100+ AWS Devops Engineer Interview Questions and Answers

To build a Docker image from a Dockerfile, use the 'docker build' command.

• Navigate to the directory containing the Dockerfile

• Run the command 'docker build -t .'

• The '.' at the end of the command specifies the build context

• The '-t' flag is used to tag the image with a name and optional tag

A launch template is a pre-configured set of Amazon Machine Images (AMIs), instance types, and other settings used to launch EC2 instances.

• Launch templates simplify the process of launching EC2 instances by providing a pre-configured set of settings.

• They can be used to launch instances in an Auto Scaling group or individually.

• Launch templates can be versioned and updated to reflect changes in the desired configuration.

• They can also be shared across AWS accounts and regions.

• La...read more

AWS CodePipeline is the CI/CD tool in AWS.

• AWS CodePipeline is a fully managed continuous delivery service

• It automates the build, test, and deploy phases of your release process

• It integrates with other AWS services like CodeCommit, CodeBuild, and CodeDeploy

• It supports various third-party tools like Jenkins, GitHub, and Bitbucket

Terraform is an infrastructure as code tool used to provision and manage cloud resources.

• Automates infrastructure deployment

• Supports multiple cloud providers

• Enables version control for infrastructure

• Allows for modular and reusable code

• Facilitates collaboration between teams

• Examples: provisioning EC2 instances, creating S3 buckets, managing DNS records

Terraform state file is a file that stores the state of your infrastructure managed by Terraform.

• It keeps track of the current state of your resources in the cloud.

• Helps Terraform understand what has been created, modified, or deleted.

• It is used to plan and apply changes to your infrastructure.

• State file can be stored locally or remotely in a backend like AWS S3 or Terraform Cloud.

DevOps is a software development methodology that combines software development (Dev) with IT operations (Ops) to shorten the systems development life cycle.

• Collaborating with developers, system admins, and other stakeholders to automate and streamline the software delivery process

• Implementing continuous integration and continuous deployment (CI/CD) pipelines

• Monitoring and maintaining the infrastructure and applications in production

• Using tools like Docker, Kubernetes, Jenkin...read more

Command to find disk utilization in Linux?

• Use 'df' command to display disk space utilization

• Use '-h' option to display sizes in human-readable format

• Use '-T' option to display file system type

• Use '-x' option to exclude certain file system types

• Example: 'df -hT -x tmpfs -x devtmpfs'

CodePipeline is a continuous integration and continuous delivery service for fast and reliable application and infrastructure updates.

• Automates the build, test, and deploy phases of your release process

• Supports integration with various AWS services like CodeBuild, CodeDeploy, and Lambda

• Allows for custom actions and third-party integrations

• Provides visualization of the entire release process with customizable dashboards

Roles in Ansible are a way to group tasks, handlers, variables, and other related files together for easier management and reuse.

• Roles help in organizing and structuring Ansible playbooks.

• They promote reusability and modularity by allowing tasks to be grouped together.

• Roles can be shared and reused across different playbooks.

• Each role typically consists of directories like tasks, handlers, templates, vars, and defaults.

• Roles can be installed using Ansible Galaxy or manually c...read more

Kubernetes pod creation and replicaset events in Kubernetes Ingress controller.

• Pod creation involves defining a pod specification in a YAML file and using 'kubectl create' command to create the pod.

• Replicaset events can be monitored using 'kubectl describe replicaset' command to check for events related to the replicaset.

• Ingress controller manages external access to services in a Kubernetes cluster by routing traffic based on rules defined in the Ingress resource.

• Events relat...read more

I am familiar with various DevOps tools such as Jenkins, Ansible, Docker, Kubernetes, Git, and AWS services.

• Jenkins for continuous integration and continuous delivery

• Ansible for configuration management and automation

• Docker and Kubernetes for containerization and orchestration

• Git for version control

• AWS services such as EC2, S3, Lambda, and CloudFormation for cloud infrastructure management

To ensure high availability and scalability during deploying an application, utilize load balancing, auto-scaling, fault tolerance, and monitoring.

• Implement load balancing to distribute traffic evenly across multiple servers.

• Utilize auto-scaling to automatically adjust the number of instances based on traffic demand.

• Design for fault tolerance by using redundant components and failover mechanisms.

• Monitor the application and infrastructure for performance issues and scale proac...read more

git fetch downloads changes from the remote repository, while git pull downloads changes and merges them into the current branch.

• git fetch only downloads changes from the remote repository, but does not merge them into the current branch

• git pull downloads changes from the remote repository and merges them into the current branch

• git fetch is useful for reviewing changes before merging, while git pull is a shortcut for fetching and merging in one command

A NAT gateway is a managed network address translation service provided by AWS.

• It allows instances in a private subnet to connect to the internet or other AWS services.

• It provides better availability and bandwidth than a NAT instance.

• It automatically scales to meet traffic demands.

• It can be used to reduce the attack surface of instances in a private subnet.

• It can be used to access resources in a VPC from a remote network.

AWS Lambda is a serverless computing service that runs code in response to events and automatically manages the computing resources required.

• Lambda functions are triggered by events such as changes to data in an S3 bucket, updates to a DynamoDB table, or HTTP requests via API Gateway.

• Lambda functions can be written in languages like Node.js, Python, Java, and more.

• AWS Lambda automatically scales to handle the incoming traffic and only charges for the compute time used.

Bash is a command language interpreter for Unix-like operating systems.

• Bash stands for Bourne Again SHell.

• It is the default shell for most Unix-like systems.

• Bash allows users to execute commands, write scripts, and automate tasks.

• It supports features like command substitution, variables, loops, conditionals, and functions.

• Bash scripts have a .sh file extension.

Docker is a containerization platform used to package and run applications, while Ansible is a configuration management tool used for automating IT infrastructure tasks.

• Docker is used to create containers that encapsulate an application and its dependencies, providing a lightweight and portable environment.

• Ansible is used for automating tasks such as configuration management, application deployment, and orchestration of IT infrastructure.

• Docker containers are isolated environ...read more

DevOps is a software development approach that combines development and operations to improve collaboration and efficiency.

• DevOps aims to automate and streamline the software development lifecycle.

• Real-time use cases include continuous integration and delivery, infrastructure as code, and monitoring and logging.

• CI/CD pipelines enable frequent and reliable software releases.

• Infrastructure as code allows for version-controlled and automated infrastructure provisioning.

• Monitorin...read more

IAM role is used to grant permissions to entities, while IAM group is used to group users with similar permissions.

• IAM role is used to delegate permissions to entities like EC2 instances or Lambda functions

• IAM group is used to group users with similar permissions for easier management

• IAM role can be assumed by trusted entities, while IAM group is used for managing user permissions

Code to check if a given number is prime or not.

• Iterate from 2 to square root of the number and check for divisibility.

• If the number is divisible by any number other than 1 and itself, it is not prime.

• Return true if the number is prime, false otherwise.

The current project architecture is a microservices-based system deployed on AWS using Docker containers and Kubernetes for orchestration.

• Microservices architecture with separate services for different functionalities

• Docker containers used for packaging and deploying each microservice

• Kubernetes used for container orchestration and scaling

• AWS services like EC2, S3, RDS, and Lambda used for various components

• Load balancers for distributing traffic among microservices

Kubernetes architecture consists of master nodes and worker nodes, with components like API server, scheduler, controller manager, and kubelet.

• Kubernetes architecture follows a master-slave model.

• Master nodes manage the cluster and worker nodes run applications.

• Key components include API server, scheduler, controller manager, and kubelet.

• Nodes communicate with each other through the kube-api server.

• ETCD is used for storing configuration data.

S3 is a scalable object storage service provided by AWS. fs tab is a configuration file used to mount file systems in Linux.

• S3 disadvantages: eventual consistency, limited metadata search capabilities, and data retrieval costs.

• fs tab disadvantages: incorrect configuration can cause system boot failure, security risks if not properly secured, and can be difficult to manage in large environments.

Trust policy in IAM defines which entities are trusted to assume roles in AWS

• Trust policy is a JSON policy document that defines which entities (accounts, users, roles) are trusted to assume roles in AWS

• It is attached to the IAM role and specifies the trusted entities by their AWS account ID or by using the 'aws' principal

• Trust policies are used to establish trust relationships between different AWS accounts or services

• Example: {"Effect": "Allow", "Principal": {"AWS": "arn:aw...read more

Exposing the application can be done through API Gateway, Load Balancer, or directly through public IP.

• Use API Gateway to expose RESTful APIs securely

• Utilize Load Balancer for distributing traffic across multiple instances

• Expose the application directly through a public IP address

• Implement security measures such as SSL certificates and firewalls

EC2 is a virtual server in AWS cloud. S3 is a scalable object storage service.

• EC2 stands for Elastic Compute Cloud and provides resizable compute capacity in the cloud.

• S3 stands for Simple Storage Service and provides scalable object storage for data backup, archival, and analytics.

• EC2 instances can be launched in different sizes and configurations based on the user's requirements.

• S3 allows users to store and retrieve any amount of data from anywhere in the world.

• Both EC2 and...read more

Best practices for setting up and using Prometheus and Grafana for monitoring and visualization.

• Use Prometheus for collecting metrics and Grafana for visualizing them.

• Set up alerting in Prometheus to notify of any issues.

• Use labels and tags effectively to organize metrics in Grafana.

• Regularly review and optimize queries and dashboards for performance.

• Implement security best practices to protect sensitive data.

• Regularly update Prometheus and Grafana to ensure they are running ...read more

Kubernetes pod is the smallest deployable unit in Kubernetes that represents a single instance of a running process.

• Pods can contain one or more containers that share resources like storage and network.

• Pods are scheduled onto nodes in a Kubernetes cluster.

• Pods are mortal, meaning they can be created, destroyed, and replaced by the Kubernetes system.

• Pods can be managed using controllers like Deployments, StatefulSets, and DaemonSets.

Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications.

• Kubernetes is used to manage and automate the deployment of containerized applications.

• It provides a platform for running and scaling applications across a cluster of machines.

• Kubernetes ensures high availability and fault tolerance by automatically restarting failed containers.

• It allows for easy scaling of applications by adding o...read more

Dockerfile is a text document that contains all the commands a user could call on the command line to assemble an image.

• Dockerfile is used to build Docker images by specifying a series of instructions.

• It includes commands like FROM, RUN, COPY, CMD, etc.

• Each instruction in the Dockerfile creates a layer in the image.

• Dockerfile is used to automate the process of creating Docker containers.

• Example: FROM ubuntu:latest, RUN apt-get update, CMD ["echo", "Hello World"]

Creating a Jenkins job using an image in Docker

• Create a Dockerfile with necessary configurations for Jenkins job

• Build a Docker image using the Dockerfile

• Run a Jenkins container using the Docker image

• Configure Jenkins job to use the Docker image as the build environment

CI/CD is the process of continuous integration and continuous delivery/deployment.

• In our project, we use Jenkins as our CI/CD tool.

• Every time a developer pushes code to the repository, Jenkins automatically builds and tests the code.

• If the build and tests pass, Jenkins deploys the code to a staging environment for further testing.

• Once the code is approved in staging, Jenkins deploys it to production.

• This process ensures that code changes are thoroughly tested and deployed qui...read more

Cloud services refer to on-demand delivery of computing resources over the internet.

• Cloud services allow users to access and use resources like servers, storage, databases, networking, software, and analytics without the need for physical infrastructure.

• Examples of cloud services include Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform, and IBM Cloud.

• Cloud services offer scalability, flexibility, cost-effectiveness, and the ability to quickly deploy applicati...read more

Error encountered during pod creation can be due to various reasons such as incorrect configuration, resource constraints, network issues, or image availability.

• Check the pod configuration file for any syntax errors or misconfigurations

• Ensure that there are enough resources available on the cluster for pod creation

• Verify network connectivity and DNS resolution within the cluster

• Check if the container image specified in the pod configuration is available and accessible

Docker build is a command used to create a Docker image from a Dockerfile.

• Docker build is used to automate the creation of Docker images.

• It uses a Dockerfile to define the image's contents and configuration.

• The Dockerfile is a text file that contains instructions for building the image.

• The build process involves downloading dependencies, installing packages, and configuring the image.

• The resulting image can be used to create Docker containers.

• Example: docker build -t myimage ...read more

The 'add' command is used to add files from the source directory to the destination directory in a Dockerfile, while the 'copy' command is used to copy files from the source directory to the destination directory in a Dockerfile.

• The 'add' command can also accept URLs as the source, while the 'copy' command cannot.

• The 'add' command can automatically extract compressed files, while the 'copy' command cannot.

• The 'copy' command is recommended over the 'add' command for copying lo...read more

Code to check if a given string is a palindrome or not.

• Create a function that takes a string as input.

• Remove all non-alphanumeric characters and convert the string to lowercase.

• Compare the original string with its reverse to check if it is a palindrome.

Docker is a containerization platform that allows applications to be packaged and run in isolated environments. DevOps is a software development methodology that focuses on collaboration, automation, and integration between development and operations teams.

• Docker is a tool designed to make it easier to create, deploy, and run applications by using containers.

• Containers allow a developer to package up an application with all parts it needs, such as libraries and other dependen...read more

DevOps architecture refers to the structure and design of tools, processes, and practices that enable collaboration between development and operations teams.

• DevOps architecture typically includes tools for automation, continuous integration/continuous deployment (CI/CD), monitoring, and collaboration.

• It involves breaking down silos between development and operations teams to enable faster delivery of software.

• Common components of DevOps architecture include version control sy...read more

There are three main types of clouds: public, private, and hybrid.

• Public cloud: Services are delivered over the internet and shared across multiple organizations. Example: AWS, Azure, Google Cloud.

• Private cloud: Services are maintained on a private network and dedicated to a single organization. Example: VMware, OpenStack.

• Hybrid cloud: Combination of public and private clouds, allowing data and applications to be shared between them. Example: AWS Outposts, Azure Stack.

Git is a version control system used for tracking changes in source code, while Subversion (SVN) is another version control system with similar features.

• Git is distributed, allowing for offline work and faster branching and merging.

• Subversion is centralized, requiring a network connection for most operations.

• Git uses a staging area for changes before committing, while Subversion commits changes directly to the repository.

• Git has a more complex branching and merging model comp...read more

Webhook is a method of augmenting or altering the behavior of a web page, or web application, with custom callbacks.

• Webhook is a way for an application to provide other applications with real-time information.

• It allows developers to receive instant notifications when a specific event occurs.

• Webhooks are commonly used in automation, continuous integration, and deployment processes.

• Examples include receiving notifications when a code repository is updated or when a payment is m...read more

Jenkins CI/CD flow automates the software delivery process from code commit to deployment.

• Jenkins pulls code from version control system

• Builds the code and runs automated tests

• If tests pass, deploys the code to a staging environment

• Manual testing is done in staging environment

• If approved, Jenkins deploys the code to production environment

• Logs and reports are generated throughout the process

Terraform is an infrastructure as code tool for building, changing, and versioning infrastructure safely and efficiently. Kubernetes is a container orchestration platform for automating deployment, scaling, and management of containerized applications.

• Terraform is used for infrastructure provisioning and management.

• Kubernetes is used for container orchestration and management.

• Terraform uses declarative configuration files to define infrastructure.

• Kubernetes uses YAML files to...read more

VPC stands for Virtual Private Cloud, which is a virtual network dedicated to your AWS account.

• VPC allows you to create a logically isolated section of the AWS Cloud where you can launch resources in a virtual network.

• You can define your own IP address range, create subnets, configure route tables, and network gateways within a VPC.

• VPC helps in controlling which resources are exposed to the internet and which remain private.

• It provides security by allowing you to set up secur...read more

Terraform is an open-source infrastructure as code software tool created by HashiCorp.

• Terraform allows users to define and provision infrastructure using a declarative configuration language.

• It supports multiple cloud providers such as AWS, Azure, and Google Cloud Platform.

• Infrastructure is defined in Terraform configuration files, which describe the desired state of the infrastructure.

• Terraform then creates an execution plan to reach the desired state and executes it to prov...read more

Nacl is a stateless firewall while security group is a stateful firewall in AWS.

• NACL operates at the subnet level, while security groups operate at the instance level.

• NACL rules are evaluated in order, while security group rules are evaluated independently.

• NACLs are stateless, meaning you must create rules for both inbound and outbound traffic, while security groups are stateful.

• NACLs are more flexible in terms of allowing or denying traffic based on IP addresses, while secur...read more