100+ Senior Devops Engineer Interview Questions and Answers

DevOps pipeline design involves creating a streamlined process for continuous integration and delivery of software.

• Identify the needs and goals of the organization

• Select appropriate tools and technologies for automation

• Design a workflow that includes build, test, deploy, and monitoring stages

• Implement version control and code review processes

• Integrate security and compliance measures

• Continuously optimize and improve the pipeline

Docker is used for containerization of applications, allowing for easy deployment and scaling. Before Docker, CI/CD integration was more complex and less efficient.

• Docker is used to create lightweight, portable, self-sufficient containers that can run applications in any environment.

• Before Docker, CI/CD pipelines often relied on virtual machines or manual configurations for deployment and testing.

• Docker simplifies the process of packaging applications and their dependencies, ...read more

Migrating on-premise infrastructure to a public cloud involves careful planning and execution.

• Assess current on-premise infrastructure and identify workloads to be migrated

• Choose a suitable public cloud provider based on requirements and budget

• Create a migration plan including timelines, resources, and potential risks

• Implement necessary changes such as network configurations, security settings, and data migration

• Test the migrated workloads thoroughly before fully transitionin...read more

To safeguard data and services, I would implement encryption, access controls, regular backups, and monitoring.

• Implement encryption for data at rest and in transit

• Set up access controls to restrict unauthorized access

• Regularly backup data to prevent data loss

• Implement monitoring and alerting to detect and respond to security incidents

Automate the process of adding mount points on system restart and store Terraform state file for accessibility by other developers.

• Use a configuration management tool like Ansible to automatically add mount points on system restart.

• Utilize cloud storage services like AWS S3 or Azure Blob Storage to store Terraform state file for easy access by other developers.

• Implement scripts or automation workflows to handle the mounting of storage volumes and managing Terraform state file...read more

Snapshot in Maven is a version of a project that is still in development and not yet released.

• Snapshots are versions of a project that are still in development and not yet released.

• They are identified by the suffix '-SNAPSHOT' in the version number.

• Snapshots can be deployed to a Maven repository for sharing with other developers for testing purposes.

• They are not intended for production use as they are subject to frequent changes.

The master switch in Exadata can be identified by checking the status of the cell server software.

• Check the status of the cell server software using the 'cellcli' command

• The cell server with the 'MS' role is the master switch

• The master switch can also be identified by checking the 'cellinit.ora' file

Spine switch and leaf switch are networking components in Exadata used for connecting database servers and storage servers.

• Spine switch acts as the core of the network, connecting all leaf switches and providing high-speed connectivity.

• Leaf switches connect database servers and storage servers to the spine switch, facilitating communication between them.

• Exadata uses a leaf-spine network architecture for efficient data transfer and scalability.

• Spine switches typically have hig...read more

LVM stands for Logical Volume Manager and is a tool used for managing disk storage in Linux servers.

• LVM allows for dynamic resizing of logical volumes without downtime.

• It provides features like snapshots, striping, mirroring, and thin provisioning.

• LVM is commonly used in server environments to manage storage efficiently.

• Example: Creating a new logical volume, resizing an existing logical volume.

Create a k8s deployment ymal with rolling update for a given docker image

• Define a Deployment object in the YAML file

• Specify the container image in the spec section

• Set the update strategy to RollingUpdate

• Define the number of replicas for the deployment

Git is a distributed version control system used for tracking changes in source code. Ansible is an open-source automation tool.

• Git is used for version control, allowing multiple developers to collaborate on a project

• Git tracks changes to files and allows for easy branching and merging

• Ansible is a configuration management and automation tool

• Ansible uses a declarative language to define system configurations and tasks

• Ansible can be used to automate the deployment and managemen...read more

Yes, I have managed devops infra in my previous roles.

• I have experience managing infrastructure using tools like Ansible, Terraform, and Kubernetes.

• I have also worked on building CI/CD pipelines using Jenkins and GitLab.

• In my previous role, I managed a large-scale AWS infrastructure for a SaaS product.

• I have experience with monitoring tools like Prometheus and Grafana.

• I have also worked on implementing security best practices in the infrastructure.

Ingress is a Kubernetes resource that manages external access to services, and a sidecar container is a secondary container that runs alongside the main container in a pod.

• Ingress is a Kubernetes resource that acts as an API gateway for incoming traffic to services within the cluster.

• Ingress controllers are responsible for implementing the rules specified in the Ingress resource.

• Sidecar containers are additional containers within a pod that provide supporting features such as...read more

CentOS/RHEL 6 & 7 differ in kernel version, package management, systemd, and support lifecycle.

• Kernel version: CentOS/RHEL 6 uses kernel version 2.6.x while CentOS/RHEL 7 uses kernel version 3.x.

• Package management: CentOS/RHEL 6 uses yum for package management, while CentOS/RHEL 7 uses yum and dnf.

• Systemd: CentOS/RHEL 6 uses SysV init system, while CentOS/RHEL 7 uses systemd as the init system.

• Support lifecycle: CentOS/RHEL 6 has reached end of life, while CentOS/RHEL 7 is st...read more

ext is the default file system for many Linux distributions, while xfs is known for better performance and scalability.

• ext is the default file system for many Linux distributions

• xfs is known for better performance and scalability

• xfs supports larger file systems and files compared to ext

Cloud migration process involves moving data, applications, and other business elements to a cloud computing environment.

• Assess current infrastructure and applications to determine what can be migrated to the cloud

• Choose the right cloud provider and services based on business needs and requirements

• Plan the migration process including timelines, resources, and potential risks

• Execute the migration process by transferring data, applications, and configurations to the cloud

• Test t...read more

Integrating tools in Jenkins pipeline involves using plugins and scripting

• Install necessary plugins for the tools you want to integrate

• Use Jenkinsfile to define the pipeline stages and include steps for tool integration

• Leverage Jenkins shared libraries for reusable code across pipelines

• Utilize Jenkins pipeline syntax for scripting custom integrations

Terraform is used for both infrastructure and application deployments.

• Terraform allows for defining infrastructure as code, making it easy to manage and deploy infrastructure resources.

• It can also be used to deploy applications by defining the necessary configurations and dependencies.

• Terraform supports various cloud providers such as AWS, Azure, and Google Cloud, making it versatile for different deployment scenarios.

Docker network group is a way to group containers together and isolate them from other containers on the same network.

• Docker network group allows containers to communicate with each other securely.

• Containers in the same network group can access each other using their container names.

• Network groups can be created using Docker network commands like 'docker network create'.

CI-CD pipeline is a process of continuous integration, testing, and deployment of code using tools like Jenkins, GitHub, Docker, Kubernetes, and Ansible.

• CI-CD pipeline automates the software delivery process

• Jenkins is a popular open-source automation server used for building, testing, and deploying code

• GitHub is a web-based platform for version control and collaboration

• Docker is a containerization platform used to package applications and their dependencies

• Kubernetes is an op...read more

A Dockerfile is a script that contains instructions to build a Docker image.

• Start with a base image

• Add necessary dependencies and packages

• Copy application code into the image

• Set environment variables

• Expose necessary ports

• Define the command to run the application

• Build the image using 'docker build' command

To configure Veracode with ADO, you can write a script that automates the process of setting up the integration.

• Use Veracode API to authenticate and interact with Veracode services

• Create a script that retrieves Veracode API credentials from ADO secure variables

• Automate the process of configuring Veracode settings in ADO pipelines

CI/CD pipeline is a set of automated processes that allow developers to deliver code changes more frequently and reliably.

• CI/CD stands for Continuous Integration/Continuous Delivery.

• CI involves automatically building and testing code changes frequently to catch errors early.

• CD involves automatically deploying code changes to production after passing tests.

• CI/CD pipelines typically include stages like build, test, deploy, and monitor.

• Popular CI/CD tools include Jenkins, GitLab...read more

Master-slave architecture is a design pattern where one device or process controls one or more other devices or processes.

• Master device/process controls the slave device/process

• Master device/process is responsible for distributing tasks to the slave devices/processes

• Slave devices/processes report back to the master device/process

• Commonly used in distributed computing, database replication, and networking

• Examples include MySQL replication, Jenkins master-slave setup, and Hadoo...read more

CI/CD process in Jenkins automates the building, testing, and deployment of software.

• Developers commit code changes to a version control system.

• Jenkins pulls the code and builds it in a clean environment.

• Automated tests are run to ensure code quality.

• If tests pass, the code is deployed to a staging environment for further testing.

• If staging tests pass, the code is deployed to production.

• Jenkins also provides feedback on build status and alerts on failures.

To ensure HA in ELK, utilize multiple nodes, load balancers, and data replication.

• Set up multiple Elasticsearch nodes in a cluster for redundancy

• Use load balancers to distribute traffic evenly across nodes

• Implement data replication to ensure data availability in case of node failure

Store ansible secrets securely and trigger pipeline after another

• Use ansible-vault to encrypt sensitive data like passwords and API keys

• Store encrypted secrets in a separate file or in a secure vault

• Use ansible-playbook to trigger pipelines sequentially or use a CI/CD tool like Jenkins for automation

To regain a deleted branch in git, use the reflog and checkout commands.

• Use 'git reflog' to find the commit hash of the deleted branch

• Run 'git checkout -b ' to recreate the branch

GitHub Actions is a CI/CD tool provided by GitHub for automating workflows and tasks in software development.

• GitHub Actions allows you to automate tasks like building, testing, and deploying code directly from your GitHub repository.

• You can create custom workflows using YAML files to define the actions to be taken based on events like push, pull request, or issue creation.

• GitHub Actions supports a wide range of programming languages and frameworks, making it versatile for dif...read more

Karpenter is a Kubernetes cluster autoscaler that works with EKS to automatically adjust the number of nodes based on workload

• Karpenter monitors the resource usage of pods in the cluster

• It automatically scales the number of nodes up or down based on the workload

• Karpenter integrates with EKS to manage the underlying EC2 instances

I have experience using tools like Prometheus, Grafana, ELK stack, Nagios, and Datadog for monitoring.

• Prometheus

• Grafana

• ELK stack

• Nagios

• Datadog

VPC endpoint is a virtual device within a VPC that allows private connectivity to AWS services without needing an internet gateway or NAT device.

• VPC endpoint enables instances in a VPC to communicate with AWS services privately.

• It provides a secure and scalable way to access AWS services without exposing them to the public internet.

• VPC endpoint URLs typically follow the format 'vpce-xxxxxxxx.service.region.vpce.amazonaws.com'.

Google Cloud Platform (GCP) offers various security features to protect data and resources.

• Identity and Access Management (IAM) for controlling access to resources

• Encryption at rest and in transit to protect data

• Network security with Virtual Private Cloud (VPC) and firewall rules

• Security Key Enforcement for two-factor authentication

• Security Scanner for vulnerability assessment

• Cloud Security Command Center for centralized security management

I have extensive experience with Kubernetes and Openshift in managing containerized applications and orchestrating deployments.

• Managed Kubernetes clusters for deploying and scaling microservices

• Implemented CI/CD pipelines using Jenkins and GitLab for automated deployments on Openshift

• Utilized Helm charts for packaging and deploying applications on Kubernetes

• Configured monitoring and logging tools like Prometheus and ELK stack for observability

Use Terraform to create multiple EC2 instances

• Use Terraform's EC2 instance resource to define the instances

• Specify the number of instances using count parameter

• Use a for_each loop to create multiple instances with unique names and configurations

Playbook for spinning up a Tomcat server

• Install Java on the server

• Download and extract Tomcat

• Configure Tomcat server.xml file

• Start the Tomcat server

• Verify Tomcat is running

Experience with Terraform for creating EKS clusters

• Utilize Terraform modules to define EKS cluster resources

• Leverage Terraform provider for AWS to interact with EKS API

• Use Terraform state management for tracking cluster changes

Release management involves planning, scheduling, and controlling the software release process.

• Planning and coordinating the release of software updates

• Ensuring that the release process is smooth and efficient

• Managing dependencies and version control

• Communicating with stakeholders about release timelines and changes

• Automating release processes to improve efficiency

A Dockerfile is used to create a Docker image by specifying the steps needed to build the image.

• Start with a base image using the FROM keyword

• Use the RUN keyword to execute commands in the image

• Use the COPY keyword to add files from the host machine to the image

• Use the CMD keyword to specify the default command to run when the container starts

Load balancer distributes traffic across multiple servers, while application gateway provides more advanced routing and security features.

• Load balancer operates at layer 4 (TCP/UDP) and distributes traffic based on network-level information like IP address and port numbers

• Application gateway operates at layer 7 (HTTP/HTTPS) and can perform advanced routing based on URL paths, hostnames, and other application-level data

• Load balancer is typically used for distributing traffic t...read more

To add VPC and subnet, go to the VPC dashboard and click on 'Create VPC' button. Then create a subnet within the VPC.

• Go to the VPC dashboard in the AWS console

• Click on the 'Create VPC' button

• Enter the details for the VPC such as name, CIDR block, etc.

• Create a subnet within the VPC by clicking on 'Create Subnet' button

• Enter the details for the subnet such as name, CIDR block, availability zone, etc.

Python code to upload content to s3

• Use boto3 library to interact with AWS S3

• Create a S3 client using boto3

• Use the put_object method to upload content to S3

CMD is used to provide default arguments for an executing container, while ENTRYPOINT is used to specify the command that will run when the container starts.

• CMD is optional and can be overridden during container runtime

• ENTRYPOINT is required and cannot be overridden during container runtime

• CMD can be used to provide default arguments to the ENTRYPOINT command

Challenges faced with Openshift Kubernetes include complexity, resource management, and learning curve.

• Complexity of managing multiple containers and pods

• Resource management to ensure optimal performance and scalability

• Learning curve for understanding Kubernetes concepts and best practices

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

• Start with a base image using the FROM keyword

• Use the RUN keyword to execute commands in the image

• Use the COPY or ADD keyword to add files from the host machine to the image

• Use the CMD keyword to specify the command to run when the container starts

Resolve merge conflicts by understanding changes, communicating with team, using version control tools, and testing changes.

• Understand the changes causing the conflict

• Communicate with team members to discuss conflicting changes

• Use version control tools like Git to resolve conflicts

• Test the changes after resolving conflicts to ensure functionality

CI/CD pipelines are automated processes that build, test, and deploy code changes to production.

• CI/CD stands for Continuous Integration/Continuous Deployment

• CI involves automatically building and testing code changes as they are made

• CD involves automatically deploying code changes to production

• Pipelines are made up of stages, such as build, test, and deploy

• Tools like Jenkins, Travis CI, and CircleCI are commonly used for CI/CD pipelines