Description of problem:
Run etcd scale-up playbook but failed as below:

TASK [etcd : Add new etcd members to cluster] *******************************************************************************************************************************
fatal: [ec2-34-207-200-174.compute-1.amazonaws.com]: FAILED! => {"failed": true, "msg": "The task includes an option with an undefined variable. The error was: 'dict object' has no attribute 'etcd_ip'\n\nThe error appears to have been in '/usr/share/ansible/openshift-ansible/roles/etcd/tasks/add_new_member.yml': line 5, column 3, but may\nbe elsewhere in the file depending on the exact syntax problem.\n\nThe offending line appears to be:\n\n\n- name: Add new etcd members to cluster\n  ^ here\n\nexception type: <class 'ansible.errors.AnsibleUndefinedVariable'>\nexception: 'dict object' has no attribute 'etcd_ip'"}


Version-Release number of the following components:
openshift-ansible-3.10.0-0.60.0.git.0.bf95bf8.el7.noarch

How reproducible:
Always


Steps to Reproduce:
1.Add [new_etcd] group in the inventory file, run etcd scale-up playbook
#ansible-playbook -i 310_scale_etcd /usr/share/ansible/openshift-ansible/playbooks/openshift-etcd/scaleup.yml -v


Actual results:
Please include the entire output from the last TASK line through the end of output if an error is generated

Expected results:

Additional info:
Please attach logs from ansible-playbook with the -vvv flag