Marolix Technology Solutions Devops Engineer Interview Questions and Answers

Security in Terraform involves managing sensitive data, implementing access controls, and using secure communication channels.

• Use Terraform's sensitive data handling features like sensitive variables and sensitive outputs to protect sensitive information.

• Implement access controls using Terraform's built-in features like IAM policies, resource-level permissions, and secure storage backends.

• Use secure communication chann...read more

Helm is a package manager for Kubernetes that simplifies the deployment and management of applications.

• Helm charts are packages of pre-configured Kubernetes resources that can be easily deployed using Helm.

• Helm charts are written in YAML and can include templates for Kubernetes manifests.

• Helm allows for easy versioning, sharing, and management of Kubernetes applications.

• To use Helm, you need to install the Helm client ...read more

Control plane components in Kubernetes manage the cluster and make decisions about the state of the cluster.

• Control Manager: Ensures that the desired state of the cluster matches the actual state.

• Scheduler: Assigns workloads to nodes based on resource availability and constraints.

• API Server: Acts as the front-end for the Kubernetes control plane and is the primary interface for users and other components.

• etcd: Consiste...read more

Implementing zero-downtime deployments in Kubernetes involves using rolling updates and readiness probes.

• Use rolling updates to gradually replace old pods with new ones

• Configure readiness probes to ensure new pods are ready before routing traffic to them

• Utilize tools like Helm for managing releases and versioning

To ensure high availability of the etcd cluster used by Kubernetes, you can implement redundancy, monitoring, and disaster recovery strategies.

• Implement a multi-node etcd cluster to ensure redundancy and fault tolerance.

• Utilize monitoring tools like Prometheus and Grafana to track the health and performance of the etcd cluster.

• Set up regular backups and implement disaster recovery plans to quickly recover from failures...read more

Capacity planning for a Kubernetes cluster involves analyzing resource usage, predicting future needs, and scaling infrastructure accordingly.

• Monitor resource usage of pods and nodes using tools like Prometheus and Grafana

• Analyze historical data to identify trends and patterns in resource consumption

• Estimate future resource requirements based on application growth and workload changes

• Scale the cluster by adding or remo...read more

Yes, I faced challenges while creating the DevOps pipeline.

• One challenge was integrating multiple tools and technologies into the pipeline.

• Another challenge was ensuring smooth communication and collaboration between different teams involved in the pipeline.

• I also faced challenges in automating the testing and deployment processes to achieve continuous integration and continuous delivery.

• Dealing with legacy systems and...read more

Containers in Kubernetes communicate with each other through networking and service discovery mechanisms.

• Containers within the same pod can communicate over localhost.

• Containers in different pods can communicate using Kubernetes services.

• Kubernetes assigns each pod a unique IP address for communication.

• Kubernetes also supports DNS-based service discovery for containers.

Restricting communication between Kubernetes pods can be achieved using network policies.

• Use Network Policies in Kubernetes to define rules for pod-to-pod communication

• Specify which pods are allowed to communicate with each other based on labels

• Deny all traffic by default and only allow specific traffic as needed

• Example: Define a network policy to allow communication only between pods with label 'app=frontend' and 'app

A virtual private cloud (VPC) or Vnet is a private network in the cloud that allows you to isolate resources and control network traffic.

• VPC/Vnet provides a secure and isolated environment for resources in the cloud.

• It allows you to define your own IP address range, subnets, route tables, and network gateways.

• VPC/Vnet helps in creating a secure connection between on-premises data centers and cloud resources.

• It is used ...read more

Ansible is a popular automation tool used in DevOps for configuration management, application deployment, and orchestration.

• Ansible is agentless, meaning it does not require any software to be installed on the nodes being managed.

• It uses YAML syntax for writing playbooks, which are used to define automation tasks.

• Ansible can be used for tasks such as provisioning servers, deploying applications, and managing configurat...read more

Client based development is a software development approach where the client's needs and feedback are prioritized throughout the development process.

• Focus on meeting client requirements and expectations

• Regular communication and feedback from the client

• Iterative development cycles based on client input

• Client involvement in decision-making processes

• Examples: Agile development, customer-centric design

Resilience testing is a type of testing that evaluates a system's ability to recover from failures and continue functioning.

• Resilience testing involves intentionally introducing failures or disruptions to a system to see how it responds.

• The goal of resilience testing is to identify weaknesses in the system's design or implementation that could lead to downtime or data loss.

• Examples of resilience testing include simulat...read more

DevOps KPI are key performance indicators used to measure the success of DevOps practices in an organization.

• DevOps KPIs should align with business goals and objectives.

• Examples of DevOps KPIs include deployment frequency, lead time for changes, mean time to recover, and change failure rate.

• Monitoring KPIs helps in identifying areas for improvement and optimizing DevOps processes.

Various branching strategies in version control systems help manage code changes effectively.

• Mainline/Branch by Release: Each release has its own branch for bug fixes and maintenance.

• Feature Branching: Each new feature is developed in a separate branch and merged back to main branch after completion.

• Gitflow Workflow: Uses main, develop, feature, release, and hotfix branches for a structured workflow.

• Trunk-Based Develop...read more

Feature branching and task branching are strategies used in version control systems to manage development tasks.

• Feature branching involves creating a separate branch for each new feature being developed, allowing for isolation and independent development.

• Task branching is similar to feature branching but is used for smaller tasks or bug fixes.

• Both feature branching and task branching help in organizing and managing cod...read more

Continuous delivery focuses on automating the software delivery process up to production, while continuous deployment automatically deploys every change to production.

• Continuous delivery involves automating the software delivery process up to production, ensuring that code is always in a deployable state.

• Continuous deployment goes a step further by automatically deploying every change that passes automated tests to pro...read more

DevOps methodology consists of various phases including plan, code, build, test, release, deploy, operate, and monitor.

• Plan: Define goals, set priorities, and create a roadmap.

• Code: Develop and review code changes.

• Build: Compile the code and create executable files.

• Test: Verify code changes through automated testing.

• Release: Deploy changes to production environment.

• Deploy: Automate deployment process to various environ...read more

Blue green deployment pattern is a software release strategy that reduces downtime and risk by running two identical production environments.

• In blue green deployment, one environment (blue) is currently live and serving production traffic, while the other environment (green) is idle.

• Once the new version of the software is deployed to the green environment and tested thoroughly, traffic is switched from the blue to the ...read more

Key elements in continuous testing tools include automation, integration with CI/CD pipelines, reporting and analytics, scalability, and support for various testing types.

• Automation of test cases to ensure quick feedback on code changes

• Integration with CI/CD pipelines for seamless testing in the software delivery process

• Reporting and analytics capabilities to track test results and identify issues

• Scalability to handle ...read more

Centralized VCS stores all versions of files in a central server, while distributed VCS allows each user to have a full copy of the repository.

• Centralized VCS has a single point of failure, while distributed VCS is more resilient.

• In centralized VCS, users need constant connection to the central server, while distributed VCS allows offline work.

• Examples of centralized VCS include SVN and CVS, while Git is a popular dist

Setting up a VPC in Azure involves creating a virtual network, subnets, and configuring security groups.

• Create a virtual network in the Azure portal

• Define subnets within the virtual network

• Configure network security groups to control inbound and outbound traffic

• Establish peering connections with other VPCs if needed

IAC stands for Infrastructure as Code, which involves managing and provisioning infrastructure through code. Configuration management involves managing and maintaining the state of systems.

• IAC allows for automating the process of setting up and managing infrastructure using code

• Configuration management ensures that the desired state of systems is maintained consistently

• Tools like Terraform, Ansible, and Puppet are comm...read more

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 (e.g. FROM ubuntu:latest)

• Install dependencies and set up environment (e.g. RUN apt-get update && apt-get install -y python3)

• Copy application code into the image (e.g. COPY . /app)

• Set the default command to run when the container starts (e.g. CMD ["python3", "app.py"])

• Build th...read more

Clusters creation involves setting up multiple servers to work together, while handling practical bugs requires troubleshooting and fixing issues in the cluster.

• Clusters creation involves setting up multiple servers to work together to distribute workload and increase reliability.

• Tools like Kubernetes or Docker Swarm can be used to create and manage clusters efficiently.

• Practical bugs in clusters can include network is...read more

I have 3 years of experience working with Ansible in automating infrastructure and configuration management.

• Implemented Ansible playbooks to automate deployment of applications across multiple servers

• Utilized Ansible roles to standardize configurations and ensure consistency

• Integrated Ansible with CI/CD pipelines for continuous deployment

• Troubleshooted and resolved issues related to Ansible scripts and configurations