💻 local_ruby_block

💻 local_ruby_block

Execute arbitrary Ruby code on the local machine (where Itamae runs), not on the target. Useful for local logic, logging, or dynamic recipe behavior.

⚡ Actions

📋 Attributes

💡 This resource has no default_name attribute — the resource name is just a label for logging purposes.

🔍 How It Works

1. Execute — Calls the Ruby block on the local machine
2. CWD support — If the common cwd attribute is set, changes directory via Dir.chdir(cwd) before executing the block
3. Local context — The block runs in the Itamae process, with access to run_command for executing shell commands on the target

🔬 Dry-Run Behavior

⚠️ Important: The Ruby block is not executed in dry-run mode. The block is inside the action_run method, which is skipped entirely. There is no way to preview what a local_ruby_block would do.

📖 Examples

Run local logic

local_ruby_block 'print info' do
  block do
    puts 'Recipe is running!'
  end
end

Dynamic decisions 🔀

local_ruby_block 'check environment' do
  block do
    result = run_command('uname -r')
    Itamae.logger.info "Kernel: #{result.stdout.strip}"
  end
end

Conditional resource execution

local_ruby_block 'setup feature flag' do
  block do
    result = run_command('cat /etc/feature-flags.json')
    $enable_monitoring = result.stdout.include?('"monitoring": true')
  end
end

package 'prometheus-node-exporter' do
  only_if { $enable_monitoring }
end

Logging and debugging 🐛

local_ruby_block 'debug info' do
  block do
    Itamae.logger.info "Node attributes: #{node.to_hash}"
    Itamae.logger.info "Running on: #{run_command('hostname').stdout.strip}"
  end
end