RHCE | Exam Revision Questions and Answers | All Correct

RHCE | Exam Revision Questions and Answers | All Correct What is Ansible? - Answer️️ -Open source automation platform providing language that allows to describe in a declarative fashion a desired state of IT application infrastructure. Ansible Playbooks are written in... - Answer️️ -YAML Ansible traits - Answer️️ -1. Agentless - target systems do not need any agent software. Ansible most often connects to target systems via SSH/WinRM and injects small programs called "ansible modules" that put the system in the desired state, described in the playbook. 2. Cross-platform 3. Human-readable Ansible Node Types - Answer️️ -1. Control node - Ansible is installed there and it stores playbooks, inventories etc. 2. Managed hosts - Those are listed in inventories. Hosts which control node connects and makes changes to put them in the desired state, defined by a playbook. ©SOPHIABENNET@2024/2025 Tuesday, August 20, 2024 10:21 AM 2 What does it mean that Ansible is indempotent? - Answer️️ -You can safely run a playbook on the same hosts multiple times. When your systems are in the correct state, the playbook makes no changes when you run it. Not every module adheres to that out of the box. How to register new RHEL for subscription? - Answer️️ -Usually two commands are used to do that: 1. subscription-manager register --username=youruser -- password=yourpwd 2. subscription-manager --attach --pool=poolID Where pools and their IDs can be viewed by: subscription-manager list --available How to enable a new RHEL software repository with CMDs? - Answer️️ - To add repo: subscription-manager repos --enable "repo_name" To list repo: ©SOPHIABENNET@2024/2025 Tuesday, August 20, 2024 10:21 AM 3 subscription-manager repos --list What are the requirements for using Ansible on RHEL8? - Answer️️ -1. Python (at least 3.5 or 2.7) - can be "platform-python" pkg 2. "ansible-core" package installed on control node 3. Python in the same minimal version should be present on managed nodes (if SELinux is present, install "python3-libselinux" too) To check: - ansible --version - ansible -m setup localhost | grep python_version What is Ansible Inventory? And what types are there. - Answer️️ - Collection of hosts that Ansible will manage. Those hosts can be assigned to groups that are collectively managed. Those groups can have child groups and hosts can be in multiple groups. Default Ansible inventory resides in /etc/ansible/hosts Inventory can be: 1. Static - defined in a INI or YAML text file ©SOPHIABENNET@2024/2025 Tuesday, August 20, 2024 10:21 AM 4 2. Dynamic - generated by a script or program as needed Groups in Ansible Inventory - Answer️️ -Inventory always has 2 default groups: 1. all - every host mentioned in the inventory 2. ungrouped - every host mentioned in the inventory that is not a member of any other group Normal groups are defined as: [groupname] host1 host2 192.168.0.34 Nested groups are defined as: [biggergroupname:children] groupname Ranges of IP addresses as well as numbers in hostnames are also allowed: [START:END] ©SOPHIABENNET@2024/2025 Tuesday, August 20, 2024 10:21 AM 5 ansible -i groupname --list-hosts - verifies inventory file by listing hosts from a group Ansible configuration files (with precendence) - Answer️️ -From lowest to highest precedence: 1. /etc/ansible/ - default, provided with installation 2. ~/. 3. ./ - directory from which ansible command is executed (most recommended, best practice) 4. ANSIBLE_CONFIG environment variable Ansible looks for those file from 4th to 1st, and uses only configuration from the one it found first. How to generate a sample Ansible config - Answer️️ -ansible-config init -- disabled > Ansible core configuration settings - Answer️️ -[defaults] - default settings for Ansible operation 1. inventory - path to default inventory location 2. remote_user - user to which Ansible should log in on managed hosts 3. ask_pass - if passwordless SSH is not to be preffered ©SOPHIABENNET@2024/2025 Tuesday, August 20, 2024 10:21 AM 6 [privilege_escalation] - configures how Ansible performs privilege escalation on managed hosts 1. become - whether or not to switch a user on managed hosts to root 2. become_method - typically "sudo", can be also "su" 3. become_user - typically and by default root 4. become_ask_pass - whether to prompt for a password when becoming a root Ansible Ad Hoc Command - Answer️️ -A way of executing a single Ansible task quickly, one that you do not need to save to run again later. They are simple, online operations that can be run without writing a playbook. ansible host-pattern -m module [-a 'module arguments'] [-i inventory] How to find Ansible module documentation in command line env? - Answer️️ -Use ansible-doc command: 1. ansible-doc -l - lists all modules 2. ansible-doc <modulename> - show manual about the specific module 3. ansible-doc -s <modulename> - generate a starter template to see how to use a module Most often used Ansible file modules - Answer️️ -1. copy ©SOPHIABENNET@2024/2025 Tuesday, August 20, 2024 10:21 AM 7 2. file 3. lineinfile 4. synchronize Most often used Ansible software package modules - Answer️️ -1. package - universal for most pkg managers 2. yum 3. apt 4. dnf 5. gem 6. pim Most often used Ansible system modules - Answer️️ -1. firewalld 2. reboot 3. service 4. user Most often user Ansible Net-Tools modules - Answer️️ -1. get