Triggers

When a pipeline reaches READY status, Interlock executes its configured trigger to start the downstream job. The trigger.Runner dispatches to type-specific handlers and returns metadata for status polling.

TriggerConfig

trigger:
  type: http           # required: trigger type
  method: POST         # type-specific fields below
  url: https://...
  timeout: 60

Common Fields

Field	Type	Default	Description
`type`	string	—	Trigger type (required)
`timeout`	int	30	Execution timeout in seconds

Trigger Types

`http`

Sends an HTTP request to an arbitrary endpoint.

trigger:
  type: http
  method: POST
  url: https://api.example.com/jobs/start
  headers:
    Authorization: "Bearer ${TOKEN}"
    Content-Type: application/json
  body: '{"pipeline": "my-pipeline", "date": "${DATE}"}'
  timeout: 30

Field	Type	Description
`method`	string	HTTP method (`GET`, `POST`, `PUT`)
`url`	string	Target URL
`headers`	map	HTTP headers
`body`	string	Request body (supports template variables)

`command`

Executes a shell command on the local machine. Only available in local (watcher) mode.

trigger:
  type: command
  command: /usr/local/bin/run-etl --pipeline my-pipeline
  timeout: 300

Field	Type	Description
`command`	string	Shell command to execute

`airflow`

Triggers an Apache Airflow DAG run and polls for completion.

trigger:
  type: airflow
  url: https://airflow.example.com
  dagID: my_dag
  headers:
    Authorization: "Bearer ${AIRFLOW_TOKEN}"
  pollInterval: 1m

Field	Type	Description
`url`	string	Airflow webserver URL
`dagID`	string	DAG identifier
`headers`	map	Authentication headers
`pollInterval`	string	Status poll interval (e.g. `1m`)

`glue`

Starts an AWS Glue job run.

trigger:
  type: glue
  jobName: my-glue-etl
  arguments:
    "--pipeline": my-pipeline
    "--date": "${DATE}"

Field	Type	Description
`jobName`	string	Glue job name
`arguments`	map	Job arguments (keys prefixed with `--`)

Returned metadata: jobRunId — used by run-checker to poll GetJobRun.

`emr`

Submits a step to an existing EMR cluster.

trigger:
  type: emr
  clusterID: j-1234567890ABC
  arguments:
    "--class": com.example.ETLJob
    "--jar": s3://bucket/etl.jar

Field	Type	Description
`clusterID`	string	EMR cluster ID
`arguments`	map	Step arguments

Returned metadata: clusterID, stepId — used by run-checker to poll DescribeStep.

`emr-serverless`

Starts a job run on EMR Serverless.

trigger:
  type: emr-serverless
  applicationID: "00f00abcde12345"
  arguments:
    "--class": com.example.ETLJob
    "--s3-input": s3://bucket/input/

Field	Type	Description
`applicationID`	string	EMR Serverless application ID
`arguments`	map	Job run arguments

Returned metadata: applicationId, jobRunId — used by run-checker to poll GetJobRun.

`step-function`

Starts an AWS Step Functions execution.

trigger:
  type: step-function
  stateMachineARN: arn:aws:states:us-east-1:123456789:stateMachine:my-workflow
  body: '{"input": "value"}'

Field	Type	Description
`stateMachineARN`	string	Step Function state machine ARN
`body`	string	JSON input to the execution

Returned metadata: executionArn — used by run-checker to poll DescribeExecution.

`databricks`

Submits a job run to Databricks via REST API 2.1.

trigger:
  type: databricks
  workspaceURL: https://my-workspace.cloud.databricks.com
  headers:
    Authorization: "Bearer ${DATABRICKS_TOKEN}"
  body: '{"job_id": 12345, "notebook_params": {"date": "${DATE}"}}'

Field	Type	Description
`workspaceURL`	string	Databricks workspace URL
`headers`	map	Authentication headers
`body`	string	JSON request body (Jobs API 2.1 format)

Returned metadata: runId — used by run-checker to poll via GET /api/2.1/jobs/runs/get.

Template Variables

The body and arguments fields support template substitution. Variables are resolved at trigger time:

Variable	Value
`${DATE}`	Current date (`YYYY-MM-DD`)
`${PIPELINE}`	Pipeline ID
`${SCHEDULE}`	Schedule ID
`${RUN_ID}`	Run ID (UUID v4)

Status Polling

After a trigger executes, the run-checker Lambda (or watcher loop) polls for completion using the returned metadata. Each trigger type implements CheckStatus():

Type	SDK Call	Status Mapping
`glue`	`GetJobRun`	RUNNING→running, SUCCEEDED→succeeded, FAILED/STOPPED→failed
`emr`	`DescribeStep`	RUNNING/PENDING→running, COMPLETED→succeeded, FAILED/CANCELLED→failed
`emr-serverless`	`GetJobRun`	RUNNING/SUBMITTED→running, SUCCESS→succeeded, FAILED/CANCELLED→failed
`step-function`	`DescribeExecution`	RUNNING→running, SUCCEEDED→succeeded, FAILED/TIMED_OUT/ABORTED→failed
`databricks`	`GET /runs/get`	RUNNING/PENDING→running, TERMINATED(SUCCESS)→succeeded, others→failed
`airflow`	`GET /dags/{id}/dagRuns`	running→running, success→succeeded, failed→failed

The http and command types are fire-and-forget — they do not support status polling.

Schedules & Exclusions