User Input

User input can be required in a task or during configuration:

# used in a configuration
ask(:database_name, "default_database_name")

# used in a task
desc "Ask about breakfast"
task :breakfast do
  ask(:breakfast, "pancakes")
  on roles(:all) do |h|
    execute "echo \"$(whoami) wants #{fetch(:breakfast)} for breakfast!\""
  end
end

When using ask to get user input, you can pass echo: false to prevent the input from being displayed. This option should be used to ask the user for passwords and other sensitive data during a deploy run.

ask(:database_password, 'default_password', echo: false)

The symbol passed as a parameter will be printed as text for the user and the input will be saved to this variable:

ask(:database_encoding, 'UTF-8')
# Please enter :database_encoding (UTF-8):

fetch(:database_encoding)
# => contains the user input (or the default)
#    once the above line got executed

You can use ask to set a server- or role-specific configuration variable.

ask(:password, nil)
server 'example.com', user: 'ssh_user_name', port: 22, password: fetch(:password), roles: %w{web app db}

You can also show your own message by using prompt option:

  ask(:breakfast, "pancakes", prompt: "What's for breakfast?")

Important! ask will not prompt the user immediately. The question is deferred until the first time fetch is used to obtain the setting. That means you can ask for many variables, but only the variables used by your task(s) will actually prompt the user for input.