⭐ RHCE

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Description:

These are a few practice exams to get ready for the Red Hat Certified Engineer exam
The first practice exam was created by Lisenet . The practice exams cover as many of the exam objectives as possible

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Contents

• RHCE8 Practice Exam 1
• RHCE8 Practice Exam 2

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Requirements :

• You will need five RHEL 8 virtual machines to be able to successfully complete all questions.
• One VM will be configured as an Ansible control node.
• Other four VMs will be used to apply playbooks to solve the sample exam questions.

RHCE8 Practice Exam 1

• Task 1 :
  Install ansible package on the control node (including any dependencies) and configure the following:
  
  • 1 - Create a regular user automation with the password of devops. Use this user for all sample exam tasks.
  • 2 - All playbooks and other Ansible configuration that you create for this sample exam should be stored in /home/automation/plays.
    
  • 3 - Create a configuration file /home/automation/plays/ansible.cfg to meet the following requirements:
    • The roles path should include /home/automation/plays/roles, as well as any other path that may be required for the course of the sample exam.
    • The inventory file path is /home/automation/plays/inventory.
    • Privilege escallation is disabled by default.
    • Ansible should be able to manage 10 hosts at a single time.
    • Ansible should connect to all managed nodes using the automation user.
    • Create an inventory file /home/automation/plays/inventory with the following:
      • ansible2.hl.local is a member of the proxy host group.
      • ansible3.hl.local is a member of the webservers host group.
      • ansible4.hl.local is a member of the webservers host group.
      • ansible5.hl.local is a member of the database host group
        

Solution of Task1

• Task 2 :
  

  • Generate an SSH key pair on the control node for the automation user. You can perform this step manually.
  • Write a script /home/automation/plays/adhoc.sh that uses Ansible ad-hoc commands to achieve the following:
    • User automation is created on all inventory hosts.
    • The SSH public key that you just generated is copied to all managed hosts for the automation user.
    • The automation user has full sudo access on all managed nodes without having to provide a password.

  After running the adhoc.sh bash script, you should be able to SSH into all managed hosts using the automation user without a password, as well as a run all privileged commands.

Solution of Task2

• Task 3 :
  

• Create a playbook /home/automation/plays/motd.yml that runs on all inventory hosts and does the following:
  The playbook should replace any existing content of /etc/motd with text. Text depends on the host group.

  • On hosts in the proxy host group the line should be “Welcome to HAProxy server”.
  • On hosts in the webserver host group the line should be “Welcome to Apache server”.
  • On hosts in the database host group the line should be “Welcome to MySQL server”

Solution of Task3

• Task 4 :
  

  Create a playbook /home/automation/plays/sshd.yml that runs on all inventory hosts and configures SSHD daemon as follows:

  1. banner is set to /etc/motd
  2. X11Forwarding is disabled
  3. MaxAuthTries is set to 3

Solution of Task4

• Task 5 :
  Create Ansible vault file /home/automation/plays/secret.yml. Encryption/decryption password is devops.
  Add the following variables to the vault:
  1. user_password with value of devops
  2. database_password with value of devops

Solution of Task5

• Task 6 :
  You have been provided with the list of users below. Use /home/automation/plays/vars/user_list.yml file to save this content.

---
users:
- username: aliceuid: 1201
- username: vincentuid: 1202
- username: sandyuid: 2201
- username: patrickuid: 2202

• Create a playbook /home/automation/plays/users.yml that uses the vault file /home/automation/plays/secret.yml to achieve the following:
  1. Users whose user ID starts with 1 should be created on servers in the webservers host group.
  2. Users whose user ID starts with 2 should be created on servers in the database host group.
  3. All users should be members of a supplementary group wheel. All users password should be used from the user_password variable
  4. Shell should be set to /bin/bash for all users.
  5. Account passwords should use the SHA512 hash format.
     After running the playbook, users should be able to SSH into their respective servers without passwords.

Solution of Task6

• Task 7 :
  
• Create a playbook /home/automation/plays/regular_tasks.yml that runs on servers in the proxy host group and does the following:
  1. A root crontab record is created that runs every hour.
  2. The cron job appends the file /var/log/time.log with the output from the date command.

Solution of Task7

• Task 8 :
  Create a playbook /home/automation/plays/repository.yml that runs on servers in the database host group and does the following:

  1. A YUM repository file is created.
  2. The name of the repository is mysql56-community.
  3. The description of the repository is “MySQL 5.6 YUM Repo”.
  4. Repository baseurl is http://repo.mysql.com/yum/mysql-5.6-community/el/7/x86_64/.
  5. Repository GPG key is at http://repo.mysql.com/RPM-GPG-KEY-mysql.
  6. Repository GPG check is enabled.
  7. Repository is enabled.

  Solution of Task8

• Task 9 :
  Create a role called sample-mysql and store it in /home/automation/plays/roles. The role should satisfy the following requirements:

1. A primary partition number 1 of size 800MB on device /dev/sdb is created.
2. An LVM volume group called vg_database is created that uses the primary partition created above.
3. An LVM logical volume called lv_mysql is created of size 512MB in the volume group vg_database.
4. An XFS filesystem on the logical volume lv_mysql is created.
5. Logical volume lv_mysql is permanently mounted on /mnt/mysql_backups.
6. mysql-community-server package is installed.
7. Firewall is configured to allow all incoming traffic on MySQL port TCP 3306.
8. MySQL root user password should be set from the variable database_password (see task #5).
9. MySQL server should be started and enabled on boot. 10.MySQL server configuration file is generated from the my.cnf.j2 Jinja2 template with the following content:

[mysqld]
bind_address = {{ ansible_default_ipv4.address }}
skip_name_resolve
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
symbolic-links=0
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

Create a playbook /home/automation/plays/mysql.yml that uses the role and runs on hosts in the database host group. Solution of Task9

• Task 10 :
  Use Ansible Galaxy to download and install geerlingguy.haproxy role in /home/automation/plays/roles. Create a playbook /home/automation/plays/haproxy.yml that runs on servers in the proxy host group and does the following:
  1. Use geerlingguy.haproxy role to load balance request between hosts in the webservers host group.
  2. Use roundrobin load balancing method.
  3. HAProxy backend servers should be configured for HTTP only (port 80).
  4. Firewall is configured to allow all incoming traffic on port TCP 80. If your playbook works, then doing “curl http://ansible2.hl.local/” should return output from the web server (see task #9 ). Running the command again should return output from the other web server.

Solution of Task10

• Task 11 :
  Create a playbook /home/automation/plays/selinux.yml that runs on hosts in the webservers host group and does the following:
  1. Uses the selinux RHEL system role.
  2. Enables httpd_can_network_connect SELinux boolean.
  3. The change must survive system reboot

Solution of Task11

• Task 12 :
  Create a playbook /home/automation/plays/sysctl.yml that runs on all inventory hosts and does the following:
  1. If a server has more than 2048MB of RAM, then parameter vm.swappiness is set to 10.
  2. If a server has less than 2048MB of RAM, then the following error message is displayed: Server memory less than 2048MB

Solution of Task12

• Task 13 :
  Create a playbook /home/automation/plays/archive.yml that runs on hosts in the database host group and does the following:
  1. A file /mnt/mysql_backups/database_list.txt is created that contains the following line: dev,test,qa,prod.
  2. A gzip archive of the file /mnt/mysql_backups/database_list.txt is created and stored in /mnt/mysql_backups/archive.gz

Solution of Task13

• Task 14 :
  

  Create a playbook /home/automation/plays/packages.yml that runs on all inventory hosts and does the following:

  1. Installs tcpdump and mailx packages on hosts in the proxy host groups.
  2. Installs lsof and mailx and packages on hosts in the database host groups.

Solution of Task14

• Task 15 :
  Create a playbook /home/automation/plays/target.yml that runs on hosts in the webserver host group and does the following:
  1. Sets the default boot target to multi-user.

Solution of Task15

• Task 16 :
  Create a playbook /home/automation/plays/server_list.yml that does the following:
  1. Playbook uses a Jinja2 template server_list.j2 to create a file /etc/server_list.txt on hosts in the database host group.
  2. The file /etc/server_list.txt is owned by the automation user.
  3. File permissions are set to 0600.
  4. SELinux file label should be set to net_conf_t.
  5. The content of the file is a list of FQDNs of all inventory hosts. After running the playbook, the content of the file /etc/server_list.txt should be the following: ansible2.hl.local ansible3.hl.local ansible4.hl.local ansible5.hl.local Note: if the FQDN of any inventory host changes, re-running the playbook should update the file with the new values.

Solution of Task16

Solution of Task1

Ansible-installation : # yum list installed platform-python # yum install ansible # ansible --version 1- # useradd automation # echo "devops" | passwd --stdin automation 2- # su - automation # mkdir plays ; cd plays 3- # vim ansible.cfg ## Ansible.config file [defaults]role_path = ./rolesinventory = ./inventoryforks = 10remote_user = automation [privilege_escalation]become = False# vim inventory [proxy]ansible2.hl.local [webservers]ansible3.hl.local ansible4.hl.local [database]ansible5.hl.local # ansible all --list-hosts

Solution of Task2

# echo "automation ALL=(ALL) NOPASSWD:ALL" > /etc/sudoers.d/automation# ssh-keygen # vim adhoc.sh #!/bin/bash# you can specify the inventory file with -i option 
ansible all -m user -a "user='automation'\ comment='User Create by Ansible'" -u root --ask-pass ansible all -m authorized_key -a "user=automation state=present \ key={{ lookup('file', '/home/automation/.ssh/id_rsa.pub') }}" -u root --ask-pass
ansible all -m copy -a "src='/etc/sudoers.d/automation' dest='/etc/sudoers.d/'" -u root --ask-pass
# chmod 755 adhoc.sh # ./adhoc.sh

Solution of Task3

# mkdir group_vars ; cd group_vars# echo "message: Welcome to HAProxy server" >> proxy# echo "message: Welcome to Apache server" >> webserver# echo "message: Welcome to MySQLserver" >> database

--- - name: Customize the message of the dayhosts: alltasks:
- name: Create the message of the day according to the managed hostcopy:
content: "{{ message }}"dest: /etc/motd owner: rootgroup: root mode: '0644'
...

Solution of Task4

# vim defaults/main.yml # sshd config variables
ssh_config: - start_line: "^banner"
line: "banner /etc/motd"
- start_line: "X11Forwarding"
line: "X11Forwarding no"
- start_line: "^#MaxAuthTries"
line: "MaxAuthTries yes"

--- - name: Configure the sshd service hosts: all vars_files:
- defaults/main.ymltasks: - name: Adding sshd config lineinfile:
path: /etc/ssh/sshd_config regexp: "{{ item.start_line }}"line: "{{ item.line }}"loop: "{{ ssh_config }}"notify: restart sshd # don't forget to restart the servicehandler:
- name: restart sshd service: name: sshd state: restarted
...
# ansible all -m command -a 'grep "MaxAuthTries" /etc/ssh/sshd_config' 

Solution of Task5

# ansible-vault create secret.yml
New Vault password: devops
Confirm New Vault password: devops
---
user_password: devops
database_password: devops
using the decr with vault-file :# vim vault-key
devops
# chmod 400 vault-key # ansible-vault view secret.yml --vault-password-file vault-key 
---
user_password: devops
database_password: devops

Solution of Task6

---
- name: Create usershosts: allbecome: yesvars_files:
- ./users_list.yml
- ./secret.ymltasks:
- name: Ensure group is existgroup:
name: wheelstate: present
- name: Create users that starts with 1 in their uiduser:
name: "{{ item.username }}"group: wheelpassword: "{{ user_password | password_hash('sha512') }}"shell: /bin/bashupdate_password: on_createwith_items: "{{ users }}"when:
- ansible_fqdn in groups['webservers']
- "item.uid|string|first == '1'"
- name: Create users that starts with 2 in their uiduser:
name: "{{ item.username }}"group: wheelpassword: "{{ user_password | password_hash('sha512') }}"shell: /bin/bashupdate_password: on_createwith_items: "{{ users }}"when:
- ansible_fqdn in groups['database']
- "item.uid|string|first == '2'"

Solution of Task7

---
- name: Scheduled taskshosts: proxybecome: yestasks:
- name: Ensure file existsfile:
path: /var/log/time.logstate: touchmode: 0644
- name: Create cronjob for root usercron:
name: "check time"hour: "*/1"user: rootjob: "date >> /var/log/time.log"

Solution of Task8

---
- name: Software repositorieshosts: databasebecome: yestasks:
- name: Create msyql repositoryyum_repository:
name: mysql56-communitydescription: "MySQL 5.6 YUM Repo"baseurl: "http://repo.mysql.com/yum/mysql-5.6-community/el/7/x86_64/"enabled: yesgpgcheck: yesgpgkey: "http://repo.mysql.com/RPM-GPG-KEY-mysql"# ansible database -m command -a 'cat /etc/yum.repos.d/MariaDB-10.5.repo' -b

Solution of Task9

# cd roles # ansible-galaxy init sample-mysql# cd sample-mysql# vim vars/main.yml
---
partitions: - number: 1start: 1MiBend: 800MiBdevice: /dev/sdbvolume_groups: - name: vg_databasedevice: /dev/sdb1 logical_volumes: - name: lv_mysql size: 512MiBvgroup: vg_databasemount_path: /mnt/mysql_backups mysql_service: mariadbmysql_packages:
- mariadb
- mariadb-server
- python3-PyMySQL
...

# vim tasks/main.yml
---
- name: Create a primary partition on /dev/sdb parted: device: "{{ item.device }}"number: "{{ item.number }}"part_start: "{{ item.start }}"part_end: "{{ item.end }}"part_type: primarystate: presentunit: MiBloop: "{{ partitions }}"
- name: Ensure Volume group exist lvg: vg: "{{ item.name }}"pvs: "{{ item.device }}"loop: "{{ volume_groups }}" - name: Ensure Logical Volume exist lvol: lv: "{{ item.name }}"vg: "{{ item.vgroup }}"size: "{{ item.size }}"state: presentloop: "{{ logical_volumes }}"when: item.name not in ansible_lvm["lvs"]
- name: Create XFS filesystem filesystem: dev: "/dev/{{ item.vgroup }}/{{ item.name }}"type: xfsloop: "{{ logical_volumes }}" - name: Ensure Correct Capacity for {{ lv_name }}lvol:
vg: "{{ item.vgroup }}"lv: "{{ item.name }}"size: "{{ item.size }}"resizefs: trueforce: yesloop: "{{ logical_volumes }}"## remembre that the fs XFS does not support shrinking capacity
- name: Ensure the FS is mounted mount: src: /dev/{{ item.vgroup }}/{{ item.name }}"path: "{{ item.mount_path }}"fstype: xfs state: mountedloop: "{{ logical_volumes }}" - name: Ensure mysql is installedyum:
name: "{{ packages }}"state: present
- name: Ensure MySQL is enabled and startedservice: name: "{{ mysql_service }}"state: startedenabled: true
- name: Enable MySQL in firewalld firewalld: service: "{{ mysql_service }}"state: enabled permanent: trueimmediate: true
- name: Change MySQL root user passwordmysql_user: name: root password: "{{ database_password }}"state: present
- name: Copy my.cnf.j2 to /etc/my.cnftemplate:
src: my.cnf.j2dest: /etc/my.cnfnotify: restart mysql 

# vim handlers/main.yml
---
- name: restart mysql service: name: "{{ mysql_srv }}"state: restarted

# vim templates/my.cfg.j2{{ ansible_managed }}[mysqld]bind_address = {{ ansible_facts['default_ipv4']['address'] }}skip_name_resolvedatadir = /var/lib/mysqlsocket = /var/lib/mysql/mysql.socksymbolic-links = 0sql_mode = NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES[mysqld_safe]log-error = /var/log/mysqld.logpid-file = /var/run/mysqld/mysqld.pid

# vim mysql.yml
--- - name: Install mysql role hosts: databsevars_files:
- secret.ymlroles: sample-mysql

Solution of Task10

# ansible-galaxy install geerlingguy.haproxy -p roles/

---
- name: Configure HAPROXYhosts: proxybecome: yesroles:
- geerlingguy.haproxyvars:
haproxy_frontend_port: 80haproxy_frontend_mode: 'http'haproxy_backend_balance_method: 'roundrobin'haproxy_backend_servers:
- name: app1address: 10.0.0.23 # The @ ip of the webservers
- name: app2address: 10.0.0.25tasks:
- name: Ensure firewalld and its dependencies are installedyum:
name: firewalldstate: latest
- name: Ensure firewalld is runningservice:
name: firewalldstate: startedenabled: yes
- name: Ensure firewalld is allowing to the trafficfirewalld:
port: 80/tcppermanent: yesimmediate: yesstate: enabled# ansible proxy -m command -a 'systemctl is-enabled haproxy' -b# curl http://ansible2.hl.local/

Solution of Task11

If you get stuck and forget the syntax, try this command :

# find /usr/share/ -iname example-selinux* 

---
- name: Configure SELinuxhosts: webserversbecome: truetasks:
- name: Configure SELinuxblock:
- include_role:
name: rhel-system-roles.selinuxrescue:
# Fail if failed for a different reason than selinux_reboot_required.
- name: handle errorsfail:
msg: "role failed"when: not selinux_reboot_required
- name: restart managed hostreboot:
msg: "Ansible updates triggered"ignore_errors: true
- name: wait for managed host to come back wait_for_connections: delay: 10timeout: 300
- name: reapply the roleinclude_role:
name: rhel-system-roles.selinux

Solution of Task12

---
- name: Set sysctl Parametershosts: allbecome: truevars: min_ram_mb: 2048tasks:
- name: Print error messagedebug:
msg: "Server memory less than 2048MB"when: ansible_memtotal_mb < min_ram_mb
- name: set vm.swappiness to 10sysctl:
name: vm.swappinessvalue: '10'state: presentwhen: ansible_memtotal_mb > min_ram_mb

Solution of Task13

--
- name: Use Archivinghosts: databasebecome: yestasks:
- name: Create a directory if it does not exist file:
path: /mnt/mysql_backups/state: directorymode: 0775owner: rootgroup: root
- name: Copy the contentcopy:
content: "dev,test,qa,prod"dest: /mnt/mysql_backups/database_list.txt
- name: Create archivearchive:
path: /mnt/mysql_backups/database_list.txtdest: /mnt/mysql_backups/archive.gzformat: gz

--### Solution of Task14

---
- name: Install packageshosts: allbecome: yestasks:
- name: Installs tcpdump and mailx packages on hosts in the proxy host groupsyum:
name:
- tcpdump
- mailxstate: latestwhen: inventory_hostname in groups['proxy']
- name: Installs lsof and mailx and packages on hosts in the database host groupsyum:
name:
- lsof
- mailxstate: latestwhen: inventory_hostname in groups['database']

Solution of Task15

---
- name: default boot targethosts: webserversbecome: yestasks:
- name: Set default boot target to multi-userfile:
src: /usr/lib/systemd/system/multi-user.targetdest: /etc/systemd/system/default.targetstate: link

Solution of Task16

# vim server_list.j2{% for host in groups['all'] %}{{ hostvars[host].inventory_hostname }}{% endfor %}

# vim server_list.yml
---
- name: Create and Use Templates to Create Customised Configuration Fileshosts: databasebecome: yestasks:
- name: Create server listtemplate:
src: ./server_list.j2dest: /etc/server_list.txtowner: cloud_usermode: '0600'setype: net_conf_t

RHCE8 Practice Exam 2

• Will be updated soon