5-Day2-2-DebuggingTechniquesAndTroubleshooting

Lab Exercise: for Debugging Techniques and Troubleshooting

Objective: The goal of this exercise is to help participants understand and practice debugging techniques in Ansible using syntax check, check mode, diff mode, and verbose logging. Participants will be provided with intentionally incorrect playbooks to identify and correct errors, as well as examples to understand how each debugging technique works.

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Exercise 1: Syntax Errors

Objective: Identify and fix syntax errors in the provided playbooks.

Instructions:

The following playbooks contain intentional syntax errors. Participants should identify and correct them. Run the playbooks after correcting the errors.

Playbook 1:

- name: Install NGINX on Amazon Linux
  hosts: all
  tasks:
    - name: Install nginx
      yum
        name: nginx
        state: present
    - name: Start nginx service
      services:
        name: nginx
        state: started

Issues to correct:

• Look for any indentation or syntax errors in the playbook that would prevent it from running.

Playbook 2:

- name: Set up firewall rules
  hosts: all
  tasks:
    - name: Allow HTTP traffic
      firewalld:
        service: http
        permanent: true
        state: enabled
    - name: Reload firewall rules
      firewalld:
        state: reloaded
        immediate: yes

Issues to correct:

• Look for missing or incorrect module parameters that may cause syntax issues.

Playbook 3:

- name: Install software and configure a directory
  hosts: all
  tasks:
    - name: Install git
      yum:
        name: git
        state: present

    - name: Create a directory for repositories
        file:
        path: /opt/repositories
        state: directory
        mode: 0755
        owner: root
        group: root

    - name: Clone a repository
      git:
          repo: https://github.com/example/repo.git
        dest: /opt/repositories/myrepo
        version: master

Issues to correct:

• Identify and fix the issues.

Objective for Participants:

• Use ansible-playbook --syntax-check to check for syntax errors.

• Correct the identified errors and re-test the playbook.

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Exercise 2: Check Mode

Objective: Understand the usage of Check Mode by simulating the execution of a playbook without making any actual changes.

Instructions:

The following playbooks will help participants understand how to use check mode. Participants should run these playbooks with the --check option to see the planned changes without actually applying them.

Playbook 1:

- name: Install and Start Apache Server
  hosts: all
  tasks:
    - name: Install Apache
      yum:
        name: httpd
        state: present
    - name: Start Apache service
      service:
        name: httpd
        state: started

Run with:

ansible-playbook playbook.yml --check

Expected Outcome:

• The output will show which tasks will be executed but without actually installing or starting Apache.

Playbook 2:

- name: Create Directory and Copy File
  hosts: all
  tasks:
    - name: Create a directory
      file:
        path: /tmp/example_dir
        state: directory
    - name: Copy a file
      copy:
        src: /path/to/file.txt
        dest: /tmp/example_dir/file.txt

Run with:

ansible-playbook playbook.yml --check

Expected Outcome:

• The output will display the tasks that would be performed (creating the directory and copying the file) but won’t actually modify the system.

Objective for Participants:

• Use the --check option to simulate running a playbook without applying any changes.

• Understand the impact of tasks before executing them.

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Exercise 3: Diff Mode

Objective: Understand how to view file changes using diff mode in Ansible.

Instructions:

Participants will modify a playbook to include file changes and will observe the differences when running the playbook with --diff.

Playbook 1:

- name: Configure nginx index.html
  hosts: all
  tasks:
    - name: Add content to the index.html file
      lineinfile:
        path: /var/www/html/index.html
        line: "Welcome to the Apache Web Server!"
    - name: Add another line to index.html
      lineinfile:
        path: /var/www/html/index.html
        line: "This is the second line added."

Run with:

ansible-playbook playbook.yml --diff

Expected Outcome:

• The output will display the changes made to the index.html file, showing the differences (+ or - symbols) in the file contents.

Playbook 2:

- name: Modify configuration file
  hosts: all
  tasks:
    - name: Modify nginx.conf file
      lineinfile:
        path: /etc/nginx/nginx.conf
        regexp: '^#user'
        line: 'user nginx;'

Run with:

ansible-playbook playbook.yml --diff

Expected Outcome:

• The output will show the change made to the nginx.conf file with diff highlighting, where it will show which lines were modified.

Objective for Participants:

• Use the --diff option to visualize changes in files managed by Ansible.

• Understand how to identify file modifications using the diff output.

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Exercise 4: Verbose Logging

Objective: Understand how to use verbose logging to troubleshoot issues and get detailed information on playbook execution.

Instructions:

Participants will run a playbook with verbose logging enabled using the -vvv option.

Playbook 1:

- name: Install and configure nginx
  hosts: all
  tasks:
    - name: Install nginx
      yum:
        name: nginx
        state: present
    - name: Start nginx service
      service:
        name: nginx
        state: started
    - name: Create index.html
      copy:
        content: "Welcome to Nginx!"
        dest: /usr/share/nginx/html/index.html

Run with:

ansible-playbook playbook.yml -vvv

Expected Outcome:

• The verbose output will show detailed logs of each task's execution, including task start, success/failure messages, and more detailed information about each action.

Playbook 2:

- name: Add a new user and group
  hosts: all
  tasks:
    - name: Create a new user
      user:
        name: exampleuser
        state: present
    - name: Add user to a group
      user:
        name: exampleuser
        groups: sudo
        append: true

Run with:

ansible-playbook playbook.yml -vvv

Expected Outcome:

• The detailed verbose output will show each task’s execution details, including variable values and task results.

Objective for Participants:

• Use the -vvv option to enable verbose logging.

• Understand how verbose output helps troubleshoot issues by providing more information about task execution.

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Conclusion:

By completing these exercises, participants will gain hands-on experience with syntax checks, check mode, diff mode, and verbose logging in Ansible. These techniques will help them troubleshoot playbooks efficiently and understand the impact of their changes before executing them on real systems.