Appendix E. Installation failure on Ansible step "Add masters to requisite groups"

An issue can occur if another stack uses the EC2 tag of openshift_role but does not have an EC2 tag KubernetesCluster. One possible work-around is to limit the regions that will be queried by the dynamic inventory script.

Modify regions = all to reflect a specific region.

# vi openshift-ansible-contrib/reference-architecture/aws-ansible/inventory/aws/hosts/ec2.ini
regions = us-east-1

Another option would be to temporarily stop the other instances until the installation is completed.