Installation fails when firewalld is enabled

IBM® Cloud Private installation on Red Hat Enterprise Linux™ (RHEL) 7 might fail if firewalld is enabled.

Symptoms

The installation fails with an error message that is similar to the following message:

TASK [iptables : Creating firewalld rules for Etcd] ****************************************************************************************************************************************************************************************
failed: [9.111.250.102] (item=4001) => {"failed": true, "item": 4001, "msg": "ERROR: Exception caught: org.fedoraproject.FirewallD1.Exception: COMMAND_FAILED"}
failed: [9.111.250.102] (item=2380) => {"failed": true, "item": 2380, "msg": "ERROR: Exception caught: org.fedoraproject.FirewallD1.Exception: COMMAND_FAILED"}


PLAY RECAP *********************************************************************************************************************************************************************************************************************************
9.111.250.102              : ok=81   changed=16   unreachable=0    failed=1
localhost                  : ok=29   changed=0    unreachable=0    failed=0

Resolving the problem

Restart the firewall daemon service by running the following command:
```
service firewalld restart
```
(OR)
```
systemctl restart firewalld.service
```
Retry the installation.