Gemfile

Comprehensive Gemfile guide for Ruby bots and web (site/API) applications on Discloud.

🗂️ What is Gemfile?

Gemfile lists the gems (libraries) your Ruby application needs. Discloud uses Bundler during deployment to install them before starting your app.

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🛠️ Creating a Gemfile (Quick Start)

1

Initialize Bundler in an empty folder:

bundle init

This creates a starter Gemfile.

2

Add dependencies directly via Bundler:

bundle add sinatra
bundle add puma

3

Install (respecting the Gemfile):

bundle install

Install Bundler if missing: gem install bundler.

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🧪 Environment Groups

group :development, :test do
	gem 'pry'
	gem 'rspec'
end

group :production do
	# production-only gems (APM, logging backends, etc.)
end

Skip installing dev/test groups at deploy time if desired:

bundle install --without development test

---

🧩 Example Gemfiles

Rails (Site/API)

Gemfile

source 'https://rubygems.org'

ruby '3.2.2'

gem 'rails', '~> 7.0.0'
gem 'puma',  '~> 5.0'
gem 'pg',    '~> 1.1'   # or 'sqlite3' for simple/local usage
gem 'bootsnap', '>= 1.4.4', require: false

group :development, :test do
	gem 'pry'
	gem 'rspec-rails'
end

group :production do
	# monitoring / caching / etc.
end

gem 'bundler', '~> 2.4'

Sinatra (Site/API)

Gemfile

source 'https://rubygems.org'
ruby '3.2.2'

gem 'sinatra', '~> 3.0'
gem 'puma',    '~> 5.0'
gem 'dotenv',  '~> 2.8', require: false

group :development do
	gem 'rerun'
end

discordrb (Bot)

Gemfile

source 'https://rubygems.org'
ruby '3.2.2'

gem 'discordrb', '~> 3.4'
gem 'dotenv',    '~> 2.8', require: false

group :development do
	gem 'pry'
end

Minimal Bot

Gemfile

source 'https://rubygems.org'
ruby '3.2.2'

# Add only what you truly need
gem 'httparty', '~> 0.21'

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🧾 Sample config.ru (Sinatra / Rack Site)

config.ru

require 'bundler/setup'
require 'sinatra'
require 'dotenv/load' if ENV['RACK_ENV'] != 'production'

set :bind, '0.0.0.0'
set :port, (ENV['PORT'] || 8080)

get '/' do
	'Hello from Discloud Sinatra app!'
end

run Sinatra::Application

For bots you typically do NOT need config.ru; instead just point MAIN in discloud.config to your Ruby entry (e.g. bot.rb).

---

🧪 Updating Dependencies

# Update a single gem
bundle update puma

# Update all (careful – may introduce breaking changes)
bundle update

# See outdated gems
bundle outdated

Security patches: monitor advisories (e.g., RubySec / Dependabot) and schedule periodic bundle update --patch.

---

🧰 Common Commands Reference

# Initialize Gemfile
bundle init

# Add gem (writes Gemfile & installs)
bundle add <gem>

# Install with production-only groups
bundle install --without development test

# Check dependency graph issues
bundle check

# Clean unused gems (after prune)
bundle clean --force