How to build Rails, Postgres, ElasticSearch development environment with Docker

Build a Rails 6 development environment using Docker. The goal is to do everything on Docker, from rails new to rails db: create. The actual code is uploaded to here.

environment

$ sw_vers
ProductName:	macOS
ProductVersion:	11.1
BuildVersion:	20C69
$ docker -v
Docker version 20.10.0, build 7287ab3
$ docker-compose -v
docker-compose version 1.27.4, build 40524192

1. Create a Rails application environment with Docker

First, create a file under the root of the project as shown below.

$ tree
.
├── Dockerfile
├── Gemfile
├── Gemfile.lock
└── docker-compose.yml

0 directories, 4 files

Create a Dockerfile

FROM ruby:2.7.2
RUN apt-get update && apt-get install -y --no-install-recommends build-essential libpq-dev nodejs \
  && rm -rf /var/lib/apt/lists/*
WORKDIR /myapp
COPY Gemfile /myapp/Gemfile
COPY Gemfile.lock /myapp/Gemfile.lock
RUN gem install bundler:2.0.2 && bundle install
COPY . /myapp

docker-compose.yml

docker-compose.yml

version: "3"
services:
  #Container for Elasticsearch
  elasticsearch:
    image: docker.elastic.co/elasticsearch/elasticsearch:7.10.1
    environment:
      - discovery.type=single-node
      - cluster.name=docker-cluster
      - bootstrap.memory_lock=true
      - "ES_JAVA_OPTS=-Xms512m -Xmx512m"
    ulimits:
      memlock:
        soft: -1
        hard: -1
    ports:
      - 9200:9200
    volumes:
      - esdata:/usr/share/elasticsearch/data
  #Container for Kibana
  kibana:
    #Match the version numbers of elasticsearch and kibana images
    image: docker.elastic.co/kibana/kibana:7.10.1
    ports:
      - 5601:5601
    depends_on:
      - elasticsearch
  #Container for Postgres
  db:
    image: postgres
    ports:
      - 5432:5432
    volumes:
      - pgdata:/var/lib/postgresql/data
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: password
  #Container for Rails
  rails:
    build: .
    command: bundle exec rails server -p 3000 -b '0.0.0.0'
    depends_on:
      - db
      - elasticsearch
    ports:
      - 3000:3000
    environment:
      DATABASE_HOST: db
    tty: true
    stdin_open: true
    volumes:
      #Abandon consistency with delegated and focus on performance
      - .:/myapp:delegated
#Volume used by elasticsearch and db
volumes:
  esdata:
  pgdata:

Gemfile

source 'https://rubygems.org'
git_source(:github) { |repo| "https://github.com/#{repo}.git" }

ruby '2.7.2'

gem 'rails', '~> 6.1.0'

Gemfile.lock

Gemfile.lock

#Sky

2. rails new

docker-compose run --rm rails rails new . --force --database=postgresql --skip-test --api

Optional points ----rm Since it is a one-time use of the container, it is discarded after execution. --rails new . Create a Rails application in the current directory ---- database = postgresql Specify Postgres for the database

3. Make DB settings

Modify it to the value set as the environment variable in dockr-compose.yml.

default: &default
  adapter: postgresql
  encoding: unicode
  # For details on connection pooling, see Rails configuration guide
  # https://guides.rubyonrails.org/configuring.html#database-pooling
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
	#Add user and password
  username: <%= ENV.fetch('POSTGRES_USER') { 'postgres' } %>
  password: <%= ENV.fetch('POSTGRES_PASSWORD') { 'password' } %>

development:
  <<: *default
  database: myapp_development
	#DATABASE set in rails container_Set HOST as host
  host: &development_host <%= ENV.fetch('DATABASE_HOST') { 'localhost' } %>
test:
  <<: *default
  database: myapp_test
	#Set up a host similar to development
  host: *development_host

4. Start and check

After building the image, start it and make sure each container is up.

docker-compose build
docker-compose up

Don't forget to create a DB.

docker-compose run --rm rails bundle exec rails db:create

Rails confirmation

If you access http: // localhost: 3000 and the following screen is displayed, it is successful.

Confirmation of Kibana

If you access http: // localhost: 5601 and the following screen is displayed, it is successful.

Check ElasticSearch

If you make a request with the Curl command and return a response that includes cluster and version information as shown below, it is successful.

-> $ curl -XGET http://localhost:9200/
{
  "name" : "36e3fc003013",
  "cluster_name" : "docker-cluster",
  "cluster_uuid" : "9U_MQqxLQ1adh3jHpxEfEA",
  "version" : {
    "number" : "7.10.1",
    "build_flavor" : "default",
    "build_type" : "docker",
    "build_hash" : "1c34507e66d7db1211f66f3513706fdf548736aa",
    "build_date" : "2020-12-05T01:00:33.671820Z",
    "build_snapshot" : false,
    "lucene_version" : "8.7.0",
    "minimum_wire_compatibility_version" : "6.8.0",
    "minimum_index_compatibility_version" : "6.0.0-beta1"
  },
  "tagline" : "You Know, for Search"
}

reference

--Book "Construction of cloud infrastructure docker from the basics" --Book "Elasticsearch Practical Guide" ―― Create a search function with Rails and Elasticsearch and try various things ―― Part 1: Create a sample application ―― Qiita -Move Elasticsearch + Kibana quickly with docker-compose --Qiita

Summary

Now that you have an environment where you can use ElasticSearch, which you use for business, even for individuals, it seems that you can use it easily. I'm not very familiar with Docker, but I think that Docker's power has improved a little by building an environment by combining various middleware and Rails.