How to modify a SSH configuration file using a puppet module

Question

I am trying to modify a SSH configuration file to remove the arcfour , arcfour 128 and arcfour 256 algorithms in the /etc/ssh/sshd_config on 186 linux servers using puppet. Basically, I am doing a find and replace to remove those three algorithm types in the sshd_config file. I created a module called SSH_Test and am wondering what my next steps would be. I think I can use these resources, but I am unsure where to put them, and I am not sure if they are right

file_line { 'Ciphers':
  path  => '/etc/ssh/sshd_config',
  line  => 'arcfour, arcfour128, arcfour256',
  match => '',
}

New configuration from below comment

node default { 
  file { '/etc/motd':
    owner => 'root',
    group => 'root',
    mode => '0644',
    content => "\nAll hail the knife crab\n"
  }
}

Answer 1

Following the documentation for file_line provided here: https://forge.puppet.com/puppetlabs/stdlib/types

we have the following resource:

file_line { 'Ciphers':
  ensure            => absent,
  path              => '/etc/ssh/sshd_config',
  match             => '.*arcfour.*',
  multiple          => true,
  match_for_absence => true,
}

ensure to remove the line, path for the specified file, match for the lines to match with a regexp, multiple because you want this to act on multiple lines in a file, and match_for_absence so that the lines are removed when matched.

If you are using Puppet >= 4.0, or 3.8 with the future parser, then this can be made more precise and cleaner with a lambda. Let me know if you are.