Chapter 3 - Possible Firewall configuration issue

### Host configuration
Command host: RHEL 9..5 (Plow)
Ansible version: 2.14.17

### Section: Configure the Database servers
**The following commands fail:**
```
ansible db -b -m firewalld -a "zone=database state=present permanent=yes"
ansible db -b -m firewalld -a "source=192.168.56.0/24 zone=database state=enabled permanent=yes"
ansible db -b -m firewalld -a "port=3306/tcp zone=database state=enabled permanent=yes"
```

**The error message:**
```
192.168.56.6 | FAILED! => {
"msg": "The module firewalld was redirected to ansible.posix.firewalld, which could not be loaded."
}
```

To make the example code work, the ansible.posix collection is required. The collection is not supported until Ansible 2.15, but the default yum install of ansible-core installs 2.14. Newer versions can be downloaded from the Ansible community site and installed manually.

**Workaround:**
Modify the ansible commands as follows:
```
ansible db -b -a "firewall-cmd --new-zone=database --permanent"
ansible db -b -a "firewall-cmd --add-source=192.168.65.0/24 --zone=database --permanent"
ansible db -b -a "firewall-cmd --add-port=3306/tcp --zone=database --permanent"
ansible db -b -a "firewall-cmd --add-port=22/tcp --zone=database --permanent"
ansible db -b -a "firewall-cmd --set-default-zone=database"
ansible db -b -a "firewall-cmd --reload"
```
Note that port 22 for ssh needs to be opened in the database zone in order for vagrant ssh to be able to reconnect