docker and docker compose support

Add Docker and Docker Compose support by adding `Dockerfile`s and a
`docker-compose.yml`.

The Docker setup is a little different for React/Webpacker apps and
standard Rails app, so different files are copied depending on whether
run with `--webpack=react` or not.

Author: zfletch

README.md

@@ -51,6 +51,30 @@ $ bin/yarn test
   - Add Variable.
   - Name the variable `PRONTO_GITHUB_ACCESS_TOKEN` with the value from the previous Personal Access Token.
 
+# Usage with Docker
+
+A `Dockerfile` and `docker-compose.yml` file are created by default. When run with `--webpack=react`,
+there are two `Dockerfile`s: one for the Rails server and one for the assets server.
+
+To use Docker, run:
+
+```sh
+docker-compose build
+```
+
+then set up the the database:
+
+```sh
+docker-compose run web rails db:create
+docker-compose run web rails db:migrate
+```
+
+finally, start the server and visit `localhost:3000`:
+
+```sh
+docker-compose up
+```
+
 # Switching out Capybara Driver
 If you'd like to not run your tests headless, for example, to troubleshoot an issue and see what's on the screen, modify the `Capybara.javascript_driver` in `spec/rails_helper.rb` to use `:chome` instead of `:headless_chrome`. After the change, this line should look as follows:
 

gnarly.rb

@@ -213,9 +213,24 @@ def modify_npm_scripts
     "Capybara.default_max_wait_time = 3\n"
 end
 
+react = options[:webpack] == "react"
+
+# Docker
+copy_file "templates/Dockerfile", "Dockerfile"
+
+if react
+  copy_file "templates/Dockerfile-assets", "Dockerfile-assets"
+  copy_file "templates/.env.docker/.env.docker-webpack", ".env.docker"
+  copy_file "templates/.env.docker-assets", ".env.docker-assets"
+  copy_file "templates/docker-compose.yml/docker-compose-webpack.yml", "docker-compose.yml"
+else
+  copy_file "templates/.env.docker/.env.docker-standard", ".env.docker"
+  copy_file "templates/docker-compose.yml/docker-compose-standard.yml", "docker-compose.yml"
+end
+
 # Retrieve all gems, set up git, display next steps
 after_bundle do
-  if options[:webpack] == "react"
+  if react
     install_js_deps
     add_js_files
     modify_npm_scripts

templates/.env.docker-assets

@@ -0,0 +1 @@
+WEBPACKER_DEV_SERVER_HOST=0.0.0.0

templates/.env.docker/.env.docker-standard

@@ -0,0 +1 @@
+DATABASE_HOST=db

templates/.env.docker/.env.docker-webpack

@@ -0,0 +1,2 @@
+DATABASE_HOST=db
+WEBPACKER_DEV_SERVER_HOST=assets

templates/Dockerfile

@@ -0,0 +1,20 @@
+FROM ruby:2.4.2
+
+# use a newer version of Node to use Yarn
+RUN curl -sL https://deb.nodesource.com/setup_8.x | bash -
+
+# nodejs: Rails needs a JS runtime
+# cmake: required by Rugged, dependency of Pronto
+RUN apt-get update -qq \
+    && apt-get install -y -qq nodejs cmake
+
+RUN npm install -g yarn
+
+RUN mkdir /app
+WORKDIR /app
+
+ADD Gemfile /app/Gemfile
+ADD Gemfile.lock /app/Gemfile.lock
+RUN bundle install
+
+ADD . /app

templates/Dockerfile-assets

@@ -0,0 +1,24 @@
+FROM ruby:2.4.2
+
+# use a newer version of Node to use Yarn
+RUN curl -sL https://deb.nodesource.com/setup_8.x | bash -
+
+# nodejs: Rails needs a JS runtime
+# cmake: required by Rugged, dependency of Pronto
+RUN apt-get update -qq \
+    && apt-get install -y -qq nodejs cmake
+
+RUN npm install -g yarn
+
+RUN mkdir /app
+WORKDIR /app
+
+ADD Gemfile /app/Gemfile
+ADD Gemfile.lock /app/Gemfile.lock
+RUN bundle install
+
+ADD package.json /app/package.json
+ADD yarn.lock /app/yarn.lock
+RUN yarn install
+
+ADD . /app

templates/docker-compose.yml/docker-compose-standard.yml

@@ -0,0 +1,15 @@
+version: '3'
+services:
+  db:
+    image: postgres
+  web:
+    build: .
+    command: bash -c 'rm -f tmp/pids/server.pid && bundle exec rails s --port 3000 --binding 0.0.0.0'
+    volumes:
+      - .:/app
+    ports:
+      - 3000:3000
+    depends_on:
+      - db
+    env_file:
+      - .env.docker

templates/docker-compose.yml/docker-compose-webpack.yml

@@ -0,0 +1,26 @@
+version: '3'
+services:
+  db:
+    image: postgres
+  assets:
+    build:
+      context: .
+      dockerfile: Dockerfile-assets
+    command: yarn start
+    volumes:
+      - .:/app
+      - /app/node_modules
+    env_file:
+      - .env.docker-assets
+  web:
+    build: .
+    command: bash -c 'rm -f tmp/pids/server.pid && bundle exec rails s --port 3000 --binding 0.0.0.0'
+    volumes:
+      - .:/app
+    ports:
+      - 3000:3000
+    depends_on:
+      - db
+      - assets
+    env_file:
+      - .env.docker