Scenario

🔹 Ansible Scenario-Based Questions & Answers

Here are real-world scenario/requirement-based questions with solutions, answered like a Senior DevOps Engineer. These are the types of questions you can expect in a DevOps Consultant interview at Infosys.

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1️⃣ Q: You need to copy files from one target server to another using Ansible. How will you do it?

💡 Scenario: The application team needs to transfer a configuration file from server1 to server2 using Ansible.

✅ Solution: As a Senior DevOps Engineer, I would use the fetch and copy modules in Ansible to achieve this in a secure and automated way.

Approach:

1. Use fetch to get the file from server1.

2. Use copy to transfer it to server2.

Ansible Playbook:

- name: Copy file from one target to another
  hosts: server1
  tasks:
    - name: Fetch the file from server1
      fetch:
        src: /etc/myapp/config.yaml
        dest: /tmp/config.yaml
        flat: yes  # To avoid creating extra directories

- name: Copy file to server2
  hosts: server2
  tasks:
    - name: Transfer the file to server2
      copy:
        src: /tmp/config.yaml
        dest: /etc/myapp/config.yaml
        owner: root
        group: root
        mode: '0644'

Alternative: Use synchronize (if SSH connectivity exists between servers)

If direct SSH access is available between servers, rsync can be leveraged using Ansible:

- name: Copy file from server1 to server2 using rsync
  hosts: server1
  tasks:
    - name: Synchronize files
      synchronize:
        src: /etc/myapp/config.yaml
        dest: /etc/myapp/config.yaml
        mode: push
        rsync_opts:
          - "--rsh=ssh -i /home/ansible/.ssh/id_rsa"
      delegate_to: server2  # Transfers directly from server1 to server2

---

2️⃣ Q: How do you ensure only one Ansible playbook execution at a time?

💡 Scenario: You have multiple engineers running playbooks, and you want to avoid concurrent execution to prevent race conditions.

✅ Solution: As a Senior DevOps Engineer, I would use file-based locking with the flock command to ensure only one execution at a time.

Approach:

1. Use a lock file to prevent parallel runs.

2. Ensure that if another execution is ongoing, the new one waits.

Ansible Playbook:

- name: Ensure only one playbook execution at a time
  hosts: localhost
  tasks:
    - name: Acquire lock before running playbook
      shell: "flock -n /tmp/ansible.lock -c 'ansible-playbook site.yml'"

• If another playbook is running, it will exit immediately instead of running in parallel.

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3️⃣ Q: How do you run a playbook only if a specific service is running?

💡 Scenario: You need to execute a playbook only if Nginx is running on the target server.

✅ Solution: As a Senior DevOps Engineer, I would use conditionals and service facts to check if the service is active before running the playbook.

Ansible Playbook:

- name: Restart Nginx only if it is running
  hosts: web_servers
  tasks:
    - name: Get service status
      command: systemctl is-active nginx
      register: nginx_status
      ignore_errors: yes

    - name: Restart Nginx if running
      service:
        name: nginx
        state: restarted
      when: nginx_status.stdout == "active"

• If Nginx is running, it restarts.

• If not, it does nothing, avoiding unnecessary actions.

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4️⃣ Q: You need to rollback an Ansible deployment. How would you handle it?

💡 Scenario: A deployment broke production. You need a rollback strategy with Ansible.

✅ Solution: As a Senior DevOps Engineer, I would ensure:

1. Backup current state before deployment.

2. Rollback to the last stable version if an issue occurs.

Ansible Playbook with Rollback Strategy:

- name: Backup and Deploy App
  hosts: app_servers
  tasks:
    - name: Backup existing app
      command: cp -r /var/www/app /var/www/app_backup_{{ ansible_date_time.epoch }}

    - name: Deploy new version
      git:
        repo: "[email protected]:company/app.git"
        dest: "/var/www/app"
        version: "latest"
      register: deploy_result
      ignore_errors: yes

    - name: Rollback if deployment fails
      command: mv /var/www/app_backup_* /var/www/app
      when: deploy_result.failed

• If deployment fails, Ansible automatically rolls back to the last backup.

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5️⃣ Q: How do you manage secrets in Ansible securely?

💡 Scenario: You need to store and use API keys/passwords securely in Ansible playbooks.

✅ Solution: As a Senior DevOps Engineer, I would use Ansible Vault to encrypt sensitive data.

Steps to Secure Secrets:

1. Encrypt a file using Ansible Vault:

   ansible-vault encrypt secrets.yml

2. Use the encrypted file in playbooks:

   - name: Deploy app with secrets
     hosts: app_servers
     vars_files:
       - secrets.yml
     tasks:
       - name: Use API key
         debug:
           msg: "API Key: {{ api_key }}"

3. Decrypt when running the playbook:

   ansible-playbook deploy.yml --ask-vault-pass

• This ensures sensitive data is never stored in plain text.

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6️⃣ Q: How do you ensure idempotency in Ansible playbooks?

💡 Scenario: A junior engineer wrote an Ansible playbook that keeps making changes even when they aren’t needed.

✅ Solution: As a Senior DevOps Engineer, I ensure idempotency using:

• State parameters (state: present)

• changed_when conditions

• Use stat module before making changes

Example: Installing Nginx (Idempotent Approach)

- name: Install Nginx idempotently
  hosts: web_servers
  tasks:
    - name: Check if Nginx is installed
      command: dpkg -l | grep nginx
      register: nginx_installed
      ignore_errors: yes

    - name: Install Nginx only if not installed
      apt:
        name: nginx
        state: present
      when: nginx_installed.rc != 0

• If Nginx is already installed, it does nothing.

• If not installed, it installs it.

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🔹 Key Takeaways to Crack Your Infosys DevOps Consultant Interview

✅ Think like a Senior DevOps Engineer – focus on automation, efficiency, and security. ✅ Use best practices – idempotency, rollback strategies, secure secrets. ✅ Answer with structured solutions – Approach → Playbook → Explanation. ✅ Be ready for scenario-based problem-solving questions.

🔥 Need more scenarios? Let me know, and I'll add them! 🚀

🔹 More Ansible Scenario-Based Interview Questions & Answers (Short & Precise)

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1️⃣ Q: How do you handle dynamic inventories in Ansible?

✅ Use an inventory script or cloud provider plugin like AWS EC2 dynamic inventory:

ansible-inventory -i aws_ec2.yml --list

• Define aws_ec2.yml with the AWS plugin for dynamic inventory fetching.

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2️⃣ Q: How do you run only specific tasks in a playbook?

✅ Use tags and run with --tags or --skip-tags:

tasks:
  - name: Install Nginx
    apt: name=nginx state=present
    tags: install

  - name: Start Nginx
    service: name=nginx state=started
    tags: start

Run only install tasks:

ansible-playbook site.yml --tags install

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3️⃣ Q: How do you execute a playbook in a dry run mode?

✅ Use the --check flag to simulate execution without making changes:

ansible-playbook site.yml --check

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4️⃣ Q: How do you handle errors in Ansible?

✅ Use ignore_errors: yes or failed_when:

- name: Continue even if the command fails
  command: /bin/false
  ignore_errors: yes

✅ Use rescue for rollback:

- block:
    - name: Deploy app
      command: ./deploy.sh
  rescue:
    - name: Rollback if deploy fails
      command: ./rollback.sh

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5️⃣ Q: How do you pass variables to an Ansible playbook?

✅ Pass variables via CLI, inventory, or a file:

ansible-playbook site.yml -e "app_version=2.1"

Inside playbook:

- debug: msg="Deploying version {{ app_version }}"

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6️⃣ Q: How do you run an Ansible task as a different user?

✅ Use become_user:

- name: Run task as postgres user
  become: yes
  become_user: postgres
  command: psql -c "SELECT version();"

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7️⃣ Q: How do you handle dependencies between tasks?

✅ Use when conditions or handlers:

- name: Install Nginx
  apt: name=nginx state=present
  notify: Restart Nginx

handlers:
  - name: Restart Nginx
    service: name=nginx state=restarted

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8️⃣ Q: How do you fetch logs from multiple servers using Ansible?

✅ Use the fetch module:

- name: Get logs from all servers
  fetch:
    src: /var/log/app.log
    dest: ./logs/
    flat: yes

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9️⃣ Q: How do you make Ansible run in parallel across multiple servers?

✅ Use forks in ansible.cfg:

[defaults]
forks = 10

Or set it dynamically:

ansible-playbook site.yml -f 10

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🔟 Q: How do you check if a file exists before performing an action?

✅ Use the stat module:

- name: Check if file exists
  stat:
    path: /etc/myapp/config.yaml
  register: file_stat

- name: Run task if file exists
  debug:
    msg: "File exists!"
  when: file_stat.stat.exists

---

1️⃣1️⃣ Q: How do you limit execution to a single server in an inventory group?

✅ Use --limit flag:

ansible-playbook site.yml --limit "web1"

This runs the playbook only on web1, ignoring other servers.

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1️⃣2️⃣ Q: How do you remove sensitive data from Ansible output?

✅ Use no_log: yes:

- name: Run sensitive command
  shell: echo "Secret Password"
  no_log: yes

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1️⃣3️⃣ Q: How do you troubleshoot when Ansible can't reach a target server?

✅ Check connectivity manually:

ssh user@target -i ~/.ssh/id_rsa

✅ Ensure Ansible can reach the server:

ansible target -m ping -u ansible

✅ Verify SSH access:

• Make sure port 22 is open

• Add Ansible server's public key to target's ~/.ssh/authorized_keys

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1️⃣4️⃣ Q: How do you run an Ansible playbook only on a specific OS?

✅ Use ansible_facts:

- name: Run only on Ubuntu
  debug:
    msg: "This is Ubuntu!"
  when: ansible_facts['os_family'] == "Debian"

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1️⃣5️⃣ Q: How do you ensure a task runs only once in a multi-node setup?

✅ Use run_once:

- name: Run task only once
  debug:
    msg: "This task runs once"
  run_once: yes

---

1️⃣6️⃣ Q: How do you handle large file transfers in Ansible?

✅ Use the synchronize module (rsync-based) for efficiency:

- name: Sync large files
  synchronize:
    src: /data/
    dest: /backup/

---

1️⃣7️⃣ Q: How do you reboot a server and wait for it to come back up?

✅ Use reboot with wait_for_connection:

- name: Reboot and wait
  reboot:
    reboot_timeout: 600  # Wait up to 10 minutes

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1️⃣8️⃣ Q: How do you execute only specific tasks from a playbook?

✅ Use --start-at-task:

ansible-playbook site.yml --start-at-task="Install Nginx"

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1️⃣9️⃣ Q: How do you execute a playbook on a subset of inventory?

✅ Use --limit to restrict execution:

ansible-playbook site.yml --limit "databases"

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2️⃣0️⃣ Q: How do you update all packages on a server using Ansible?

✅ Use package module:

- name: Update all packages
  package:
    name: "*"
    state: latest

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🔥 Final Tips for Your Infosys DevOps Consultant Interview

✅ Master Troubleshooting – Be ready to debug connectivity, SSH, playbook failures. ✅ Know Real-World Scenarios – Be prepared to discuss Ansible best practices. ✅ Practice Writing Playbooks – They might ask you to write or modify one in the interview. ✅ Stay Confident! – Answer like a Senior DevOps Engineer with structured, real-world solutions.

🚀 Need more questions or detailed answers? Let me know! 🚀