Email Notifications

Dagu provides built-in email notifications for workflow events and errors.

SMTP Configuration

Global Configuration

Set up SMTP settings in your Dagu configuration:

# ~/.config/dagu/config.yaml
smtp:
  host: smtp.gmail.com
  port: "587"
  username: alerts@example.com
  password: app-specific-password
  
errorMail:
  from: alerts@example.com
  to: team@example.com  # Single recipient (string format)
  prefix: "[Dagu Alert]"
  attachLogs: true

Environment Variables

Configure SMTP via environment:

export DAGU_SMTP_HOST=smtp.gmail.com
export DAGU_SMTP_PORT=587
export DAGU_SMTP_USERNAME=alerts@example.com
export DAGU_SMTP_PASSWORD=secret-password

export DAGU_ERROR_MAIL_FROM=alerts@example.com
export DAGU_ERROR_MAIL_TO=team@example.com
export DAGU_ERROR_MAIL_PREFIX="[Alert]"

DAG-Level Configuration

Override global settings per DAG:

# my-dag.yaml
smtp:
  host: smtp.company.com
  port: "465"
  username: ${SMTP_USER}
  password: ${SMTP_PASS}

errorMail:
  from: dagu@company.com
  to: 
    - oncall@company.com
    - manager@company.com
  prefix: "[CRITICAL]"
  attachLogs: true

mailOn:
  success: true
  failure: true
  wait: true

waitMail:
  from: dagu@company.com
  to:
    - approvers@company.com
  prefix: "[WAITING]"
  attachLogs: false

Email Triggers

Success/Failure/Wait Emails

mailOn:
  success: true    # Email on successful completion
  failure: true    # Email on failure
  wait: true       # Email when waiting for human approval

Step-Level Errors

steps:
  - name: critical-step
    command: process_critical_data.sh
    mailOnError: true  # Email if this step fails

Wait Status Notifications

Send notifications when a DAG is waiting for human approval (HITL - Human In The Loop):

mailOn:
  wait: true

waitMail:
  from: dagu@company.com
  to:
    - approvers@company.com
  prefix: "[APPROVAL REQUIRED]"
  attachLogs: false

This is useful for workflows that require human approval before continuing execution. The email will include details about the DAG and which steps are waiting.

Mail Step Type

Send custom emails as workflow steps:

steps:
  - name: send report
    type: mail
    config:
      to:
        - command: reports@example.com
        - command: archive@example.com
      from: noreply@example.com
      subject: "Daily Report - ${TODAY}"
      message: |
        Daily processing report for ${TODAY}

        Summary:
        - command: Records processed: ${RECORD_COUNT}
        - command: Success rate: ${SUCCESS_RATE}%
        - command: Processing time: ${DURATION}

        See attached files for details.
      attachments:
        - command: /reports/daily-${TODAY}.pdf
        - command: /reports/summary-${TODAY}.csv
        - command: ${DAG_RUN_LOG_FILE}

Email Templates

Processing Report

steps:
  - name: generate report
    command: generate_report.py
    output: REPORT_PATH
  
  - name: email report
    type: mail
    config:
      to: stakeholders@example.com
      subject: "Processing Report - ${DAG_NAME}"
      message: |
        Automated Report Generated

        DAG: ${DAG_NAME}
        Run ID: ${DAG_RUN_ID}
        Status: Completed
        Time: $(date)

        Report available at: ${REPORT_PATH}
      attachments:
        - command: ${REPORT_PATH}

Error Notification

handlerOn:
  failure:
    type: mail
    config:
      to:
        - oncall@example.com
        - alerts@example.com
      from: errors@example.com
      subject: "⚠️ DAG Failed: ${DAG_NAME}"
      message: |
        DAG Execution Failed

        Details:
        - DAG: ${DAG_NAME}
        - Run ID: ${DAG_RUN_ID}
        - Time: $(date)
        - Host: $(hostname)

        Error Summary:
        $(tail -20 ${DAG_RUN_LOG_FILE} | grep -i error)

        Full log attached.
      attachments:
        - ${DAG_RUN_LOG_FILE}

SMTP Providers

Gmail

smtp:
  host: smtp.gmail.com
  port: "587"
  username: your-email@gmail.com
  password: app-specific-password  # Use app password, not regular password

Office 365

smtp:
  host: smtp.office365.com
  port: "587"
  username: your-email@company.com
  password: your-password

SendGrid

smtp:
  host: smtp.sendgrid.net
  port: "587"
  username: apikey
  password: ${SENDGRID_API_KEY}

AWS SES

smtp:
  host: email-smtp.us-east-1.amazonaws.com
  port: "587"
  username: ${AWS_SES_SMTP_USERNAME}
  password: ${AWS_SES_SMTP_PASSWORD}

Advanced Configuration

Multiple Recipients

errorMail:
  to:
    - primary@example.com
    - secondary@example.com
    - team-alerts@example.com

Conditional Recipients

steps:
  - name: check environment
    command: echo $ENVIRONMENT
    output: ENV
  
  - name: notify
    type: mail
    config:
      to: |
        `if [ "${ENV}" = "production" ]; then
          echo "prod-alerts@example.com"
        else
          echo "dev-alerts@example.com"
        fi`
      subject: "Alert from ${ENV}"
      message: "Environment-specific alert"

HTML Emails

steps:
  - name: send html email
    type: mail
    config:
      to: reports@example.com
      subject: "HTML Report"
      message: |
        <html>
        <body>
          <h1>Daily Report</h1>
          <table border="1">
            <tr>
              <td>Status</td>
              <td style="color: green;">Success</td>
            </tr>
            <tr>
              <td>Records</td>
              <td>${RECORD_COUNT}</td>
            </tr>
          </table>
        </body>
        </html>
      headers:
        Content-Type: text/html