Special Environment Variables

Dagu injects a small set of read-only environment variables whenever it runs a workflow. These variables carry metadata about the current DAG run (name, run identifier, log locations, status) and are available for interpolation inside commands, arguments, lifecycle handlers, and most other places where you can reference environment variables.

Availability

• Step execution – Every step receives the run-level variables plus a step-specific name and log file paths while it executes.
• Lifecycle handlers – onExit, onSuccess, onFailure, and onCancel handlers inherit the same variables. They additionally receive the final DAG_RUN_STATUS so that post-run automation can branch on success or failure.
• Nested contexts – When a step launches a child DAG through the dagu CLI, the child run gets its own identifiers and log locations; the parent identifiers remain accessible in the parent process for chaining or notifications.

Values are refreshed for each step, so DAG_RUN_STEP_NAME, DAG_RUN_STEP_STDOUT_FILE, and DAG_RUN_STEP_STDERR_FILE always point at whichever step (or handler) is currently running.

Reference

Variable	Provided In	Description	Example
DAG_NAME	All steps & handlers	Name of the DAG definition being executed.	daily-backup
DAG_RUN_ID	All steps & handlers	Unique identifier for the current run. Combines timestamp and a short suffix.	20241012_040000_c1f4b2
DAG_RUN_LOG_FILE	All steps & handlers	Absolute path to the aggregated DAG run log. Useful for attaching to alerts.	/var/log/dagu/daily-backup/20241012_040000.log
DAG_RUN_STEP_NAME	Current step or handler only	Name field of the step that is currently executing.	upload-artifacts
DAG_RUN_STEP_STDOUT_FILE	Current step or handler only	File path backing the step’s captured stdout stream.	/var/log/dagu/daily-backup/upload-artifacts.stdout.log
DAG_RUN_STEP_STDERR_FILE	Current step or handler only	File path backing the step’s captured stderr stream.	/var/log/dagu/daily-backup/upload-artifacts.stderr.log
DAG_RUN_STATUS	Lifecycle handlers only	Canonical completion status (succeeded, partially_succeeded, failed, canceled).	failed