allow adding custom SSH known_hosts from a data bag

My use case for this is for adding github.com so I can clone a repo I
need

ssh_known_hosts/recipes/default.rb

@@ -23,6 +23,20 @@
 nodes = search(:node, "keys_ssh:* NOT name:#{node.name}")
 nodes << node
 
+other_hosts = data_bag('ssh_known_hosts')
+require 'resolv'
+r = Resolv.new
+other_hosts.each do |h|
+  host = data_bag_item('ssh_known_hosts', h)
+  host['ipaddress'] ||= r.getaddress(host['fqdn'])
+  host['keys'] = {
+    'ssh' => {}
+  }
+  host['keys']['ssh']['host_rsa_public'] = host['rsa'] if host.has_key?('rsa')
+  host['keys']['ssh']['host_dsa_public'] = host['dsa'] if host.has_key?('dsa')
+  nodes << host
+end
+
 template "/etc/ssh/ssh_known_hosts" do
   source "known_hosts.erb"
   mode 0444

ssh_known_hosts/templates/default/known_hosts.erb

@@ -1,5 +1,9 @@
 # THIS FILE IS MAINTAINED BY CHEF, DO NOT MODIFY AS IT WILL BE OVERWRITTEN
 <% @nodes.each do |n| -%>
-<%= n['hostname'] %>,<%= n['fqdn'] %>,<%= n['ipaddress'] %> ssh-rsa <%= n['keys']['ssh']['host_rsa_public'] %>
-<%= n['hostname'] %>,<%= n['fqdn'] %>,<%= n['ipaddress'] %> ssh-dsa <%= n['keys']['ssh']['host_dsa_public'] %>
+  <% if n['keys']['ssh'].has_key?('host_rsa_public') -%>
+<%= n.has_key?('hostname') ? "#{n['hostname']}," : '' %><%= n['fqdn'] %>,<%= n['ipaddress'] %> ssh-rsa <%= n['keys']['ssh']['host_rsa_public'] %>
+  <% end -%>
+  <% if n['keys']['ssh'].has_key?('host_dsa_public') -%>
+<%= n.has_key?('hostname') ? "#{n['hostname']}," : '' %><%= n['fqdn'] %>,<%= n['ipaddress'] %> ssh-dsa <%= n['keys']['ssh']['host_dsa_public'] %>
+  <% end -%>
 <% end -%>