node App not reachable from outside docker - node.js

Question

Im having troubles while trying to access my NodeJs app on a container.
Resume:
I customized my own image to run pm2 and loopback on my container.
I configured my app to listen to a mongodb on another container within a docker network. This works fine.
I created my docker-compose.yml file to looks like this:
version: '3.5'
services:
webapp:
expose:
- "3000"
ports:
- "3000:3000"
volumes:
- ${NODEJS_PATH}:${NODEJS_PATH_DESTIONATION}
image: ${CUSTOMIZED_IMAGE}
networks:
default:
ipv4_address: ${NODEJS_IP}
db:
image: mongo:4.2.6
container_name: mongodb
restart: always
environment:
MONGO_INITDB_ROOT_USERNAME: ${MONGO_INITDB_ROOT_USERNAME}
MONGO_INITDB_ROOT_PASSWORD: ${MONGO_INITDB_ROOT_PASSWORD}
MONGO_INITDB_DATABASE: ${MONGO_INITDB_DATABASE}
volumes:
- ${MONGO_SCRIPT_PATH}:${MONGO_SCRIPT_DESTINATION_PATH}
networks:
default:
ipv4_address: ${MONGO_INITDB_IP}
networks:
default:
external:
name: ${CUSTOMIZED_NET}
I ran my webapp with docker-compose run webapp for now for customize purposes.
Inside this container I execute the next cmd
pm2 start app.js --env environment_variables
It runs the NodeJS App on http://localhost:3000 inside the docker
I tried to check this from a browser http://{DOCKER_IP}:3000 but it's not working.
I would be eternally grateful with any answer to this trouble.

Answer 1

We used nginx to proxy_pass the service from the docker to the outside world.
We did it this way because we need other services on the docker_network to listen to this one.
Here is the config from the nginx
server {
listen 80;
server_name domain.local;
location / {
proxy_pass http://localhost:3000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
}