Setting homepage with Puppet16. Sep '15

You can use following Puppet snippet to set the URL opened by default. Mozilla Firefox and Chromium were rather undocumented and the examples on the Internet were outdated:

# Set Mozilla Firefox homepage
file_line { "firefox-homepage":
    path => "/etc/firefox/syspref.js",
    ensure => present,
    match => '^user_pref\("browser\.startup\.homepage",',
    line => 'user_pref("browser.startup.homepage", "");'

# Set Chromium homepage
file { "/etc/chromium-browser/policies/recommended/homepage.json":
  ensure => file,
  mode => 644,
  owner => root,
  group => root,
  content => "{\n  \"RestoreOnStartup\":4, \"RestoreOnStartupURLs\":[\"\"]\n}\n"

Note that on your Puppetmaster you might have to install additional module:

puppet module install puppetlabs-stdlib
Firefox Puppet Chromium