RHCE Study Guide Summary¶

🎯 Concise Reference for RHCE EX294 Exam Success¶

Purpose: Focused summary of essential RHCE exam content covering all objectives without unnecessary detail.

Source Materials:

Sander van Vugt's RHCE Guide (16 chapters) - Primary exam guide
Jeff Geerling's Ansible for DevOps (15 chapters) - Real-world patterns
Red Hat RHCE Study Guide - Exam-focused content

Study Approach: Master these topics through hands-on practice and systematic review.

📋 RHCE Exam Overview¶

Exam Code: EX294 | Duration: 4 hours | Format: Performance-based | Passing Score: 210/300

Prerequisites¶

Current RHCSA certification required
RHEL 8/9 system administration knowledge
Basic Linux command line proficiency

Exam Environment¶

Control Node: RHEL 8/9 with Ansible pre-installed
Managed Nodes: 2-4 RHEL systems for automation targets
Tools Available: ansible-navigator, ansible-doc, man pages (offline only)
No Internet Access: All documentation must be local

🔧 Core RHCE Topics¶

1. Installation and Configuration (20%)¶

Control Node Setup¶

Package Installation: dnf install ansible-core ansible-navigator
Configuration File: /etc/ansible/ansible.cfg or ./ansible.cfg
Key Settings: host_key_checking = False, remote_user = ansible, become = True
Directory Structure: playbooks/, roles/, group_vars/, host_vars/

SSH Key Management¶

Generate Keys: ssh-keygen -t rsa -b 4096
Distribute Keys: ssh-copy-id ansible@managed_node
Test Connectivity: ansible all -m ping

Essential Configuration¶

[defaults]
inventory = inventory.ini
remote_user = ansible
host_key_checking = False
become = True
become_method = sudo
roles_path = ./roles
collections_paths = ./collections

2. Inventory Management (15%)¶

Static Inventory Formats¶

INI Format: Groups in [brackets], hosts listed below
YAML Format: Hierarchical structure with children: and hosts:
Variables: host_vars/ directory or inline hostname var=value

Host Patterns¶

All hosts: all or *
Groups: webservers, databases
Exclusions: webservers:!web03
Intersections: webservers:&production
Regular expressions: ~web\d+

Group Variables¶

Structure: group_vars/groupname.yml or group_vars/groupname/
Precedence: host_vars > group_vars > all
Best Practice: Use descriptive variable names

3. Ad-hoc Commands (10%)¶

Command Structure¶

ansible <pattern> -m <module> -a "<arguments>" [options]

Essential Modules¶

Module	Purpose	Example
`ping`	Connectivity test	`ansible all -m ping`
`command`	Run commands	`ansible all -m command -a "uptime"`
`shell`	Shell with pipes	`ansible all -m shell -a "ps aux \\| grep http"`
`copy`	Copy files	`ansible all -m copy -a "src=file dest=/tmp/"`
`dnf`	Package management	`ansible all -m dnf -a "name=httpd state=present" --become`
`systemd`	Service control	`ansible all -m systemd -a "name=httpd state=started enabled=yes" --become`

Common Options¶

--become or -b: Privilege escalation
--check or -C: Dry run mode
--limit: Target specific hosts
-v/-vv/-vvv: Increase verbosity

4. Playbook Development (25%)¶

Basic Structure¶

---
- name: Playbook description
  hosts: target_group
  become: yes
  vars:
    variable_name: value
  tasks:
    - name: Task description
      module_name:
        parameter: value
      notify: handler_name
  handlers:
    - name: handler_name
      module_name:
        parameter: value

Essential Modules with FQCN¶

Module	FQCN	Primary Use
`dnf`	`ansible.builtin.dnf`	Package management
`systemd`	`ansible.builtin.systemd`	Service control
`copy`	`ansible.builtin.copy`	File copying
`template`	`ansible.builtin.template`	Jinja2 templating
`file`	`ansible.builtin.file`	File/directory operations
`user`	`ansible.builtin.user`	User management
`group`	`ansible.builtin.group`	Group management
`firewalld`	`ansible.posix.firewalld`	Firewall configuration
`mount`	`ansible.posix.mount`	Filesystem mounting
`seboolean`	`ansible.posix.seboolean`	SELinux booleans

Task Control¶

Conditionals: when: condition
Loops: loop: or with_items:
Error Handling: failed_when:, ignore_errors:
Change Control: changed_when:

5. Variables and Facts (20%)¶

Variable Types¶

Type	Scope	Definition Location
Global	All hosts	Command line `-e`
Play	Single play	`vars:` section
Host	Single host	`host_vars/`
Group	Host group	`group_vars/`
Role	Role scope	`roles/*/vars/`
Default	Fallback	`roles/*/defaults/`

Magic Variables¶

inventory_hostname: Current host name
hostvars: All host variables
groups: All inventory groups
group_names: Groups current host belongs to
play_hosts: Hosts in current play

Facts¶

Gathering: Automatic via setup module
Usage: {{ ansible_facts['distribution'] }}
Custom Facts: /etc/ansible/facts.d/*.fact
Disable: gather_facts: no

6. Templates and Jinja2 (15%)¶

Template Basics¶

File Extension: .j2
Module: ansible.builtin.template
Variables: {{ variable_name }}
Conditionals: {% if condition %} ... {% endif %}
Loops: {% for item in list %} ... {% endfor %}

Common Filters¶

Filter	Purpose	Example
`default`	Fallback value	`{{ var \\| default('none') }}`
`upper`/`lower`	Case conversion	`{{ name \\| upper }}`
`length`	Count items	`{{ list \\| length }}`
`join`	Combine with separator	`{{ items \\| join(',') }}`
`regex_replace`	Pattern replacement	`{{ text \\| regex_replace('old', 'new') }}`

Template Example¶

# Generated by Ansible
ServerName {{ ansible_fqdn }}
Listen {{ http_port | default(80) }}

{% for vhost in virtual_hosts %}
<VirtualHost *:{{ http_port }}>
    ServerName {{ vhost.name }}
    DocumentRoot {{ vhost.docroot }}
</VirtualHost>
{% endfor %}

7. Roles and Collections (20%)¶

Role Structure¶

roles/rolename/
├── defaults/main.yml    # Default variables
├── files/              # Static files
├── handlers/main.yml   # Event handlers
├── meta/main.yml       # Role metadata
├── tasks/main.yml      # Primary tasks
├── templates/          # Jinja2 templates
└── vars/main.yml       # Role variables

Role Usage¶

Create: ansible-galaxy init rolename
Install: ansible-galaxy role install author.rolename
Use in Playbook: roles: section or include_role task

Collections¶

Install: ansible-galaxy collection install namespace.collection
Requirements: requirements.yml file
Usage: FQCN format (namespace.collection.module)

Essential Collections¶

Collection	Modules	Use Case
`ansible.builtin`	Core modules	System administration
`ansible.posix`	POSIX tools	Unix/Linux systems
`community.general`	Extended modules	Additional functionality

8. Ansible Vault (15%)¶

Basic Operations¶

Command	Purpose	Usage
`create`	New encrypted file	`ansible-vault create secrets.yml`
`edit`	Modify encrypted file	`ansible-vault edit secrets.yml`
`view`	Read encrypted file	`ansible-vault view secrets.yml`
`encrypt`	Encrypt existing file	`ansible-vault encrypt file.yml`
`decrypt`	Remove encryption	`ansible-vault decrypt file.yml`
`rekey`	Change password	`ansible-vault rekey secrets.yml`

String Encryption¶

Encrypt: ansible-vault encrypt_string 'secret' --name 'db_password'
Usage: Embed in regular YAML files

Playbook Integration¶

Prompt: ansible-navigator run site.yml --ask-vault-pass
File: ansible-navigator run site.yml --vault-password-file .vault_pass
Multiple: ansible-navigator run site.yml --vault-id prod@prompt

9. System Administration Tasks (25%)¶

Package Management¶

- name: Install packages
  ansible.builtin.dnf:
    name: ['httpd', 'php', 'mariadb-server']
    state: present

- name: Update all packages
  ansible.builtin.dnf:
    name: '*'
    state: latest

Service Management¶

- name: Start and enable services
  ansible.builtin.systemd:
    name: "{{ item }}"
    state: started
    enabled: yes
  loop:
    - httpd
    - mariadb

User Management¶

- name: Create user
  ansible.builtin.user:
    name: webuser
    groups: apache
    shell: /bin/bash
    create_home: yes
    state: present

Storage Management¶

- name: Create partition
  community.general.parted:
    device: /dev/sdb
    number: 1
    state: present

- name: Create volume group
  community.general.lvg:
    vg: vg_data
    pvs: /dev/sdb1

- name: Create logical volume
  community.general.lvol:
    vg: vg_data
    lv: lv_web
    size: 2G

Firewall Configuration¶

- name: Configure firewall
  ansible.posix.firewalld:
    service: "{{ item }}"
    permanent: yes
    state: enabled
    immediate: yes
  loop:
    - http
    - https

SELinux Management¶

- name: Set SELinux booleans
  ansible.posix.seboolean:
    name: httpd_can_network_connect
    state: yes
    persistent: yes

10. Automation Content Navigator (10%)¶

Execution Modes¶

Interactive (TUI): ansible-navigator run playbook.yml
Stdout: ansible-navigator run playbook.yml --mode stdout

:help - Show help
:doc module_name - Module documentation
:collections - Browse collections
:inventory - View inventory
:q - Quit

Common Options¶

--check - Dry run mode
--syntax-check - YAML validation
--limit group - Target specific hosts
--tags tag1,tag2 - Run specific tags
--vault-password-file - Vault password

🎯 Exam Strategy and Tips¶

Time Management (4 hours total)¶

Read all tasks first (15 minutes)
Set up environment (30 minutes) - SSH keys, inventory, ansible.cfg
Complete tasks systematically (3 hours)
Verify and test (15 minutes)

Critical Success Factors¶

Test connectivity first: ansible all -m ping
Syntax check always: ansible-navigator run --syntax-check
Use check mode: --check --diff before executing
Know ansible-doc: Your primary reference tool
FQCN required: Always use full module names
Vault everything: Encrypt all sensitive data

Common Pitfalls¶

Wrong tool: Use ansible-navigator not ansible-playbook
Missing FQCN: Short module names will fail
No collections: Install required collections first
SSH issues: Verify key authentication before starting
Syntax errors: One mistake fails entire playbook

Documentation Strategy¶

Module parameters: ansible-doc module_name
Examples: ansible-doc module_name | grep -A20 EXAMPLES
Quick syntax: ansible-doc -s module_name
All modules: ansible-doc -l | grep keyword

Verification Commands¶

# Test playbook execution
ansible-navigator run site.yml --check --diff

# Verify services
ansible all -m systemd -a "name=httpd" --become

# Check files
ansible all -m stat -a "path=/etc/httpd/conf/httpd.conf"

# Test web services
ansible all -m uri -a "url=http://{{ ansible_default_ipv4.address }}"

📚 Essential Module Quick Reference¶

System Management¶

Module	Key Parameters	Example
`ansible.builtin.systemd`	`name`, `state`, `enabled`	`state: started, enabled: yes`
`ansible.builtin.user`	`name`, `groups`, `state`	`name: webuser, groups: apache`
`ansible.builtin.group`	`name`, `state`, `gid`	`name: webgroup, gid: 1001`

Package Management¶

Module	Key Parameters	Example
`ansible.builtin.dnf`	`name`, `state`	`name: httpd, state: present`
`ansible.builtin.package`	`name`, `state`	Generic package module

File Operations¶

Module	Key Parameters	Example
`ansible.builtin.copy`	`src`, `dest`, `owner`, `mode`	`src: file.txt, dest: /tmp/`
`ansible.builtin.template`	`src`, `dest`, `backup`	`src: config.j2, dest: /etc/app/`
`ansible.builtin.file`	`path`, `state`, `owner`, `mode`	`path: /tmp/dir, state: directory`

Network and Security¶

Module	Key Parameters	Example
`ansible.posix.firewalld`	`service`, `port`, `state`	`service: http, state: enabled`
`ansible.posix.seboolean`	`name`, `state`, `persistent`	`name: httpd_can_network_connect`
`ansible.posix.mount`	`path`, `src`, `fstype`, `state`	`path: /mnt, src: /dev/sdb1`

Storage Management¶

Module	Key Parameters	Example
`community.general.parted`	`device`, `number`, `state`	`device: /dev/sdb, number: 1`
`community.general.lvg`	`vg`, `pvs`	`vg: vg_data, pvs: /dev/sdb1`
`community.general.lvol`	`vg`, `lv`, `size`	`vg: vg_data, lv: lv_web, size: 2G`

🏆 Final Preparation Checklist¶

Lab Environment Ready¶

[ ] Control node with Ansible installed
[ ] SSH keys distributed to managed nodes
[ ] Inventory file configured and tested
[ ] Basic playbook execution verified

Core Skills Mastered¶

[ ] Ad-hoc commands for all essential modules
[ ] Playbook structure and syntax
[ ] Variable usage and precedence
[ ] Template creation with Jinja2
[ ] Role development and usage
[ ] Vault encryption for sensitive data

System Administration Tasks¶

[ ] Package installation and updates
[ ] Service start/stop/enable
[ ] User and group management
[ ] File permissions and ownership
[ ] Storage: partitions, LVM, filesystems
[ ] Network: firewall configuration
[ ] Security: SELinux settings

Exam Readiness¶

[ ] ansible-navigator proficiency (TUI and stdout)
[ ] ansible-doc for module reference
[ ] Time management under pressure
[ ] Systematic verification approach
[ ] Troubleshooting failed tasks

Remember: The RHCE exam tests practical automation skills. Focus on hands-on practice over theoretical knowledge.

RHCE Study Guide Summary¶

🎯 Concise Reference for RHCE EX294 Exam Success¶

📋 RHCE Exam Overview¶

Prerequisites¶

Exam Environment¶

🔧 Core RHCE Topics¶

1. Installation and Configuration (20%)¶

Control Node Setup¶

SSH Key Management¶

Essential Configuration¶

2. Inventory Management (15%)¶

Static Inventory Formats¶

Host Patterns¶

Group Variables¶

3. Ad-hoc Commands (10%)¶

Command Structure¶

Essential Modules¶

Common Options¶

4. Playbook Development (25%)¶

Basic Structure¶

Essential Modules with FQCN¶

Task Control¶

5. Variables and Facts (20%)¶

Variable Types¶

Magic Variables¶

Facts¶

6. Templates and Jinja2 (15%)¶

Template Basics¶

Common Filters¶

Template Example¶

7. Roles and Collections (20%)¶

Role Structure¶

Role Usage¶

Collections¶

Essential Collections¶

8. Ansible Vault (15%)¶

Basic Operations¶

String Encryption¶

Playbook Integration¶

9. System Administration Tasks (25%)¶

Package Management¶

Service Management¶

User Management¶

Storage Management¶

Firewall Configuration¶

SELinux Management¶

10. Automation Content Navigator (10%)¶

Execution Modes¶

TUI Navigation¶

Common Options¶

🎯 Exam Strategy and Tips¶

Time Management (4 hours total)¶

Critical Success Factors¶

Common Pitfalls¶

Documentation Strategy¶

Verification Commands¶

📚 Essential Module Quick Reference¶

System Management¶

Package Management¶

File Operations¶

Network and Security¶

Storage Management¶

🏆 Final Preparation Checklist¶

Lab Environment Ready¶

Core Skills Mastered¶

System Administration Tasks¶

Exam Readiness¶