Exercise: Implementing a playbook

Implementing an Ansible Playbook

• Write and run a playbook that installs, configures and verifies web and database services on a managed host.

Prerequisites: Complete control-node setup and the preceding lessons in this chapter. Run commands as student on workstation unless a step names another machine.

From the project directory, run the relevant home-lab check. For an exercise with several checkpoints, grade each state before changing or removing it:

lab grade playbook-review

The grader reads project files and host state. A passing report covers the listed checks; also perform the task’s independent connection, repeat-run, and reboot checks where requested.

Remove the PHP page in the disposable lab. Explain whether the verification catches that fault, then repair it.

Record the published result first. The grader checks the original requirements, so a changed name or value may intentionally fail those checks.

Prepare serverb to serve the provided PHP page, using internet.yml.

• Install current firewalld, httpd, mariadb-server, php, and php-mysqlnd packages. The firewall, Apache, and MariaDB must run and start at boot.
• HTTP must be allowed persistently. The supplied index.php must be under /var/www/html/ with mode 0644.
• An unprivileged verification play on workstation must require HTTP 200 from serverb. Repeat the deployment and investigate unexpected changes.

Start a play for serverb

In ~/playbook-review, create internet.yml. Add a play named Enable internet services for serverb.lab.example.com, with privilege escalation enabled and a task list.

---
- name: Enable internet services
  hosts: serverb.lab.example.com
  become: true
  tasks:

Install the packages

Add one task that installs the latest versions of firewalld, httpd, mariadb-server, php and php-mysqlnd.

    - name: Latest version of all required packages installed
      ansible.builtin.dnf:
        name:
          - firewalld
          - httpd
          - mariadb-server
          - php
          - php-mysqlnd
        state: latest

Configure the firewall

Make sure firewalld is enabled and running, and that the http service is allowed, permanently and immediately.

    - name: firewalld enabled and running
      ansible.builtin.service:
        name: firewalld
        enabled: true
        state: started

    - name: firewalld permits http service
      ansible.posix.firewalld:
        service: http
        permanent: true
        state: enabled
        immediate: true

Start the services

Make sure httpd and mariadb are both enabled and running.

    - name: httpd enabled and running
      ansible.builtin.service:
        name: httpd
        enabled: true
        state: started

    - name: mariadb enabled and running
      ansible.builtin.service:
        name: mariadb
        enabled: true
        state: started

Deploy the PHP page

Copy ~/playbook-review/index.php to /var/www/html/ on the managed host, with file mode 0644.

    - name: Test php page is installed
      ansible.builtin.copy:
        src: index.php
        dest: /var/www/html/index.php
        mode: 0644

Relative src paths are looked up next to the playbook (and in a files/ directory beside it).

Add a test play

Add a second play named Test internet web server that runs on the workstation host without privilege escalation, and uses ansible.builtin.uri to request http://serverb.lab.example.com, expecting status code 200.

- name: Test internet web server
  hosts: workstation
  become: false
  tasks:
    - name: Connect to internet web server
      ansible.builtin.uri:
        url: http://serverb.lab.example.com
        status_code: 200

Validate and run

Syntax-check the playbook, then run it and read the output.

[student@workstation playbook-review]$ ansible-navigator run \
> -m stdout internet.yml --syntax-check
playbook: /home/student/playbook-review/internet.yml
[student@workstation playbook-review]$ ansible-navigator run -m stdout internet.yml
...output omitted...
PLAY RECAP *********************************************************************
serverb.lab.example.com    : ok=7    changed=5    unreachable=0    failed=0  ...
workstation                : ok=2    changed=0    unreachable=0    failed=0  ...

Why changed=5 and not 6? In the classroom firewalld is already running on serverb, so that task reports ok.

Grade and finish

Check your work with lab grade playbook-review, then put the exercise away with lab finish playbook-review.