@deathbyjer I've updated the README with a few more steps as well as adding the instructions for setting up a test environment in case you wish to point people here in the future. I couldn't open a PR due to access restrictions. This should cover most places where I got stuck, but I may have missed a step or two. Later this week I'll try this again to ensure accuracy!

`Startup a Docker-Compose project with Rails

This is a quickly updated version of the startup portion from https://docs.docker.com/samples/rails/

Purpose

There has been confusion using the sample provided by docker-compose, so I resolved to provide an easy-to-use skeleton that can be quickly booted up.
The two main items I edited was bumping the Rails version to 6 and making the Dockerfile expecting the its directory to also be the Rails directory.

Steps

1. Clone this repo
2. Change folder name to the name of the app you wish to create.
3. Within Dockerfile be sure to replace all instances of myapp with your intended application name.
4. Run docker-compose run --no-deps web rails new . --force --database=postgresql within the directory. (This will setup Rails)
5. Run docker-compose run --no-deps web chown -R 1000:1000 * (This will reset the permissioning on the generated files so you can work on them locally)
6. Run docker-compose build web (This will ensure that everything is appropriate built off the Rails-generated Gemfile
7. Run docker-compose up (to start the service!)
8. While that is running hit cmd+t (on mac, ctrl+t on widowns) in terminal to open a new terminal tab.
9. Within that tab run docker-compose run web rake db:create to create you docker db.

Be advised that some of these commands can take 3-7 minutes, depending on your system.

Testing Database Setup

If you wish to set up a database for docker as well as one for testing the following is recommended.
Again, making sure to replace myapp with your applications name!

1. Change docker-compose.yml to the following.

version: "3.9"
services:
  db:
    image: postgres
    volumes:
      - ./tmp/db:/var/lib/postgresql/data
    environment:
      POSTGRES_PASSWORD: password
  web:
    build: .
    command: bash -c "rm -f tmp/pids/server.pid && bundle exec rails s -p 3000 -b '0.0.0.0'"
    volumes:
      - .:/myapp
      - ./docker/database.yml:/myapp/config/database.yml #New directory for docker!
    ports:
      - "3000:3000"
    depends_on:
      - db

This will point docker towards one db and your tests towards another as to avoid any conflicts.

2. In config/database.yml copy and paste the following.

default: &default
  adapter: postgresql
  encoding: unicode
  host: localhost # Local db for testing
  username: postgres
  password: password
  pool: 5

development:
  <<: *default
  database: myapp_development


test:
  <<: *default
  database: myapp_test

3. Create your new docker folder in your main application directory and place the following database.yml.

default: &default
  adapter: postgresql
  encoding: unicode
  host: db #Local db for Docker
  username: postgres
  password: password
  pool: 5

development:
  <<: *default
  database: myapp_list_development


test:
  <<: *default
  database: myapp_list_test

4. Rerun docker-compose up.
   `