troubleshooting

Here are the top troubleshooting and challenge-based questions specifically for Ansible, covering real-world issues you might face in your Infosys DevOps Consultant interview.

---

🔹 Ansible Troubleshooting Questions & Answers

1️⃣ Q: Ansible Target Unreachable ("UNREACHABLE! => Failed to connect to the host")

💡 Scenario: Your Ansible playbook fails with an unreachable error.

✅ Answer:

1. Check if the target server is reachable:

   ping -c 3 <target-server>

   • If the ping fails, the target machine is down or unreachable.

2. Verify SSH access from the Ansible server:

   ssh user@target-server

   • If it fails, check if SSH service is running:

     systemctl status sshd

3. Ensure port 22 is open on the target:

   nc -zv <target-server> 22

   • If this fails, allow SSH in the firewall:

     sudo ufw allow 22/tcp

4. Check inventory file and ensure the correct SSH user and key are specified:

   [web_servers]
   192.168.1.10 ansible_user=ubuntu ansible_ssh_private_key_file=~/.ssh/ansible_id_rsa

---

2️⃣ Q: Ansible SSH Authentication Fails ("Permission Denied (publickey)")

💡 Scenario: Ansible fails to connect due to an SSH authentication error.

✅ Answer:

1. Ensure Ansible's public key is added to the target server:

   ssh-copy-id -i ~/.ssh/ansible_id_rsa.pub user@target-server

2. Verify that SSH key authentication is enabled in /etc/ssh/sshd_config:

   grep "PubkeyAuthentication" /etc/ssh/sshd_config

   • If disabled, enable it:

     echo "PubkeyAuthentication yes" >> /etc/ssh/sshd_config
     sudo systemctl restart sshd

3. Check if the private key is correctly set in Ansible inventory:

   ansible_ssh_private_key_file=~/.ssh/ansible_id_rsa

---

3️⃣ Q: Ansible Playbook Fails Due to Sudo Permission Issues ("BECOME FAILED!")

💡 Scenario: Tasks that require sudo fail with a "Permission denied" error.

✅ Answer:

1. Ensure the user is in the sudoers list:

   sudo usermod -aG sudo ansible_user

2. If the user requires a password for sudo, set become_ask_pass=true:

   ansible-playbook playbook.yml --ask-become-pass

3. If using passwordless sudo, ensure the following is added to /etc/sudoers:

   ansible_user ALL=(ALL) NOPASSWD: ALL

---

4️⃣ Q: Ansible Playbook Fails with "Undefined Variable" Error

💡 Scenario: The playbook fails due to an undefined variable.

✅ Answer:

1. Check if the variable is missing in the playbook:

   - hosts: web_servers
     vars:
       my_var: "Hello"
     tasks:
       - debug:
           msg: "{{ my_var }}"

2. Use set_fact to define variables dynamically:

   - name: Define my_var
     set_fact:
       my_var: "Hello from set_fact"

3. Use default filter to handle missing variables:

   - debug:
       msg: "{{ my_var | default('Default Value') }}"

---

5️⃣ Q: Ansible Playbook Runs Slowly. How to Speed It Up?

💡 Scenario: Ansible tasks are taking too long to execute.

✅ Answer:

1. Enable SSH Multiplexing in ansible.cfg:

   [ssh_connection]
   ssh_args = -o ControlMaster=auto -o ControlPersist=60s

2. Use parallel execution by increasing forks:

   ansible-playbook -f 10 playbook.yml

   • Default forks value is 5, increasing it speeds up execution.

3. Use async to run tasks in parallel:

   - name: Install multiple packages
     apt:
       name: nginx
       state: present
     async: 45
     poll: 0

---

6️⃣ Q: Ansible Playbook Fails Due to Package Manager Lock (APT/YUM Lock Issue)

💡 Scenario: Package installation fails due to another process holding the package manager lock.

✅ Answer:

1. For Ubuntu/Debian (APT Lock Issue):

   sudo rm /var/lib/dpkg/lock
   sudo dpkg --configure -a

2. For RHEL/CentOS (YUM Lock Issue):

   sudo rm -rf /var/run/yum.pid

3. Modify the Ansible task to retry if locked:

   - name: Install nginx
     apt:
       name: nginx
       state: present
     register: result
     until: result is succeeded
     retries: 5
     delay: 10

---

7️⃣ Q: How to Debug Ansible Playbook Failures?

💡 Scenario: Your playbook fails, but the error message isn’t clear.

✅ Answer:

1. Run playbook in verbose mode for detailed logs:

   ansible-playbook playbook.yml -vvv

2. Use the debug module to print variable values:

   - debug:
       var: ansible_facts

3. Enable logging in ansible.cfg:

   [defaults]
   log_path = /var/log/ansible.log

---

8️⃣ Q: Ansible Playbook Works on Some Hosts but Fails on Others

💡 Scenario: A playbook runs fine on some servers but fails on others.

✅ Answer:

1. Run a connectivity check:

   ansible all -m ping

2. Check OS differences:

   ansible all -m setup | grep ansible_os_family

   • If OS versions differ, adjust the playbook:

     - name: Install package
       package:
         name: "{{ 'nginx' if ansible_os_family == 'Debian' else 'httpd' }}"

---

9️⃣ Q: How to Prevent Ansible from Changing a Configured File if There Are No Updates?

💡 Scenario: You only want Ansible to update a file if its content changes.

✅ Answer: Use the checksum feature:

- name: Copy configuration file only if changed
  copy:
    src: myconfig.conf
    dest: /etc/myconfig.conf
    owner: root
    group: root
    mode: '0644'
  notify: restart_service

• This prevents unnecessary restarts if the file hasn’t changed.

---

🔹 Final Tips to Crack Your Infosys Interview

✅ Explain problems using a structured approach:

• What is the issue?

• How do you diagnose it?

• What is the best fix?

• How do you prevent it in the future?

✅ Be ready for scenario-based questions. ✅ Demonstrate troubleshooting skills with hands-on solutions.

Do you want mock interview questions or more in-depth scenarios? 🔥