Notifier

The notification feature is a Dewy component that automatically communicates deployment status to teams. Various events such as success, failure, and hook execution results can be notified via Slack and email.

Supported Notification Methods

Dewy supports the following notification methods:

• Slack (slack://): Notifications to Slack channels
• Mail (mail://, smtp://): Email notifications via SMTP

Notification Timing

Dewy sends notifications at the following times:

• Startup: Dewy service start
• Download completion: New artifact download
• Deploy success: Application startup/restart success
• Error occurrence: Various error occurrences
• Hook execution: Before/After hook execution results
• Shutdown: Dewy service shutdown

Slack Notifications

Basic configuration

# Basic format
slack://<channel-name>

# Example
dewy server --registry ghr://owner/repo \
  --notifier slack://deployments \
  -- /opt/myapp/current/myapp

Environment variables

# Slack Bot Token (required)
export SLACK_TOKEN=xoxb-xxxxxxxxxxxxxxxxxxxxx

Slack App Configuration

1. Create Slack App
   • Create app at https://api.slack.com/apps
2. Required permissions (Scopes)
   • channels:join: Join channels
   • chat:write: Post messages
3. Get token
   • OAuth & Permissions → Bot User OAuth Token

Configuration with Options

# Notification with title
dewy server --registry ghr://owner/repo \
  --notifier "slack://deployments?title=MyApp"

# Notification with URL (link to repository, etc.)
dewy server --registry ghr://owner/repo \
  --notifier "slack://deployments?title=MyApp&url=https://github.com/owner/repo"

# Multiple options
dewy server --registry ghr://owner/repo \
  --notifier "slack://prod-deploy?title=MyApp&url=https://myapp.example.com"

Example Notification Content

🚀 Automatic shipping started by Dewy (v1.2.3: server)

✅ Downloaded artifact for v1.2.3

🔄 Server restarted for v1.2.3

❌ Deploy failed: connection timeout

Email Notifications

Basic configuration

# Basic format
mail://<smtp-host>:<port>/<recipient>
# or
smtp://<smtp-host>:<port>/<recipient>

# Example
dewy server --registry ghr://owner/repo \
  --notifier mail://smtp.gmail.com:587/admin@example.com \
  -- /opt/myapp/current/myapp

Environment variables

# SMTP authentication info
export MAIL_USERNAME=sender@gmail.com
export MAIL_PASSWORD=app-specific-password
export MAIL_FROM=sender@gmail.com

Configuration Options

URL Format Configuration

# Specify all settings with URL parameters
dewy server --registry ghr://owner/repo \
  --notifier "mail://smtp.gmail.com:587/admin@example.com?username=sender@gmail.com&password=app-password&from=sender@gmail.com&subject=Deploy+Notification"

Gmail Configuration Example

# Use environment variables
export MAIL_USERNAME=sender@gmail.com
export MAIL_PASSWORD=your-app-password
export MAIL_FROM=sender@gmail.com

# Execute Dewy
dewy server --registry ghr://owner/repo \
  --notifier "mail://smtp.gmail.com:587/admin@example.com?subject=MyApp+Deploy"

Error Notification Limits

Dewy limits consecutive error notifications to prevent spam.

• Limit start: After 3 consecutive errors, notifications are suppressed
• Limit release: Automatically released when normal operation resumes
• Behavior during limits: Logs are recorded but notifications are not sent

Multiple Environment Notification Configuration

Environment-specific Channels

# Production environment
dewy server --registry ghr://owner/repo \
  --notifier "slack://prod-deploy?title=MyApp+Production"

# Staging environment
dewy server --registry "ghr://owner/repo?pre-release=true" \
  --notifier "slack://staging-deploy?title=MyApp+Staging"

# Development environment
dewy server --registry "ghr://owner/repo?pre-release=true" \
  --notifier "slack://dev-deploy?title=MyApp+Development"

Troubleshooting

Slack notifications not arriving

1. Check token

   # Test token
   curl -H "Authorization: Bearer $SLACK_TOKEN" \
     https://slack.com/api/auth.test
   

2. Check permissions
   • Are channels:join and chat:write set in Bot Token Scopes?
   • Is the App installed in the workspace?
3. Check channel name

   # For public channels, exclude #
   # ❌ slack://#deployments
   # ✅ slack://deployments
   
   # For private channels, invite Bot beforehand
   

Email notifications not sending

1. Check SMTP settings

   # Test SMTP server connection
   telnet smtp.gmail.com 587
   

2. Check authentication info

   # Check environment variables
   echo $MAIL_USERNAME
   echo $MAIL_FROM
   # Don't display password
   

3. Check TLS settings

   # Test with TLS disabled (not recommended)
   dewy server --registry ghr://owner/repo \
     --notifier "mail://smtp.example.com:25/admin@example.com?tls=false"
   

The notification feature enables sharing deployment status across teams and enables early problem detection and response. Build an efficient operational system with appropriate notification settings.