Localhost not found even if my docker containers are up?

I am relatively new to dev in general, to the Docker universe and to Rails in particular, apologize in advance if it sounds like a silly question.

I am trying to run an application in a monorepo composed of 4 services (2 websites and 2 APIs) + Postgresql, with the help of Docker Compose. The final goal is to run it on a VPS with Traefik (once I get the current app to work locally).

Here are the different services :

• Postgres (through the Postgres image available in Dockerhub)

• a B2C website (NextJS)

• an admin website (React with create Vite)

• an API (Rails). It should be linked to the Postgres database

• a Strapi API (for the content of the B2C website). Strapi has its own SQLite database. Only the B2C website requires the data coming from Strapi.

When I run the docker compose up -d command, it seems to be working (see pic below)

but when I go to one of the websites (except for the Strapi that seems to be correctly working) (https://localhost:3009, or 3008 or 3001), I get nothing (see below).

However, I don’t see any error in the logs of any apps. For instance the Rails API logs below:

I assume that I have mistakes in my config, especially in the database.yml config of the Rails api and the docker-compose.yml file.

database.yml :

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

development:
  <<: *default
  database: chana_api_v2_development

test:
  <<: *default
  database: chana_api_v2_test

production:
  <<: *default
  database: chana_api_v2_production
  username: chana
  password: <%= ENV["CHANA_DATABASE_PASSWORD"] %>

docker-compose.yml

version: '3'
services:
# ----------------POSTGRES -----------------
  pg:
    image: postgres:14.6
    container_name: pg
    networks:
      - chana_postgres_network
    ports:
      - "5432:5432"
    environment:
      POSTGRES_DB: chana_development
      POSTGRES_USER: chana
      POSTGRES_PASSWORD: chana
    volumes:
      - ./data:/var/lib/postgresql/data

# ----------------- RAILS API -----------------
  api:
    build: ./api
    container_name: api
    networks:
      - chana_postgres_network
      - api_network
    volumes:
      - ./api:/chana_api
    ports:
      - "3001:3000"
    depends_on:
      - pg

# ----------------- STRAPI -----------------
  strapi:
    build:
      context: ./strapi
      args:
        BASE_VERSION: latest
        STRAPI_VERSION: 4.5.0
    container_name: chana-strapi
    restart: unless-stopped
    env_file: .env
    environment:
      NODE_ENV: ${NODE_ENV}
      HOST: ${HOST}
      PORT: ${PORT}
    volumes:
      - ./strapi:/srv/app
      - strapi_node_modules:/srv/app/node_modules
    ports:
      - "1337:1337"

  # ----------------- B2C website -----------------
  public-front: 
    build: ./public-front
    container_name: public-front
    restart: always
    command: yarn dev
    ports:
      - "3009:3000"
    networks: 
      - api_network
      - chana_postgres_network
    depends_on:
      - api
      - strapi
    volumes:
      - ./public-front:/app
      - /app/node_modules
      - /app/.next

  # ----------------- ADMIN website -----------------
  admin-front: 
    build: ./admin-front
    container_name: admin-front
    restart: always
    command: yarn dev
    ports:
      - "3008:3000"
    networks: 
      - api_network
      - chana_postgres_network
    depends_on:
      - api
    volumes:
      - ./admin-front:/app
      - /app/node_modules
      - /app/.next

volumes:
  strapi_node_modules:

networks:
  api_network:
  chana_postgres_network:

Do you have any idea why I cannot see anything on the website pages?

I tried to change the code of the different files that are relevant, especially database.yml, docker-compose.yml, and the dockerfiles of each app.

Also, I tried to look into the api container (Rails) with the command docker exec -it api /bin/sh to check the database through the Rails console, and I get this error message:

activeRecord::ConnectionNotEstablished could not connect to server: No such file or directory. Is the server running locally and accepting connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?