Are you a DevOps engineer or thinking about becoming one? If that’s the case, you’ve come to the correct place. In this blog post, I have listed the top possible questions asked in interviews for roles in DevOps. We’ll also provide you with some tips on how to answer these questions. So you can ace your following interview and successfully get that dream job.
If you want to improve your DevOps skills thoughtfully and systematically and become certified as a DevOps Engineer, we would be glad to help you. Once you finish the DevOps Courses, we guarantee that you will be capable of handling a variety of DevOps opportunities available in the industry.
What are the requirements to become a DevOps Engineer?
Organizations will look for a clear set of skills when filling out DevOps roles. The most important of these are:
- Experience with infrastructure automation tools like Ansible, Chef, Puppet, SaltStack, or Windows PowerShell DSC.
- Fluency in web languages like Python, Ruby, or Java.
- Interpersonal skills that allow you to communicate and cooperate with people from different teams and jobs.
If you have the above skills, you are ready to begin preparing for your DevOps interview! If not, don’t worry – our DevOps Courses will help you master DevOps.
These are the most common questions asked in a DevOps job interview:
Q1. What is DevOps?
DevOps is a term for a set of practices that combine software development (Dev) and information technology operations (Ops) to streamline the delivery of software products and services.
Development and operations teams work together in a DevOps environment to complete tasks and projects more efficiently. This collaboration often leads to faster software delivery, improved quality and reliability, and better communication and collaboration between teams.
As technology progresses, the need for DevOps has become increasingly important. DevOps is a set of practices that aim to automate the process of software delivery and infrastructure management.
With the help of DevOps, businesses can speed up the software delivery process while improving the quality of their software products. In addition, DevOps can help reduce the risk of errors and improve the overall stability of IT systems.
There are many benefits of DevOps, but the three most important ones are:
1. Improved efficiency
2. Increased quality
3. Reduced risk
DevOps is a software development approach emphasizing collaboration between development and operations teams. In a DevOps model, both teams work together throughout the software development lifecycle, from planning to development to testing to deployment.
|git init||Used to create a new git repository|
|git clone||Used to copy a code repository from a remote server to your local machine.|
|git add||It is used to add one or more files to the staging area.|
|git commit||Commits changes to the git repository|
|git status||It shows the status of the current git repository|
|git branch||Lists create or delete branches|
|git merge||Merges branches together|
|git push||Pushes changes to a remote git repository|
|git pull||Pulls changes from a remote git repository|
|git checkout||Checks out a branch or file|
|git mv||Move or rename a file|
|git rm||Remove files from the working directory|
|git log||Show commit logs|
Q27. What is Docker?
Docker is a containerization tool that allows developers to create, deploy, and run applications within a container. A container is a self-contained software unit that includes everything needed to run an application, such as code, runtime, system tools, system libraries, etc.
Docker containers are lightweight, stand-alone, executable packages of software that include everything needed to run an application, such as code, runtime, system libraries, system tools, etc.
A Docker image is a read-only template that contains a set of instructions for creating a Docker container. It includes everything needed to run an application–the code, a runtime, dependencies, environment variables, and configuration files.
A Dockerfile is a text file containing all the instructions a user may use on the command line to create an image. Using a Dockerfile, users can create and deploy new images.
Docker swarm is a container orchestration tool that allows you to manage and deploy your containers across multiple hosts. With swarm, you can easily create a scalable and highly available container environment.
If you want to list all of the containers currently running, you can use the ‘docker ps’ command. This will give you a list of all the running containers and some basic information about each one.
If you want to stop and restart the Docker container, you can use the “docker stop <container ID>” and “docker start <container ID>” commands.
First, you’ll need to find the container ID of the container you want to stop. You can do this by running the “docker ps” command.
Q34. How many containers can run per host?
The number of containers that can run on a single host depends on a few factors, including the host’s CPU and memory resources and the size and number of containers. Generally, a host can support a few hundred containers.
Q35. What is the difference between the ADD and COPY commands in a Dockerfile?
Two key differences exist between the ADD and COPY commands in a Dockerfile. The first is that ADD can be used to fetch files from remote locations, whereas COPY can only be used to copy files from the build context. The second difference is that ADD automatically unpacks compressed files, whereas COPY does not.
Q36. What are some basic Docker commands?
Some basic Docker commands are:
1) docker push: pushes an image or repository to a registry
2) docker ps: List all of the running Docker containers
3) docker build: Build a Docker image from a Dockerfile
4) docker run: Runs a container from an image
5) docker pull: Pulls an image or repository from a registry
6) docker start: Starts one or more Docker containers
7) docker stop: Stops one or more running Docker containers
8) docker search: Searches for an image in the Docker hub
9) docker commit: Commits a new image
Q37. What is Ansible?
Ansible is an open-source IT Configuration Management, Deployment & Orchestration tool. It is used to set up and manage infrastructure and applications. It enables users to deploy and update applications using SSH without installing an agent on a remote system.
Q38. What is Ansible Playbook?
Ansible Playbook is a configuration management tool used to manage server configurations and deployments. It is written in the YAML format and consists of a series of rules or tasks that need to be executed on a remote server.
Q39. What is Ansible Galaxy?
This is a tool bundled with Ansible to create a base directory structure. Galaxy is a website that lets users find and share Ansible content. You can use this command to download roles from the website:
$ ansible-galaxy install username.role_name
Q40. What is an ad hoc command?
An ad hoc command is a simple, one-time command used to perform a specific task. Ad hoc
Commands are often used when you fix a problem or quickly perform a quick action without using a playbook.
Q41. What are Ansible tasks?
Ansible tasks are a set of instructions or commands you want Ansible to execute on your remote servers. They are written in YAML syntax and are typically used to automate server configuration or application deployment.
Q42. Which protocol does Ansible use to connect with Linux and Windows?
For Linux, Ansible uses the SSH protocol to communicate with Linux systems.
For Windows, Ansible uses the WinRM protocol to communicate with Windows systems.
Q43. What is a YAML file and how do we use it in Ansible?
A YAML file is a text file that contains data in a structured format. YAML stands for “YAML Ain’t Markup Language.”
Ansible uses YAML because it is very easy to read and write. It is also easy to understand for computers.
In Ansible, we use YAML files to describe our infrastructure. We can use YAML files to describe our servers, networks, software, and services.
Q44. What are Ansible Variables?
Ansible variables help you define and customize your playbooks. They can specify configuration settings, user options, and other data. You can use variables in your playbooks to make them more flexible and reusable.
Ansible variables are used to store values that can be used in playbooks and templates.
There are two types of variables in Ansible:
1. play vars: these are variables that are set at the start of a play
2. host vars: these are variables that are set for a specific host
Q45. What are the Ansible Server requirements?
- To run Ansible, you need a Linux server with SSH access. This can be a remote server or a local VM.
- The server should have a minimum of 2GB of RAM.
- And it requires a python 2.6 version or higher.
Q46. What are Ansible Vaults, and why are they used?
Ansible Vault is a feature that allows you to keep all of your secrets secure. They can store sensitive data, such as passwords, API keys, and other confidential information.
They are encrypted using a strong cipher so that even if someone gains access to the vault file, they will not be able to read the contents.
Vaults are essential to securing Ansible playbooks and ensuring that only authorized users can access sensitive data.
Q47. What is a Chef?
Chef is a Configuration management tool that maintains the infrastructure by writing code rather than using a manual method so that it can be automated, tested, and deployed very quickly. Chef has Client-server architecture and supports multiple platforms like Windows, Ubuntu, Centos, and Solaris. It can also be integrated with cloud platforms like AWS, Google Cloud Platform, Open Stack, etc.
Q48. What is Recipe in Chef?
A recipe in Chef is a set of instructions that tells Chef how to configure and manage a server. Recipes are written in a Ruby DSL (domain-specific language). They are stored in files called cookbooks.
Recipes can be used to install and update software, create and manage files, and much more. In essence, a recipe is a way to automate server administration tasks.
Q49. What is the difference between a recipe and a cookbook in Chef?
A chef recipe is a combination of resources for configuring a software package. A chef’s recipe is also ideal for configuring a certain part of the infrastructure. However, a Cookbook is a collection of Chef Recipes. Also, a Chef cookbook contains supporting information that improves the ease of configuration management
Q50. Explain the use of a Knife in Chef.
A knife is a command-line tool that acts as an interface between the Chef Workstation and Chef Server. It helps the Chef Workstation communicate the content of its chef-repository directory with a Chef Server. Chef-Workstation contains the chef-repository directory where cookbooks, roles, data bags, and environments are stored.
With Knife commands, users can manage (create, delete, list, edit) nodes, roles, JSON data storage, environments, cookbooks and recipes, and cloud resources using Knife plug-ins.
Q51. Explain metadata.rb in Chef.
When you create a cookbook, one of the files that is generated is called metadata.rb. This file contains important information about the Cookbook, such as its name, version, maintainer, and dependencies.
The metadata.rb file is available in Cookbook’s directory. When Cookbook is uploaded to Chef Infra Server, or command knife cookbook metadata is run, metadata.rb file gets compiled and saved as JSON data in the Cookbook.
Q52. Why are SSL certificates used in Chef?
- SSL certificates are used between the Chef server and the client to verify that each node has access to the correct data.
- Every node has a pair of private and public keys. The public key is stored on the Chef server.
- When an SSL certificate is sent to the server, it will contain the node’s private key.
- The server compares this to the public key to identify the node and give the node access to the required data.
Q53. What is Puppet?
Puppet is a free, open-source configuration management tool that helps you automate your infrastructure’s provisioning, configuration, and deployment.
Q54. What are Manifest files in Puppet?
Manifest files in Puppet are used to define the desired state of your system. In other words, they specify what resources should be present on your system and what state those resources should be in.
Q55. Which is better Chef or Puppet?
If you’re looking for a more declarative and less code-heavy tool, then Puppet is probably a better choice. Or, if you’re looking for a tool that gives you more flexibility and control, Chef is a better bet.
Q56. Why puppet is used in DevOps?
Puppet is a configuration management tool that can help DevOps teams automate the provisioning and configuration of infrastructure. Puppet can help teams to easily and rapidly deploy changes to their environment while ensuring consistent and reliable results.
Puppet is also used to manage containers, as well as orchestrate and manage the deployment of applications.
Q57. What is Puppet Kick?
Puppet kick is a tool used by Puppet administrators to trigger Puppet runs on remote nodes. It can be used to trigger a Puppet run manually or to schedule a Puppet run in advance.
Q58. How to upgrade Puppet and Facter?
You can upgrade Puppet and Facter through your operating system (OS) package management system. You can do this through Puppet Labs’ public repositories or the vendor’s repository.
Q59. What is Puppet Labs?
Puppet Labs is a leading provider of configuration management software. Their products help organizations automate, keeping their systems and applications up-to-date and making it easier to deliver applications and services at scale.
Q60. What is Facter?
The Facter is a system profiling library that gathers system information during a Puppet run. The Facter offers your information regarding the IP address, kernel version, CPU, and others.
Q61. What are the three primary sources that puppet uses for compiling the catalog?
- External data
- Agent-provided data
- Puppet manifests
Q62. What is codedir in Puppet?
Codedir is a Puppet setting that specifies the directory where Puppet code is stored. This setting is important because it tells Puppet where to find your manifests and modules. By default, the codedir is set to /etc/puppetlabs/code.
Q63. Where does codedir locate Linux and Windows?
The codedir is located at
- Linux: /etc/dir/PuppetLabs/code
- Windows: C:\ProgramData\PuppetLabs\puppet\etc
Q64. What is Kubernetes?
Kubernetes is an open-source container orchestration tool that automates tasks such as managing, monitoring, scaling, and deploying containerized applications.
Q65. What is Container Orchestration?
Container orchestration is the process of automating the deployment, management, and scaling of containerized applications. This can include tasks such as container deployment, container networking, container storage, container security, and so on.
Q66. What are the features of Kubernetes?
1) Kubernetes can automatically discover and load balance your application services across a cluster.
2) Kubernetes will automatically pack your application containers onto the most efficient nodes in the cluster based on available resources.
3) Kubernetes can automatically restart failed containers and replicas and perform rolling updates to ensure that your applications are always up-to-date.
4) Kubernetes can automatically mount and manage persistent storage for your applications.
5) Kubernetes can help you manage and maintain your application’s configuration across multiple environments.
Q67. What is Google Container Engine?
Google Container Engine is a powerful and easy-to-use container orchestration tool from Google. It makes it easy to deploy and manage containers at scale on any Google Cloud Platform (GCP) infrastructure.
This Kubernetes-based engine supports only those clusters which run within Google’s public cloud services.
68. What is Minikube?
Minikube is a tool used to run Kubernetes locally. Minikube runs a single-node Kubernetes cluster inside a virtual machine on your laptop.
Q69. What is Kubectl?
Kubectl is a command line interface (CLI) for Kubernetes. It allows you to run commands against Kubernetes clusters. You can use kubectl to deploy applications, manage cluster resources, and inspect and view logs.
Q70. What is Kubelet?
Kubelet is a Kubernetes agent that runs on each node in the cluster. It is responsible for maintaining a set of pods and ensuring that the pods are healthy and running.
Q71. What are the different components of Kubernetes Architecture?
The Kubernetes Architecture has mainly two components – the master node and the worker node. As shown in the diagram below, the master and the worker nodes have many inbuilt components within them. The master node has the kube-api server, kube-controller-manager, kube-scheduler, etcd. At the same time, the worker node has kubelet and kube-proxy running on each node.
Q72. What is Kube-proxy?
Kube-proxy is a network proxy and load balancer solution. It is responsible for routing traffic to the container depending on IP and the port number. It is used to provide service abstraction used with other networking operations.
Q73. How to run Kubernetes locally?
Kubernetes can be run locally using the Minikube tool, which is a lightweight Kubernetes distribution that can be run on a single node cluster in a virtual machine (VM) on the computer. As a result, it is perfect for users who are just getting started with Kubernetes.
Q74. List out some important kubectl commands
The important kubectl commands that every Kubernetes user should know.
1. kubectl get: This command is used to get information about Kubernetes resources.
2. kubectl describe: This command gives you more information about a specific resource.
3. kubectl apply: This command is used to apply changes to a resource.
4. kubectl delete: This command is used to delete a resource.
5. kubectl scale: This command is used to scale a resource.
6. kubectl rollout: This command is used to rollout changes to a resource.
7. kubectl exec: This command is used to execute a command in a container.
8. kubectl port-forward: This command is used to forward traffic to a specific port.
9. kubectl logs: This command is used to get the logs of a container.
Q75. Why uses kube-apiserver?
kube-apiserver is the central component of a Kubernetes cluster, responsible for all the API calls, that is used to validate and configure API objects, which include controllers, services, etc. It provides the front end to the cluster’s shared region, using which components interact.
Q76. What is ContainerCreating pod?
A ContainerCreating pod can be scheduled on a node but can’t start up properly.
Q77. What is Kubernetes proxy service?
Kubernetes proxy service is a service that runs on the node and helps in making it available to an external host.
Q78. Why use a namespace in Kubernetes?
Namespaces in Kubernetes are used to divide cluster resources between users. It helps the environment where more than one user spreads projects or teams and provides a scope of resources.
Q79. Define Kubernetes controller manager
The Kubernetes controller manager is a daemon used for core control loops, garbage collection, and namespace creation. It allows the running of more than one process on the master node. The controller manager is Kubernetes’ primary process and is responsible for many things, such as:
– Keeping track of the cluster state
– Adding or removing nodes from the cluster
– Performing health checks on nodes
– Handling node failures
– Updating the routing table
– And more!
Q80. What is the role of a Load Balancer in Kubernetes?
A load balancer is responsible for distributing traffic evenly between the different nodes in a Kubernetes cluster. This ensures that no single node is overloaded and that the application can handle the load.
These are some of the most common DevOps interview questions and answers you might come across while attending an interview. If you are someone who has recently started your career in DevOps, you can take up our online courses and projects that will validate your knowledge and skills needed to be an expert in the field.
All the best for your interview!