DO is a Ruby gem providing a clean, chainable DSL for executing commands and managing files over SSH on remote Linux servers.
Server Connection
require 'do'
# Initialize connection with SSH key authentication
server = DO::Server.new('srv1', 'node1.example.com', 'root', key: ['~/.ssh/id_rsa'])
Executing Commands
# Single command
output = server.run 'uname -a'
# Multiple command arguments
server.run 'apt-get', 'update', '-y'
# Commands with stdin prompt responses
server.run 'passwd user', 'newpassword', 'newpassword'
File Inspection & Transfers
# Check file existence
server.exist?('/etc/nginx/nginx.conf') # → true / false
# Read remote file contents
content = server.read('/etc/os-release')
# Upload local file to remote server
server.upload('/local/app.tar.gz', '/var/www/app.tar.gz')
# Download remote file to local disk
server.download('/var/log/nginx/access.log', './logs/access.log')
Remote Content Manipulation
# Replace entire content
server.replace :all, 'new configuration text', '/etc/app/config.env'
# Regex replacement
server.replace /^PORT=\d+$/, 'PORT=8080', '/etc/app/config.env'
# Append content (to bottom by default, or to top)
server.append 'export PATH=$PATH:/opt/bin', '~/.bashrc'
server.append '# Autogenerated File', '/etc/motd', :top
Interactive Prompts
# Prompt user for input
answer = server.ask 'Enter deployment tag:'
# Yes/No confirmation
if server.yes? 'Do you want to run database migrations?'
server.run 'bundle exec rake db:migrate'
end
# Wait for enter
server.wait