gistfile1.txt

chef resource
-------------
template "/path/to/credentials.json" do
  source 'credentials.json.erb'
  owner <user>
  group <user>
  mode '0400'
  variables({
    :private_key => private_key
  })
end



credentials.json.erb
--------------------
{
  "id": "site",
  "credentials": {
    "private_key": "<rsa_private_key>",
  }
}