Examples

Quick reference for all Dagu features. Each example is minimal and copy-paste ready.

Basic Workflow Patterns

Basic Sequential Steps

yaml

steps:
  - name: first
    command: echo "Step 1"
  - name: second
    command: echo "Step 2"

Execute steps one after another.

Learn more →

Parallel Execution

yaml

steps:
  - name: process-items
    run: processor
    parallel:
      items: [A, B, C]
      maxConcurrent: 2

Process multiple items simultaneously.

Learn more →

Complex Dependencies

yaml

steps:
  - name: setup
    command: ./setup.sh
  - name: test-a
    command: ./test-a.sh
    depends: setup
  - name: test-b
    command: ./test-b.sh
    depends: setup
  - name: deploy
    command: ./deploy.sh
    depends:
      - test-a
      - test-b

Define complex dependency graphs.

Learn more →

Chain vs Graph Execution

yaml

# Chain type (default) - automatic dependencies
type: chain
steps:
  - name: download
    command: wget data.csv
  - name: process
    command: python process.py  # Depends on download
  - name: upload
    command: aws s3 cp output.csv s3://bucket/

---

# Graph type - explicit dependencies
type: graph  
steps:
  - name: step1
    command: echo "First"
  - name: step2
    command: echo "Second"
    depends: step1  # Explicit dependency required

Control execution flow patterns.

Learn more →

Control Flow & Conditions

Conditional Execution

yaml

steps:
  - name: deploy
    command: ./deploy.sh
    preconditions:
      - condition: "${ENV}"
        expected: "production"

Run steps only when conditions are met.

Learn more →

Advanced Preconditions

yaml

steps:
  - name: conditional-task
    command: ./process.sh
    preconditions:
      - test -f /data/input.csv
      - test -s /data/input.csv  # File exists and is not empty
      - condition: "${ENVIRONMENT}"
        expected: "production"
      - condition: "`date '+%d'`"
        expected: "re:0[1-9]"  # First 9 days of month
      - condition: "`df -h /data | awk 'NR==2 {print $5}' | sed 's/%//'`"
        expected: "re:^[0-7][0-9]$"  # Less than 80% disk usage

Multiple condition types and regex patterns.

Learn more →

Repeat Until Condition

yaml

steps:
  - name: wait-for-service
    command: curl -f http://service/health
    repeatPolicy:
      intervalSec: 10
      exitCode: [1]  # Repeat while exit code is 1

Repeat steps until success.

Learn more →

Repeat Until Success

yaml

steps:
  - name: wait-for-service
    command: curl -f http://service:8080/health
    repeatPolicy:
      intervalSec: 10
      exitCode: [1]  # Repeat while curl fails
  
  - name: monitor-job
    command: ./check_job_status.sh
    output: JOB_STATUS
    repeatPolicy:
      condition: "${JOB_STATUS}"
      expected: "COMPLETED"
      intervalSec: 30

Wait for external dependencies and job completion.

Learn more →

Repeat Steps

yaml

steps:
  - name: repeating task
    command: main.sh
    repeatPolicy:
      repeat: true
      intervalSec: 60

Execute steps periodically.

Learn more →

Error Handling & Reliability

Continue on Failure

yaml

steps:
  - name: optional-task
    command: ./nice-to-have.sh
    continueOn:
      failure: true
  - name: required-task
    command: ./must-succeed.sh

Handle non-critical failures gracefully.

Learn more →

Retry on Failure

yaml

steps:
  - name: api-call
    command: curl https://api.example.com
    retryPolicy:
      limit: 3
      intervalSec: 30

Automatically retry failed steps.

Learn more →

Smart Retry Policies

yaml

steps:
  - name: api-with-smart-retry
    command: ./api_call.sh
    retryPolicy:
      limit: 5
      intervalSec: 30
      exitCodes: [429, 503, 504]  # Rate limit, service unavailable

Targeted retry policies for different error types.

Learn more →

Lifecycle Handlers

yaml

handlerOn:
  success:
    command: ./notify-success.sh
  failure:
    command: ./cleanup-on-fail.sh
  exit:
    command: ./always-cleanup.sh
steps:
  - name: main
    command: ./process.sh

Run handlers on workflow events.

Learn more →

Data & Variables

Environment Variables

yaml

env:
  - SOME_DIR: ${HOME}/batch
  - SOME_FILE: ${SOME_DIR}/some_file
  - LOG_LEVEL: debug
  - API_KEY: ${SECRET_API_KEY}
steps:
  - name: task
    dir: ${SOME_DIR}
    command: python main.py ${SOME_FILE}

Define variables accessible throughout the DAG.

Learn more →

Dotenv Files

yaml

# Specify single dotenv file
dotenv: .env

# Or specify multiple candidate files
dotenv:
  - .env
  - .env.local
  - configs/.env.prod

steps:
  - name: use-env-vars
    command: echo "Database: ${DATABASE_URL}"

Load environment variables from .env files.

Learn more →

Positional Parameters

yaml

params: param1 param2  # Default values for $1 and $2
steps:
  - name: parameterized task
    command: python main.py $1 $2

Define default positional parameters.

Learn more →

Named Parameters

yaml

params:
  - FOO: 1           # Default value for ${FOO}
  - BAR: "`echo 2`"  # Command substitution in defaults
  - ENVIRONMENT: dev
steps:
  - name: named params task
    command: python main.py ${FOO} ${BAR} --env=${ENVIRONMENT}

Define named parameters with defaults.

Learn more →

Output Variables

yaml

steps:
  - name: get-version
    command: cat VERSION
    output: VERSION
  - name: use-version
    command: echo "Version is ${VERSION}"
    depends: get-version

Pass data between steps.

Learn more →

Output Size Limits

yaml

# Set maximum output size to 5MB for all steps
maxOutputSize: 5242880  # 5MB in bytes

steps:
  - name: large-output
    command: "cat large-file.txt"
    output: CONTENT  # Will fail if file exceeds 5MB

Control output size limits to prevent memory issues.

Learn more →

Redirect Output to Files

yaml

steps:
  - name: redirect stdout
    command: "echo hello"
    stdout: "/tmp/hello"
  
  - name: redirect stderr
    command: "echo error message >&2"
    stderr: "/tmp/error.txt"

Send output to files instead of capturing.

Learn more →

JSON Path References

yaml

steps:
  - name: child DAG
    run: sub_workflow
    output: SUB_RESULT
  - name: use nested output
    command: echo "Result: ${SUB_RESULT.outputs.finalValue}"
    depends: child DAG

Access nested JSON data with path references.

Learn more →

Step ID References

yaml

steps:
  - name: extract customer data
    id: extract
    command: python extract.py
    output: DATA
  - name: process if valid
    command: |
      echo "Exit code: ${extract.exit_code}"
      echo "Stdout path: ${extract.stdout}"
    depends: extract

Reference step properties using short IDs.

Learn more →

Command Substitution

yaml

env:
  TODAY: "`date '+%Y%m%d'`"
steps:
  - name: use date
    command: "echo hello, today is ${TODAY}"

Use command output in configurations.

Learn more →

Scripts & Code

Shell Scripts

yaml

steps:
  - name: script step
    script: |
      cd /tmp
      echo "hello world" > hello
      cat hello
      ls -la

Run shell script with default shell.

Learn more →

Python Scripts

yaml

steps:
  - name: python script
    command: python
    script: |
      import os
      import datetime
      
      print(f"Current directory: {os.getcwd()}")
      print(f"Current time: {datetime.datetime.now()}")

Execute script with specific interpreter.

Learn more →

Multi-Step Scripts

yaml

steps:
  - name: complex-task
    script: |
      #!/bin/bash
      set -e
      
      echo "Starting process..."
      ./prepare.sh
      
      echo "Running main task..."
      ./main-process.sh
      
      echo "Cleaning up..."
      ./cleanup.sh

Run multi-line scripts.

Learn more →

Working Directory

yaml

steps:
  - name: step in specific directory
    dir: /path/to/working/directory
    command: pwd && ls -la

Control where each step executes.

Learn more →

Shell Selection

yaml

steps:
  - name: bash specific
    command: echo hello world | xargs echo
    shell: bash
  
  - name: with pipes
    command: echo hello world | xargs echo

Specify shell or use pipes in commands.

Learn more →

Executors & Integrations

Docker Executor

yaml

steps:
  - name: build
    executor:
      type: docker
      config:
        image: node:18
    command: npm run build

Run commands in Docker containers.

Learn more →

SSH Remote Execution

yaml

steps:
  - name: remote
    executor:
      type: ssh
      config:
        host: server.example.com
        user: deploy
    command: ./deploy.sh

Execute commands on remote servers.

Learn more →

HTTP Requests

yaml

steps:
  - name: webhook
    executor:
      type: http
      config:
        url: https://api.example.com/webhook
        method: POST
        headers:
          Content-Type: application/json
        body: '{"status": "started"}'

Make HTTP API calls.

Learn more →

JSON Processing

yaml

steps:
  - name: get-data
    command: curl -s https://api.example.com/users
    output: API_RESPONSE
  
  - name: extract-emails
    executor:
      type: jq
      config:
        query: '.data[] | select(.active == true) | .email'
    command: echo "${API_RESPONSE}"
    output: USER_EMAILS

API integration with JSON processing pipeline.

Learn more →

Scheduling & Automation

Basic Scheduling

yaml

schedule: "5 4 * * *"  # Run at 04:05 daily
steps:
  - name: scheduled job
    command: job.sh

Use cron expressions to schedule DAGs.

Learn more →

Skip Redundant Runs

yaml

name: Daily Data Processing
schedule: "0 */4 * * *"    # Every 4 hours
skipIfSuccessful: true     # Skip if already succeeded
steps:
  - name: extract
    command: extract_data.sh
  - name: transform
    command: transform_data.sh
  - name: load
    command: load_data.sh

Prevent unnecessary executions when already successful.

Learn more →

Queue Management

yaml

name: batch-job
queue: "batch"        # Assign to named queue
maxActiveRuns: 2      # Max concurrent runs
steps:
  - name: process
    command: process_data.sh

Control concurrent DAG execution.

Learn more →

Global Queue Configuration

yaml

# Global queue config in ~/.config/dagu/config.yaml
queues:
  enabled: true
  config:
    - name: "critical"
      maxConcurrency: 5
    - name: "batch"
      maxConcurrency: 1

# DAG file
queue: "critical"
maxActiveRuns: 3
steps:
  - name: critical-task
    command: ./process.sh

Configure queues globally and per-DAG.

Learn more →

Email Notifications

yaml

mailOn:
  failure: true
  success: true
smtp:
  host: smtp.gmail.com
  port: "587"
  username: "${SMTP_USER}"
  password: "${SMTP_PASS}"
steps:
  - name: critical-job
    command: ./important.sh
    mailOnError: true

Send email alerts on events.

Learn more →

Advanced Patterns

Nested Workflows

yaml

steps:
  - name: data-pipeline
    run: etl.yaml
    params: "ENV=prod DATE=today"
  - name: analyze
    run: analyze.yaml
    depends: data-pipeline

Compose workflows from reusable parts.

Learn more →

Multiple DAGs in One File

yaml

name: main-workflow
steps:
  - name: process-data
    run: data-processor
    params: "TYPE=daily"

---

name: data-processor
params:
  - TYPE: "batch"
steps:
  - name: extract
    command: ./extract.sh ${TYPE}
  - name: transform
    command: ./transform.sh

Define multiple workflows in a single file.

Learn more →

Complete DAG Configuration

yaml

name: production-etl
description: Daily ETL pipeline for analytics
schedule: "0 2 * * *"
skipIfSuccessful: true
group: DataPipelines
tags: daily,critical
queue: etl-queue
maxActiveRuns: 1
maxOutputSize: 5242880  # 5MB
env:
  - LOG_LEVEL: info
  - DATA_DIR: /data/analytics
params:
  - DATE: "`date '+%Y-%m-%d'`"
  - ENVIRONMENT: production
mailOn:
  failure: true
smtp:
  host: smtp.company.com
  port: "587"
handlerOn:
  success:
    command: echo "ETL completed successfully"
  failure:
    command: ./cleanup_on_failure.sh
  exit:
    command: ./final_cleanup.sh
steps:
  - name: validate-environment
    command: ./validate_env.sh ${ENVIRONMENT}

Complete DAG with all configuration options.

Learn more →

Steps as Map vs Array

yaml

# Steps as array (recommended)
steps:
  - name: step1
    command: echo "hello"
  - name: step2
    command: echo "world"
    depends: step1

---

# Steps as map (alternative)
steps:
  step1:
    command: echo "hello"
  step2:
    command: echo "world"
    depends: step1

Two ways to define steps.

Learn more →

Learn More

Writing Workflows Guide - Complete guide to building workflows
Feature Documentation - Deep dive into all features
Configuration Reference - Complete YAML specification

Examples ​

Basic Workflow Patterns ​

Basic Sequential Steps ​

Parallel Execution ​

Complex Dependencies ​

Chain vs Graph Execution ​

Control Flow & Conditions ​

Conditional Execution ​

Advanced Preconditions ​

Repeat Until Condition ​

Repeat Until Success ​

Repeat Steps ​

Error Handling & Reliability ​

Continue on Failure ​

Retry on Failure ​

Smart Retry Policies ​

Lifecycle Handlers ​

Data & Variables ​

Environment Variables ​

Dotenv Files ​

Positional Parameters ​

Named Parameters ​

Output Variables ​

Output Size Limits ​

Redirect Output to Files ​

JSON Path References ​

Step ID References ​

Command Substitution ​

Scripts & Code ​

Shell Scripts ​

Python Scripts ​

Multi-Step Scripts ​

Working Directory ​

Shell Selection ​

Executors & Integrations ​

Docker Executor ​

SSH Remote Execution ​

HTTP Requests ​

JSON Processing ​

Scheduling & Automation ​

Basic Scheduling ​

Skip Redundant Runs ​

Queue Management ​

Global Queue Configuration ​

Email Notifications ​

Advanced Patterns ​

Nested Workflows ​

Multiple DAGs in One File ​

Complete DAG Configuration ​

Steps as Map vs Array ​

Learn More ​

Examples

Basic Workflow Patterns

Basic Sequential Steps

Parallel Execution

Complex Dependencies

Chain vs Graph Execution

Control Flow & Conditions

Conditional Execution

Advanced Preconditions

Repeat Until Condition

Repeat Until Success

Repeat Steps

Error Handling & Reliability

Continue on Failure

Retry on Failure

Smart Retry Policies

Lifecycle Handlers

Data & Variables

Environment Variables

Dotenv Files

Positional Parameters

Named Parameters

Output Variables

Output Size Limits

Redirect Output to Files

JSON Path References

Step ID References

Command Substitution

Scripts & Code

Shell Scripts

Python Scripts

Multi-Step Scripts

Working Directory

Shell Selection

Executors & Integrations

Docker Executor

SSH Remote Execution

HTTP Requests

JSON Processing

Scheduling & Automation

Basic Scheduling

Skip Redundant Runs

Queue Management

Global Queue Configuration

Email Notifications

Advanced Patterns

Nested Workflows

Multiple DAGs in One File

Complete DAG Configuration

Steps as Map vs Array

Learn More