Top 50 Configuration Management Interview Question and Answers

08 Oct 2024 - Shyam Mohan

1. What is configuration management?
   Configuration management is a process that systematically manages changes and configurations in a software environment to ensure consistency and accuracy across systems.

2. Why is configuration management important in DevOps?
   It enables DevOps teams to automate system setups, reduce errors, ensure consistency across environments, and improve collaboration and version control.

3. What are the benefits of using configuration management tools?
   They help with automation, consistency, disaster recovery, scaling infrastructure, and enforcing compliance across environments.

4. What are the popular configuration management tools?
   Popular tools include Ansible, Puppet, Chef, SaltStack, and Terraform.

5. What is Infrastructure as Code (IaC)?
   IaC is a practice of managing infrastructure through code, allowing for version control, automation, and deployment of configurations across environments.

6. How does configuration management differ from IaC?
   Configuration management focuses on the operational state and ongoing management, while IaC emphasizes defining infrastructure setup and deployment.

7. Explain idempotence in configuration management.
   Idempotence ensures that applying a configuration multiple times results in the same system state, preventing unexpected changes.

8. How does version control integrate with configuration management?
   Version control tracks configuration changes, enabling rollbacks, audits, and collaboration.

9. What is the difference between agent-based and agentless configuration management?
   Agent-based systems require a client agent installed on managed nodes (e.g., Chef), while agentless systems use protocols like SSH (e.g., Ansible).

10. What is continuous configuration automation?
    Continuous configuration automation is the practice of maintaining the desired state of infrastructure in a continuous integration/continuous deployment (CI/CD) workflow.

11. What is Ansible, and how does it work?
    Ansible is an open-source, agentless configuration management tool that uses playbooks (YAML files) to automate tasks over SSH.

12. Explain the structure of an Ansible playbook.
    An Ansible playbook consists of YAML files defining tasks, roles, variables, and handlers that manage the configuration.

13. What is an Ansible role?
    An Ansible role is a way to organize playbooks and tasks, making them reusable and modular.

14. How do you manage variables in Ansible?
    Variables can be defined in the inventory, playbooks, or group and host variables files for more flexibility.

15. What are Ansible modules?
    Modules are reusable scripts used to accomplish tasks like managing files, packages, and users on remote systems.

16. How does Ansible ensure idempotency?
    Ansible modules are designed to check the current state before making changes, ensuring idempotency.

17. What is the purpose of an Ansible inventory file?
    The inventory file lists managed hosts and groups, enabling targeted configurations across environments.

18. How do you execute ad-hoc commands in Ansible?
    You can use ansible commands with module flags to execute tasks on remote hosts without a playbook.

19. What is a handler in Ansible?
    A handler is a task triggered by a notification from another task, typically used for restarting services after changes.

20. How does Ansible Vault work?
    Ansible Vault encrypts sensitive data like passwords, keys, and variables to protect them in playbooks and roles.

21. What is Puppet, and how does it work?
    Puppet is a configuration management tool that uses a client-server architecture to enforce configurations across systems using a declarative language.

22. What are Puppet manifests?
    Manifests are files in Puppet where the configuration code is written, often using a .pp extension.

23. What is a Puppet module?
    A module in Puppet is a collection of manifests, files, templates, and tasks organized for reusability.

24. How does Puppet ensure idempotency?
    Puppet’s declarative syntax enables it to apply the same configuration multiple times without causing unexpected changes.

25. What is Hiera in Puppet?
    Hiera is a key-value lookup tool in Puppet used to manage variables across different environments.

26. Explain how Puppet uses resources.
    Resources in Puppet define the desired state of an element (e.g., user, file, package) and include properties like name and type.

27. How does Puppet manage dependencies?
    Puppet allows you to define dependencies between resources, ensuring they execute in the correct order.

28. What is the Puppet Forge?
    Puppet Forge is an online repository where users can find and share pre-built modules.

29. How do you use environment-specific configurations in Puppet?
    You can set up separate environments in Puppet, each with specific manifests and modules to reflect different configurations.

30. How does Puppet manage sensitive data?
    Puppet integrates with tools like Hiera and modules like hiera-eyaml for encrypting and managing sensitive data.

31. What is Chef, and how does it work?
    Chef is a configuration management tool that uses Ruby-based “recipes” to define the state of infrastructure and maintain idempotency.

32. What is a Chef recipe?
    A recipe in Chef is a set of resources used to configure specific system states and manage applications.

33. What is a Chef cookbook?
    A Chef cookbook is a collection of recipes, attributes, files, and templates to configure complex environments.

34. Explain Chef nodes.
    Nodes are individual systems managed by Chef, each representing a physical or virtual machine in the infrastructure.

35. What is the Chef Supermarket?
    Chef Supermarket is an online repository for sharing and downloading community cookbooks.

36. How does Chef handle dependencies?
    Chef uses a dependency resolver to handle cookbook dependencies, ensuring that all required components are available.

37. What is the difference between Chef client and Chef server?
    Chef client is installed on managed nodes, while Chef server is the central management server that stores configurations and data.

38. What is Ohai in Chef?
    Ohai is a tool in Chef that collects system information and stores it on the Chef server for configuration purposes.

39. How does Chef ensure idempotency?
    Chef’s declarative approach ensures that each resource converges to the desired state without repeated changes.

40. How do you use data bags in Chef?
    Data bags are used to store global variables like usernames and passwords in JSON format, often encrypted for security.

41. What is SaltStack, and how does it work?
    SaltStack is a configuration management tool that uses a master-agent architecture for managing infrastructure state and remote execution.

42. What are Salt States?
    Salt States define the configuration of a SaltStack-managed environment and contain the desired state of a system.

43. Explain the Salt Master and Salt Minion.
    The Salt Master is the central server, while Salt Minions are agents on managed nodes that communicate with the master.

44. How does SaltStack ensure idempotency?
    SaltStack modules are designed to only make changes if the system deviates from the defined state.

45. What is a Salt Pillar?
    A Salt Pillar stores configuration data that is securely delivered to Salt Minions, allowing for targeted configurations.

46. What is the purpose of the Salt Event Bus?
    The event bus in SaltStack enables real-time event-driven automation and orchestration.

47. How do you use grains in SaltStack?
    Grains are system-specific information about minions, used to apply targeted configurations based on attributes.

48. What is Salt SSH?
    Salt SSH allows SaltStack to manage systems without installing a Salt Minion, using SSH for agentless management.

49. Explain Jinja in SaltStack.
    Jinja is a templating engine used in Salt to dynamically generate configuration files based on variables and conditions.

50. How does SaltStack manage sensitive data?
    SaltStack integrates with external vaults and uses pillars with encryption to securely manage sensitive data.