Docker Compose Operator

Docker Compose Operator Skill

Stateless atomic operation to compile template compose definitions, resolve active environment parameter overlays, deploy/restart Docker containers or Swarm stacks safely, and monitor container execution logs to verify operational health.

Prerequisites

• container-manager-mcp — for initiating compose actions (up, down, ps, logs), deploying service stacks, and monitoring process readiness.

Steps

Step 1: compile_compose_manifest

Assemble the targeted deployment specifications and validate syntax and overrides:

• Locate the reference compose YAML file (e.g. docker-compose.yml or stack.yml) and its corresponding .env or configuration parameters.
• Substitute template variables, environment configuration keys, and host path references.
• Execute validation on the compiled compose syntax (e.g. verify YAML validity, check that image references are fully qualified, and check that required volume mounts exist on the host).
• Output parameters:
  • manifest_valid: Boolean indicating successful compilation.
  • resolved_manifest_path: Absolute path to the validated temporary compose file.

Step 2: execute_compose_deployment [depends_on: compile_compose_manifest]

Execute deployment operations with safety checks:

• Trigger container launch:
  • Invoke up or stack deploy operations via container-manager-mcp (e.g., using cm_compose_operations).
  • Pass the compiled configuration file and specify proper namespace/stack definitions.
• Coordinate dependencies and rolling replacements:
  • Verify if pre-requisite backing databases or network subnets are operational before launching core app containers.
  • Enforce graceful termination timeouts for old container replicas to prevent socket drops.
• Output parameters:
  • deployment_exit_code: Int process return code.
  • deployment_raw_output: String command outputs.

Step 3: verify_operational_health [depends_on: execute_compose_deployment]

Perform granular verification of the active containers to ensure readiness and stability:

• Poll container states:
  • Wait for containers to exit boot phases, querying runtime statuses (running, healthy, restarting).
• Log inspection and error parsing:
  • Retrieve and parse container stdout/stderr logs (e.g. using get_container_logs action).
  • Scan for common startup exceptions (e.g., ConnectionRefusedError, Database error, Exception).
• readiness probes:
  • If web ports or health check endpoints are mapped, test their accessibility (expecting standard 200 OK or valid TCP socket connections).
• Output parameters:
  • status: "SUCCESS" or "FAILED"
  • active_containers: List of running service instances with their states.
  • health_log_summary: Summary of any anomalies or startup errors discovered.