在 Docker Rails 中更改 Postgres 端口

Question

I would like to run the postgres on a different port from my local machine pointing to 5432 in docker container.

version: '3'
services:
 db:
  image: postgres:alpine
  restart: always
  volumes:
   - ./tmp/db:/var/lib/postgresql/data
  ports:
    - "9000:5432"
 web:
  build: .
  restart: always
  command: bash -c "rm -f tmp/pids/server.pid && rails s -p 3000 -b '0.0.0.0'"
  volumes:
   - .:/myapp
  ports:
   - "3002:3000"
  depends_on:
   - db

and in database.yml I'm pointing the development environment to port 9000

default: &default
  adapter: postgresql
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

development:
  <<: *default
  host: db
  username: postgres
  database: myapp_development
  port: 9000

test:
  <<: *default
  database: myapp_test

But when I run the rails app in localhost:3002 I'm getting

Could not connect to server: Connection refused Is the server running on host "db" (172.21.0.2) and accepting TCP/IP connections on port 9000?

Answer 1

you need to set your port to 5432 docker network will use the internal ports:

development:
  <<: *default
  host: db
  username: postgres
  database: myapp_development
  port: 5432