Receiving PostgreSQL CSPG017 (User Exists) error.

Potential causes can be found below. Chef Support can offer a basic resolution for this, but troubleshooting connectivity issues for external datastores is out of scope of support.

One (or more) of the PostgreSQL predefined users already exists.

Possible Causes 

• The opscode_chef, ospcode_chef_ro, bifrost, bifrost_ro, oc_id, or oc_id_ro users already exist on the remote machine
• The postgresql['vip'] setting is configured to a remote host, but postgresql['external'] is not set to true, which causes the opscode_chef and ospcode_chef_ro users to be created before the machine is reconfigured, which will return a permissions error
• Existing, valid naming conflicts are present, where the users were created independently of the Chef server

• Run the following, if it is safe to do so, to update the user name that is specified in the error message:

  DROP ROLE "name-of-user";

  or change the name of the user by updating following settings in the chef-server.rb configuration file:

  oc_id['sql_user'] = 'alternative_username'
  oc_id['sql_ro_user'] = alternative_username_for_ro_access'
  opscode_erchef['sql_user'] = 'alternative_username'
  opscode_erchef['sql_ro_user'] = 'alternative_username_for_ro_access'
  oc_bifrost['sql_ro_user'] = 'alternative_username'
  oc_bifrost['sql_ro_user'] = 'alternative_username_for_ro_access'