Berkshelf error log

gistfile1.txt

  1 Generated at 2015-03-31 21:19:29 +0900
  2 Chef::Exceptions::PrivateKeyMissing: I cannot read /etc/chef/validation.pem, which you told me to use to sign requests!
  3 /usr/lib/ruby/vendor_ruby/chef/http/authenticator.rb:78:in `rescue in load_signing_key'
  4 /usr/lib/ruby/vendor_ruby/chef/http/authenticator.rb:68:in `load_signing_key'
  5 /usr/lib/ruby/vendor_ruby/chef/http/authenticator.rb:38:in `initialize'
  6 /usr/lib/ruby/vendor_ruby/chef/rest.rb:66:in `new'
  7 /usr/lib/ruby/vendor_ruby/chef/rest.rb:66:in `initialize'
  8 /usr/lib/ruby/vendor_ruby/chef/api_client/registration.rb:125:in `new'
  9 /usr/lib/ruby/vendor_ruby/chef/api_client/registration.rb:125:in `http_api'
 10 /usr/lib/ruby/vendor_ruby/chef/api_client/registration.rb:92:in `create'
 11 /usr/lib/ruby/vendor_ruby/chef/api_client/registration.rb:83:in `create_or_update'
 12 /usr/lib/ruby/vendor_ruby/chef/api_client/registration.rb:56:in `run'
 13 /usr/lib/ruby/vendor_ruby/chef/client.rb:323:in `register'
 14 /usr/lib/ruby/vendor_ruby/chef/client.rb:416:in `do_run'
 15 /usr/lib/ruby/vendor_ruby/chef/client.rb:213:in `block in run'
 16 /usr/lib/ruby/vendor_ruby/chef/client.rb:207:in `fork'
 17 /usr/lib/ruby/vendor_ruby/chef/client.rb:207:in `run'
 18 /usr/lib/ruby/vendor_ruby/chef/application.rb:217:in `run_chef_client'
 19 /usr/lib/ruby/vendor_ruby/chef/application/client.rb:328:in `block in run_application'
 20 /usr/lib/ruby/vendor_ruby/chef/application/client.rb:317:in `loop'
 21 /usr/lib/ruby/vendor_ruby/chef/application/client.rb:317:in `run_application'
 22 /usr/lib/ruby/vendor_ruby/chef/application.rb:67:in `run'
 23 /usr/bin/chef-client:25:in `<main>'