \
       -H 'accept: text/plain' \
       -H 'Content-Type: application/json' \
       -d '{}'
   

   You should receive a Workflow ID at the Response body

   • Workflow ID example: 8ff0bc06-4413-4c94-b27a-b3210412a914

   Now you must be able to see its execution through the UI.

   • Example: http://localhost:5000/execution/8ff0bc06-4413-4c94-b27a-b3210412a914

9. Run your Python file with the main method

Unit Tests

Simple validation

/conductor-python/src$ python3 -m unittest -v
test_execute_task (tst.automator.test_task_runner.TestTaskRunner) ... ok
test_execute_task_with_faulty_execution_worker (tst.automator.test_task_runner.TestTaskRunner) ... ok
test_execute_task_with_invalid_task (tst.automator.test_task_runner.TestTaskRunner) ... ok

----------------------------------------------------------------------
Ran 3 tests in 0.001s

OK

Run with code coverage

/conductor-python/src$ python3 -m coverage run --source=conductor/ -m unittest

Report:

/conductor-python/src$ python3 -m coverage report

Visual coverage results:

/conductor-python/src$ python3 -m coverage html