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# プロジェクト作成
rails new echo_task --database=postgresql --css=tailwind
cd echo_task
 
# コアモデルの生成
rails generate model User email:string:uniq name:string password_digest:string
rails generate model Task title:string description:text status:integer user:references due_date:date
rails generate model Comment body:text task:references user:references
 
# マイグレーション実行
rails db:create db:migrate

# db/schema.rb (抜粋)
ActiveRecord::Schema[7.1].define(version: 2024_03_15_000001) do
  enable_extension "plpgsql"
 
  create_table "users", force: :cascade do |t|
    t.string   "email",           null: false
    t.string   "name",            null: false
    t.string   "password_digest", null: false
    t.datetime "created_at",      null: false
    t.datetime "updated_at",      null: false
    t.index ["email"], name: "index_users_on_email", unique: true
  end
 
  create_table "tasks", force: :cascade do |t|
    t.string   "title",       null: false
    t.text     "description"
    t.integer  "status",      default: 0, null: false
    t.bigint   "user_id",     null: false
    t.date     "due_date"
    t.datetime "created_at",  null: false
    t.datetime "updated_at",  null: false
    t.index ["user_id"], name: "index_tasks_on_user_id"
    t.index ["status"],  name: "index_tasks_on_status"
  end
 
  add_foreign_key "tasks", "users"
end

# app/models/user.rb
class User < ApplicationRecord
  has_secure_password
  has_many :tasks, dependent: :destroy
  has_many :comments, dependent: :destroy
 
  validates :email, presence: true, uniqueness: { case_sensitive: false },
                    format: { with: URI::MailTo::EMAIL_REGEXP }
  validates :name, presence: true, length: { maximum: 50 }
 
  before_save { self.email = email.downcase }
end

# app/models/task.rb
class Task < ApplicationRecord
  belongs_to :user
  has_many :comments, dependent: :destroy
 
  validates :title, presence: true, length: { maximum: 100 }
  enum :status, { pending: 0, in_progress: 1, completed: 2, archived: 3 }
 
  scope :active,    -> { where(status: [:pending, :in_progress]) }
  scope :overdue,   -> { active.where("due_date < ?", Date.current) }
  scope :due_today, -> { active.where(due_date: Date.current) }
 
  def overdue?
    due_date.present? && due_date < Date.current && !completed?
  end
end

# config/routes.rb
Rails.application.routes.draw do
  root "dashboard#index"
 
  resource  :session,  only: [:new, :create, :destroy]
  resources :users,    only: [:new, :create]
  resources :tasks do
    resources :comments, only: [:create, :destroy]
    member do
      patch :complete
      patch :archive
    end
  end
end

# app/controllers/tasks_controller.rb
class TasksController < ApplicationController
  before_action :authenticate_user!
  before_action :set_task, only: [:show, :edit, :update, :destroy, :complete, :archive]
 
  def index
    @tasks = Current.user.tasks.active.order(due_date: :asc, created_at: :desc)
  end
 
  def create
    @task = Current.user.tasks.new(task_params)
    if @task.save
      redirect_to @task, notice: "タスクを作成しました"
    else
      render :new, status: :unprocessable_entity
    end
  end
 
  def complete
    @task.completed!
    redirect_to tasks_path, notice: "タスクを完了しました"
  end
 
  private
 
  def set_task
    @task = Current.user.tasks.find(params[:id])
  end
 
  def task_params
    params.require(:task).permit(:title, :description, :due_date)
  end
end

# /etc/nginx/sites-available/echo_task
upstream echo_task {
    server unix:///var/www/echo_task/shared/tmp/sockets/puma.sock fail_timeout=0;
}
 
server {
    listen 80;
    listen [::]:80;
    server_name echotask.app www.echotask.app;
 
    # HTTPSへリダイレクト
    return 301 https://$host$request_uri;
}
 
server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name echotask.app www.echotask.app;
 
    ssl_certificate     /etc/letsencrypt/live/echotask.app/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/echotask.app/privkey.pem;
    ssl_protocols       TLSv1.2 TLSv1.3;
    ssl_ciphers         HIGH:!aNULL:!MD5;
 
    # ワーカープロセス数（CPUコア数に合わせる）
    worker_processes    auto;
 
    # リクエストタイムアウト
    proxy_connect_timeout 60s;
    proxy_read_timeout    60s;
    proxy_send_timeout    60s;
 
    root /var/www/echo_task/current/public;
    client_max_body_size 10m;
 
    # 静的ファイルはNginxが直接返す（Pumaを通さない）
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2)$ {
        expires     1y;
        add_header  Cache-Control "public, immutable";
        gzip_static on;
    }
 
    # Railsへのプロキシ
    location / {
        proxy_pass         http://echo_task;
        proxy_set_header   Host              $host;
        proxy_set_header   X-Real-IP         $remote_addr;
        proxy_set_header   X-Forwarded-For   $proxy_add_x_forwarded_for;
        proxy_set_header   X-Forwarded-Proto $scheme;
        proxy_redirect     off;
    }
}

# config/puma.rb
max_threads_count = ENV.fetch("RAILS_MAX_THREADS") { 5 }
min_threads_count = ENV.fetch("RAILS_MIN_THREADS") { max_threads_count }
threads min_threads_count, max_threads_count
 
# ワーカーは0（シングルプロセス）で始める
# 1 vCPU のVPSでは複数ワーカーはメモリ不足になる
workers ENV.fetch("WEB_CONCURRENCY") { 0 }
 
port        ENV.fetch("PORT") { 3000 }
environment ENV.fetch("RAILS_ENV") { "development" }
 
# ソケット経由でNginxと接続
bind "unix:///var/www/echo_task/shared/tmp/sockets/puma.sock"
 
pidfile     ENV.fetch("PIDFILE") { "tmp/pids/server.pid" }
plugin :tmp_restart

# config/deploy.rb
lock "~> 3.17"
 
set :application,    "echo_task"
set :repo_url,       "git@github.com:haruto/echo_task.git"
set :deploy_to,      "/var/www/echo_task"
set :branch,         :main
set :linked_files,   %w[.env]
set :linked_dirs,    %w[log tmp/pids tmp/cache tmp/sockets storage]
set :keep_releases,  5
 
namespace :deploy do
  after :finishing, :restart do
    invoke "puma:restart"
  end
end

$ ssh deploy@203.0.113.10
Last login: Sun Jun 16 23:41:02 2024
 
$ uptime
 06:58:01 up 92 days,  7:22,  1 user,
 load average: 28.4, 26.1, 22.7

$ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/sda1        25G   24G  580M  98% /
tmpfs           489M  4.0K  489M   1% /dev/shm

$ ls -lh /var/www/echo_task/shared/log/
-rw-r--r-- 1 deploy deploy 8.7G Jun 17 06:55 production.log

$ psql echo_task_production -c "SELECT count(*) FROM pg_stat_activity WHERE state = 'active';"
 count
-------
   497
(1 row)

$ tail -n 50 /var/www/echo_task/shared/log/production.log
...
PG::ConnectionBad: FATAL:  sorry, too many clients already
PG::ConnectionBad: FATAL:  sorry, too many clients already
ActiveRecord::StatementInvalid: PG::ConnectionBad: FATAL: sorry, too many clients already
  app/controllers/tasks_controller.rb:8:in `index'
...