Resume Testing Example¶

This example demonstrates the workflow resumption functionality, allowing you to: - Test workflow failure and recovery - Resume from failed steps - Start from specific steps - Handle required parameters during resumption

Workflow File¶

# Test Resume Workflow
# This workflow is designed to test the workflow resumption functionality.
# It has three steps that can be used to verify different resume scenarios:
#
# How to test:
# 1. Run without required_param - will fail at first step:
#    yaml-workflow run workflows/test_resume.yaml
#
# 2. Resume the failed workflow:
#    yaml-workflow run workflows/test_resume.yaml --resume required_param=test
#
# 3. Try to resume a completed workflow (should fail):
#    yaml-workflow run workflows/test_resume.yaml --resume
#
# 4. Start from a specific step (fresh run):
#    yaml-workflow run workflows/test_resume.yaml --start-from process_data required_param=test

name: Test Resume
description: A simple workflow to test resumption functionality

steps:
  # Step 1: Validate required parameter
  # This step will fail if required_param is not provided
  - name: check_required_param
    task: shell
    command: |
      if [ -z "{{ required_param|default('') }}" ]; then
        echo "Error: required_param is required" >&2
        exit 1
      fi
      echo "required_param is {{ required_param }}"
      echo "{{ required_param }}" > "output/check_result.txt"
    outputs:
      check_result: "{{ required_param }}"

  # Step 2: Process the data
  # Creates a file with the parameter value
  - name: process_data
    task: shell
    command: |
      echo "Processing data with {{ required_param }}"
      echo "{{ required_param }}" > "output/result.txt"
    outputs:
      process_result: "{{ required_param }}"

  # Step 3: Final verification
  # Reads and displays the processed result
  - name: final_step
    task: shell
    command: |
      echo "Final step - reading result"
      cat "output/result.txt"
    outputs:
      final_result: "$(cat output/result.txt)"

Features Demonstrated¶

Workflow Resumption
Resume from failed steps
Start from specific steps
Handle required parameters
Parameter Validation
Required parameter checking
Error handling for missing parameters
Step Dependencies
Sequential step execution
Output capture between steps
File-based state persistence
Error Handling
Graceful failure on missing parameters
Error message output
Exit code handling

Test Scenarios¶

1. Initial Failure¶

Run without required parameter:

yaml-workflow run workflows/test_resume.yaml

Expected output:

Error: required_param is required
Workflow failed at step 'check_required_param'

2. Resume After Failure¶

Resume with required parameter:

yaml-workflow run workflows/test_resume.yaml --resume required_param=test

Expected output:

required_param is test
Processing data with test
Final step - reading result
test

3. Resume Completed Workflow¶

Try to resume a completed workflow:

yaml-workflow run workflows/test_resume.yaml --resume

Expected output:

Error: Cannot resume workflow - no failed state found

4. Start from Specific Step¶

Start from the process_data step:

yaml-workflow run workflows/test_resume.yaml --start-from process_data required_param=test

Expected output:

Processing data with test
Final step - reading result
test

Tips for Testing¶

Clean State
```
rm -rf output/
```

Check Output Files

cat output/check_result.txt
cat output/result.txt

Monitor Step Execution
Watch for step progression
Check error messages
Verify output files