Docker+Traefik环境下Node TS应用VS Code调试连接失败求助

The ECONNREFUSED error occurs because your Node app's debug port (9229) wasn't properly exposed to your host machine, and the existing port mapping in your docker-compose file pointed to Traefik instead of your core service. Here's how to resolve this step-by-step:

Step 1: Correct Docker Compose Port Mapping #

Update your docker-compose.yml to map the host's 9229 port to your core service's debug port, and remove the unnecessary Traefik port mapping:

version: '3'
services:
  traefik:
    image: traefik:1.7
    command: --docker --docker.exposedbydefault=false
    ports:
      - '80:80'  # Remove the 9229:9229 line here
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
  core:
    image: node:alpine
    labels:
      - traefik.enable=true
      - traefik.port=4001
      - traefik.backend=core
      - traefik.frontend.rule=Host:core.localhost
    volumes:
      - ./leav_core:/app
    working_dir: /app
    command: [sh, -c, 'npm start']
    expose:
      - '9229'
    ports:
      - "9229:9229"  # Add this line to map host port 9229 to container's 9229
volumes:
  arango_data:
    driver: local

Why this change? #

• The original 9229:9229 entry in Traefik's ports was forwarding your host's port 9229 to Traefik (which doesn't use this port for debugging), not your Node app.
• Adding ports: - "9229:9229" to the core service exposes the container's debug port directly to your host, allowing VS Code to connect to it.

Step 2: Update VS Code Debug Configuration #

Refine your .vscode/launch.json to clarify connection details and improve path mapping:

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Docker: Attach to Node",
      "type": "node",
      "request": "attach",
      "port": 9229,
      "address": "localhost",
      "remoteRoot": "/app",
      "localRoot": "${workspaceFolder}/leav_core", // Maps local code to remote container path
      "skipFiles": [
        "<node_internals>/**" // Skips Node.js internal files during debugging
      ]
    }
  ]
}

Key improvements: #

• localRoot ensures VS Code correctly maps your local leav_core directory to the /app directory in the container, so breakpoints work as expected.
• Explicit port and address remove ambiguity about where the debugger should connect.

Step 3: (Optional) Pause App for Debugger Attachment #

If your app starts too quickly before the debugger can attach, modify your npm start command to use --inspect-brk instead of --inspect:

// In your package.json
"scripts": {
  "start": "ts-node --inspect-brk=0.0.0.0:9229 --type-check src/"
}

This will pause the app immediately after starting, waiting for the debugger to connect before executing any code.

Step 4: Restart Containers and Attach Debugger #

1. Stop your running containers: docker-compose down
2. Start them again: docker-compose up -d
3. In VS Code, select the "Docker: Attach to Node" configuration and click the debug play button.

You should now be able to set breakpoints and debug your Node app running in Docker, while still accessing it via http://core.localhost through Traefik.

内容的提问来源于stack exchange，提问作者Tdy