⚡ execute

⚡ execute

Run arbitrary shell commands on the target system.

⚡ Actions

📋 Attributes

💡 Common attributes user and cwd are especially useful with execute — run commands as a specific user or in a specific directory.

🔍 How It Works

1. Evaluate guards — only_if/not_if commands run first to decide if the resource should execute
2. Run command — Executes the command on the target system
3. Always marks as changed — Every successful execution is considered an update (calls updated!)

⚠️ Important: Because execute always marks itself as changed, it will always trigger notifications. Use guards (not_if/only_if) to make execute resources idempotent.

🔬 Dry-Run Behavior

In dry-run mode, the command itself is skipped, but you see:

 INFO :   execute[apt-get update]
 INFO :     executed will change from 'false' to 'true'

⚠️ Guards (only_if/not_if) still run their commands in dry-run mode — this is necessary to determine whether the resource would execute.

📖 Examples

Basic command

execute 'apt-get update'

Named resource with explicit command

execute 'update package cache' do
  command 'apt-get update -qq'
end

Idempotent execution with guards 🛡️

execute 'create an empty file' do
  command 'touch /path/to/file'
  not_if 'test -e /path/to/file'
end

execute 'initialize database' do
  command '/opt/app/bin/db-init'
  only_if 'test -f /opt/app/bin/db-init'
  not_if 'test -f /opt/app/.db-initialized'
end

Run as a specific user

execute 'bundle install' do
  command 'cd /opt/app && bundle install --deployment'
  user 'deploy'
  cwd '/opt/app'
end

Used with notifications 🔔

execute 'compile assets' do
  action :nothing
  command 'cd /opt/app && rake assets:precompile'
end

git '/opt/app' do
  repository 'https://github.com/user/app.git'
  notifies :run, 'execute[compile assets]', :immediately
end

Run with error handling

execute 'optional cleanup' do
  command 'rm -rf /tmp/build-cache'
  only_if 'test -d /tmp/build-cache'
end