CODEWITHSUNDEEP
node.jsdockerdocker-composenode-inspector
tnrich
tnrich

Reputation: 8610

Node-inspector in docker container using docker-compose

I feel like I am close to getting docker-compose and node-inspector playing nicely together but would love if someone could show me how they set up their docker-compose file along with an explanation for how it works.

Here's what my compose.yml file looks like with just the node app in it:

  app:
    image: my-node-app
    volumes:
     - '~/mycode:/app/code'
    ports:
     - "3000:3000"
    command: /bin/bash

Also note I'm using Docker for Mac. (Although I don't think that should change much..)

I found a couple tutorials for getting for how to do it, but the information was either out of date or seemed incomplete. Here are the two main approaches (neither has worked for me yet):

1) From: https://github.com/seelio/node-inspector-docker/issues/1

app:
    image: my-node-app
    ports:
     - "3000:3000"
    command: /bin/bash
    volumes_from:
     - code
debugger:
    image: node-debug
    depends_on: 
      - app
    # `service` instead of `container` for an easier cold start
    network_mode: 'service:app'
    volumes_from:
      - code
code:
    image: node
    volumes:
     - '~/mycode:/app/code'

2)

and from: https://keylocation.sg/our-tech/debugging-nodejs-in-docker-using-node-inspector : 

 debugger:
    container_name: debugger
    network_mode: host
    extends:
      service: base
    volumes:
      - /app/containers/debugger:/app/container

One little trick required was the addition of port 5858 mapping for the node-app container so that Node Inspector can see it as port 5858 on the host:

 node-app:
    ports:
      - "5858:5858" # Port needs to be mapped to host so that debugger container can access it

Upvotes: 1

Views: 1739

Answers (2)

Smar
Smar

Reputation: 8621

Node’s debug interface needs to know to be accessible outside of local network of Docker container, so the inspector should be started with

node --inspect-brk=0.0.0.0:9229 index.js

Replace index.js with whatever node thing you want to run.

--inspect-brk is used instead of --inspect so that debugger can be attached at start of the script, so that it can follow whatever it does, which allows the debugger to know whatever is happening, effectively allowing proper debugging.

The broadcast IP causes the inspector listen everything and not closing connections from outside of localhost (the default). 9229 is the default port.

Upvotes: 1

user3105486
user3105486

Reputation: 11

You have to add EXPOSE 5858 or EXPOSE 9229 in your app Dockerfile.

Upvotes: 1

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