docker-compose and postgres basic rails app skeleton

Dockerfile

@@ -0,0 +1,17 @@
+# syntax=docker/dockerfile:1
+FROM ruby:2.7.0
+RUN apt-get update -qq && apt-get install -y nodejs postgresql-client
+WORKDIR /data_importer
+COPY Gemfile /data_importer/Gemfile
+COPY Gemfile.lock /data_importer/Gemfile.lock
+RUN bundle install
+
+# Add a script to be executed every time the container starts.
+COPY entrypoint.sh /usr/bin/
+RUN chmod +x /usr/bin/entrypoint.sh
+ENTRYPOINT ["entrypoint.sh"]
+EXPOSE 3000
+
+# Configure the main process to run when running the image
+CMD ["rails", "server", "-b", "0.0.0.0"]
+

Gemfile

@@ -5,8 +5,8 @@ ruby '2.7.0'
 
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '~> 5.2.3'
-# Use sqlite3 as the database for Active Record
-gem 'sqlite3'
+# Use postgres as the database for Active Record
+gem 'pg'
 # Use Puma as the app server
 gem 'puma', '~> 3.11'
 # Use SCSS for stylesheets

bin/docker_rebuild.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# docker rebuild and bundle install
+# updates Gemfile.lock
+
+docker-compose run web bundle install

config/database.yml

@@ -1,25 +1,17 @@
-# SQLite version 3.x
-#   gem install sqlite3
-#
-#   Ensure the SQLite 3 gem is defined in your Gemfile
-#   gem 'sqlite3'
-#
 default: &default
-  adapter: sqlite3
-  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
-  timeout: 5000
+  adapter: postgresql
+  encoding: unicode
+  host: db
+  username: postgres
+  password: password
+  pool: 5
 
 development:
   <<: *default
-  database: db/development.sqlite3
+  database: data_importer_development
+
 
-# Warning: The database defined as "test" will be erased and
-# re-generated from your development database when you run "rake".
-# Do not set this db to the same as development or production.
 test:
   <<: *default
-  database: db/test.sqlite3
+  database: data_importer_test
 
-production:
-  <<: *default
-  database: db/production.sqlite3

docker-compose.yml

@@ -0,0 +1,18 @@
+version: "3.3"
+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:
+      - .:/data_importer
+    ports:
+      - "3000:3000"
+    depends_on:
+      - db
+

entrypoint.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+set -e
+
+# Remove a potentially pre-existing server.pid for Rails.
+rm -f /myapp/tmp/pids/server.pid
+
+# Then exec the container's main process (what's set as CMD in the Dockerfile).
+exec "$@"
+