```ruby
#
# Cookbook Name:: resolver
# Recipe:: default
#
# Copyright 2009, Opscode, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# = Requires
# * node[:resolver][:nameservers]

template "/etc/resolv.conf" do
  source "resolv.conf.erb"
  owner "root"
  group "root"
  mode 0644
end
```

Make the resolver cookbook fail if the nameservers attribute is empty
user
```ruby
#
# Cookbook Name:: resolver
# Recipe:: default
#
# Copyright 2009, Opscode, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# = Requires
# * node[:resolver][:nameservers]

if node[:resolver][:nameservers] == [ "" ]
  Chef::Log.info("nameservers attribute not set for the resolver cookbook.  Exiting so we don't break name resolution on the node")
  exit(true)
else
  template "/etc/resolv.conf" do
    source "resolv.conf.erb"
    owner "root"
    group "root"
    mode 0644
  end
end
```
assistant