Agents

Agent Mode allows running Drydock in a distributed manner across multiple Docker hosts.

The Agent Mode allows running drydock in a distributed manner.

Agent Node: Runs near the Docker socket (or other container sources). It performs discovery and update checks.
Controller Node: The central instance. It manages its own local watchers AND connects to remote Agents. It aggregates containers from Agents, and handles persistence, UI, and Notifications.

Architecture

The Controller connects to one or more Agents via HTTP/HTTPS. The Agent pushes real-time updates (container changes, new versions found) to the Controller using Server-Sent Events (SSE).

Agent Configuration

To run drydock in Agent mode, start the application with the --agent command line flag.

Agent Environment Variables

Env var	Required	Description	Default
`DD_AGENT_SECRET`	🔴	Secret token for authentication (must match Controller configuration)
`DD_AGENT_SECRET_FILE`	⚪	Path to file containing the secret token
`DD_SERVER_PORT`	⚪	Port to listen on	`3000`
`DD_SERVER_TLS_*`	⚪	Standard Server TLS options
`DD_WATCHER_{name}_*`	🔴	Watcher configuration (At least one is required)
`DD_REGISTRY_{name}_*`	⚪	Registry configuration (For update checks)

Agent Example (Docker Compose)

services:
  drydock-agent:
    image: codeswhat/drydock
    command: --agent
    environment:
      - DD_AGENT_SECRET=mysecretkey
      - DD_WATCHER_LOCAL_SOCKET=/var/run/docker.sock
      - DD_LOG_LEVEL=debug
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock

Controller Configuration

To connect a Controller to an Agent, use the DD_AGENT_{name}_* environment variables.

Controller Environment Variables

Env var	Required	Description	Default
`DD_AGENT_{name}_SECRET`	🔴	Secret token to authenticate with the Agent
`DD_AGENT_{name}_SECRET_FILE`	⚪	Path to file containing the secret token
`DD_AGENT_{name}_HOST`	🔴	Hostname or IP of the Agent
`DD_AGENT_{name}_PORT`	⚪	Port of the Agent	`3000`
`DD_AGENT_{name}_CAFILE`	⚪	CA certificate path for TLS connection
`DD_AGENT_{name}_CERTFILE`	⚪	Client certificate path for TLS connection
`DD_AGENT_{name}_KEYFILE`	⚪	Client key path for TLS connection

Controller Example (Docker Compose)

services:
  drydock-controller:
    image: codeswhat/drydock
    environment:
      - DD_AGENT_REMOTE1_HOST=192.168.1.50
      - DD_AGENT_REMOTE1_SECRET=mysecretkey
    ports:
      - 3000:3000

Features in Agent Mode

Watchers: Run on the Agent to discover containers.
Registries: Configured on the Agent to check for updates.
Triggers:
- docker and dockercompose triggers are executed on the Agent (allowing update of remote containers).
- Notification triggers (e.g. smtp, discord) are executed on the Controller.

Agents

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