On my local computer, I run a seed task to my staging server, using bundle exec rake db:seed RAILS_ENV=staging. It gives me the following error:

bundle exec rake db:seed RAILS_ENV=staging
rake aborted!
Moped::Errors::ConnectionFailure: Could not connect to a primary node for replica set

<Moped::Cluster:70258359778560 @seeds=[<Moped::Node resolved_address="10.10.4.131:27017">]>

/Users/donato/.rvm/gems/ruby-2.1.2@core/gems/moped-2.0.4/lib/moped/cluster.rb:254:in `with_primary'

I am able to deploy to that server using capistrano. So I know it is not a networking issue. Furthermore, I have seed tasks to mysql on that same server, so I know it is not a networking problem. So why is mongoid raising this exception?