Managing workflows in Argo can involve complex scripts and automation processes. A common requirement is ensuring workflows terminate immediately when a script exits, especially in error scenarios or when specific conditions are met. This guide explains how to configure your Argo workflow to stop when a script exits.
Why Stop a Workflow When a Script Exits?
Stopping a workflow upon script exit is crucial for:
1. Error Handling: Prevents cascading failures and unnecessary resource usage.
2. Efficiency: Saves time by halting workflows when conditions are not met.
3. Cost Management: Reduces operational costs in cloud environments by terminating unused resources.
Steps to Stop Workflow on Script Exit
1. Use onExit Hooks:
• Argo workflows support onExit hooks, which allow you to define actions when a script or task exits.
• Example:
onExit: exit-handler
2. Set Exit Codes in Your Script:
• Ensure your script exits with specific codes:
• 0 for success.
• Non-zero for errors.
• Example:
if [ condition ]; then
exit 0
else
exit 1
fi
3. Configure Workflow Steps:
• Add a conditional check in your workflow YAML:
steps:
– name: run-script
template: script-template
continueOn:
failed: false
4. Implement Retry Logic (Optional):
• If applicable, define retry logic to handle transient errors:
retryStrategy:
limit: 3
backoff:
duration: 2s
5. Test the Workflow:
• Execute the workflow and simulate different script exits to ensure proper termination.
apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
generateName: script-exit-example-
spec:
entrypoint: main
templates:
– name: main
steps:
– – name: run-script
template: script-template
– name: script-template
script:
image: python:3.9
command: [“python”]
source: |
import sys
if condition_met:
sys.exit(0)
else:
sys.exit(1)
Common Challenges and Solutions
1. Scripts Not Exiting Properly:
• Ensure the script uses explicit exit codes.
2. Workflow Hangs:
• Use timeouts or termination policies to handle stalled workflows.
3. Debugging Errors:
• Check Argo logs for detailed information about workflow termination.
Conclusion
Stopping workflows when a script exits is an essential feature for efficient workflow management in Argo. By leveraging onExit hooks, proper exit codes, and robust YAML configurations, you can create reliable and cost-effective workflows tailored to your needs.
