Background
Orchestrating a Data Fusion pipeline from external services is a common use case. For example, Data pipelines might be started based on data availability in GCS bucket by Composer and wait for the pipeline to complete. The guide walks through the APIs needed to trigger the pipeline and wait for completion.
Approach
Triggering of the pipeline should get the run id of the pipeline that is started. Inorder to get the RunId the following endpoint should be used
POST v3/namespaces/<namespaceid>/start
Request Body: ['{“appId”:”<pipelinename>”, “programType”:”workflow”,
“programId”:”DataPipelineWorkflow”, "runtimeargs": { "arg1":"val1" } }']
Sample Call
Request: curl -X POST http://localhost:11015/v3/namespaces/default/start
-d '[{"appId": "Test", "programType": "workflow", "programId":"DataPipelineWorkflow", "runtimeargs": { "path":"gs://mybucket/csv/data.txt" }}]'
Response: [{"statusCode":200,"runId":"e6523380-a73a-11ea-a21e-acde48001122","appId":"Test","programType":"Workflow","programId":"DataPipelineWorkflow"}]
Note: Any non 200 response from the REST API should be handled by the calling program which includes 504 (Timeout errors), 4xx (User errors)
2. Once the pipeline is started the pipeline run can be monitored by using the status endpoint
GET v3/namespaces/<namespaceid>/apps/<pipelinename>/workflows/DataPipelineWorkflow/runs/<runid>
The status of the run will be returned in the status field in the response
Sample call
Request: curl http://localhost:11015/v3/namespaces/default/apps/Test/workflows/DataPipelineWorkflow/runs/e6523380-a73a-11ea-a21e-acde48001122
Response: {"runid":"e6523380-a73a-11ea-a21e-acde48001122","starting":1591368200,"start":1591368209,"end":1591368220,"status":"FAILED","properties":{"runtimeArgs":"{\"logical.start.time\":\"1591368200231\"}","phase-1":"ebdb21e1-a73a-11ea-bb32-acde48001122"},"cluster":{"status":"DEPROVISIONED","end":1591368223,"numNodes":0},"profile":{"profileName":"native","namespace":"system","entity":"PROFILE"}}