Demo

The Linux System Roles are a collection of roles and modules executed by Ansible to assist Linux admins in the configuration of common GNU/Linux subsystems. Conceptually, the intent is to serve as a consistent “API” to a give Linux distribution that is consistent across multiple major and minor releases. This collection is available in Ansible Galaxy at linux-system-roles.

Demo time!

This demo provides a collection of ansible playbooks that call upon the Linux System Roles to configure aspects of a test subject virtual machine.

This demo assumes the follow environment is already configured:

Control Node

• RHEL 7.4 or later, physical or virtual
• Subscribed to Red Hat Subscription Manager (RHSM)
• Base and Extras channels enabled
• Name resolution of test environment. Could be /etc/hosts
• Ansible inventory populated
• Root ssh keys have been exchanged to grant access; use ssh-copy-id

[root@rhel74-controlnode ~]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

192.168.75.224 rhel74-controlNode
192.168.75.200 rhel74-test

[root@rhel74-controlnode ~]# head /etc/ansible/hosts
localhost
rhel74-controlNode

[rhel:children]
rhel7_hosts
rhel6_hosts

[rhel7_hosts]
rhel74-controlNode
rhel74-test

[root@rhel74-controlnode ~]# ssh-copy-id root@rhel74-test

Test subject virtual machine

• Virtual machine (easiest way to test multiple NICs and kdump)
  • vCPU, 2G RAM
  • RHEL 6.9 or later
• Subscribed to Red Hat Subscription Manager (RHSM)
• Base and Extras channels enabled

Running the demo

Execute the Ansible commands on the ControlNode and the verification commands on the managed client node.

ansible rhel74-test -m setup -a 'gather_subset=network'
ansible rhel74-test -m setup -a 'gather_subset=network filter=ansible_interfaces'
ansible rhel74-test -m setup -a 'gather_subset=network filter=ansible_e*' |grep -e ansible_e -e macaddr

ansible-playbook -l rhel74-test 1example-network.yml
    # verify on test node
    nmcli c;  nmcli d;
    ip addr

ansible-playbook -l rhel74-test 2example-network-remove.yml
    # verify on test node
    nmcli c;  nmcli d;
    ip addr

ansible-playbook -l rhel74-test 3example-timesync.yml
    # verify on test node
    systemctl list-units | grep -i -e ntp -e chrony
    systemctl status chronyd.service
    ls /etc/chrony*
    less /etc/chrony.conf

ansible-playbook -l rhel74-test 4example-first-kdump.yml
ansible-playbook -l rhel74-test 5example-selinux.yml
# These two steps will do the very basics to enable kdump and selinux.
# However, if not previously configured during install time, they will
# require a reboot.  This is not automatically done by Ansible or the
# System Roles by design.

ansible-playbook -l rhel74-test 6example-kdump.yml
    # verify on test node
    getenforce
    ls -lZd /var/mycrash
    systemctl status kdump
    ls /etc/kdump*
    less /etc/kdump.conf