gistfile1.txt

file "/etc/apt/sources.list.d/my-ppa.list" do
  content "deb http://ppa.launchpad.net/USER/ppa/ubuntu lucid main"
  owner "root"
  group "root"
  mode 0644
end

execute "Add PPA key" do
  command "apt-key adv --keyserver keyserver.ubuntu.com --recv-keys KEY"
  not_if "apt-key list | grep -xq '.*1024R/KEY.*'"
end

execute "apt-get update" do
  action :nothing
  subscribes :run, resources(:execute => "Add PPA key"), :immediately
  subscribes :run, resources(:file => "/etc/apt/sources.list.d/my-ppa.list"), :immediately
end