Redhat Openshift Q & A

Red Hat Openshift Interview Questions

1. Can you describe the key features of OpenShift 4.10,4.12
2. How do you upgrade an OpenShift 4.x cluster? What are the steps and considerations?
3. What are the differences between OpenShift 3.x and 4.x?
4. Describe a recent issue you faced while configuring OpenShift and how you resolved it.
5. How do you configure persistent storage in OpenShift?
6. What steps do you follow to troubleshoot a failing OpenShift pod?
7. What is an Operator in OpenShift, and why is it important?
8. How do you install, manage, and troubleshoot an Operator in OpenShift?
9. Can you give an example of a situation where you had to troubleshoot an Operator issue?
10. How do you integrate OpenShift with VMware vSphere?
11. What are the benefits of running OpenShift on VMware infrastructure?
12. Describe a scenario where you had to troubleshoot a VM issue that affected OpenShift.

13. How do you optimize RedHat Enterprise Linux for running OpenShift?
14. What are the key differences between RHEL and CoreOS in the context of OpenShift?
15. How do you perform system updates and patching on CoreOS nodes?
16. Can you describe the process of building and deploying a Docker image?
17. How do you secure a Docker registry?
18. What are the common issues you face with Docker images, and how do you troubleshoot them?
19. How do you set up and manage a Docker registry using Quay?
20. What are Persistent Volumes (PVs) and Persistent Volume Claims (PVCs) in OpenShift?
21. How do you handle storage issues in OpenShift?Fluentd, Prometheus log metrics
22. How do you configure logging in OpenShift using the EFK stack?
23. What are the steps to set up Prometheus for monitoring an OpenShift cluster?
24. Can you explain how Fluentd works and how you use it in OpenShift?

25. How do you expose a service outside the OpenShift cluster using routes?
26. What are the different types of services available in OpenShift, and when do you use each?
27. How do you manage and secure OpenShift APIs?
28. Describe the process of deploying a microservices application on OpenShift.
29. What are the best practices for deploying containerized applications in OpenShift?
30. How do you handle service discovery and load balancing for microservices in OpenShift?
31. What is SDN, and how is it implemented in OpenShift?
32. How do you configure and manage network policies in OpenShift?
33. Can you explain how HAproxy is used in OpenShift for load balancing?
34. Can you provide an example of a script you wrote to automate a task in OpenShift?
35. How do you use Ansible for automating OpenShift configurations?
36. What are some common use cases for Python in managing OpenShift?

37. How do you set up a multi-node OpenShift cluster for high availability?
38. What tools and methods do you use for monitoring and performance testing in OpenShift?
39. Describe a situation where you had to troubleshoot a multi-node cluster issue.
40. How do you integrate Zabbix with OpenShift for monitoring?
41. What are the key metrics you monitor in Grafana for an OpenShift cluster?
42. How do you configure alerts in Prometheus for OpenShift?
43. Describe a CI/CD pipeline you implemented for OpenShift using Jenkins.
44. How do you use ArgoCD for GitOps in OpenShift?
45. What are the benefits of using GitOps for managing OpenShift deployments?
46. How do you approach creating high-level and low-level design documents for OpenShift projects?
47. Can you provide an example of a technical document you wrote for an OpenShift deployment?
48. How do you assist team members with technical issues related to OpenShift?

49. Can you describe a complex technical issue you faced in OpenShift and how you resolved it?
50. How do you approach diagnosing and resolving performance issues in OpenShift?
51. What tools and techniques do you use for root cause analysis in OpenShift?

52. Explain Openshift architecture
53. Prerequisite for installing Openshift
54. How do you configure networking in Openshift
55. Have you faced any challenges
56. Walk me through steps you have taken to install openshift on bare metal
57. Can you automate the installation . If yes ,how
58. Have you configured high availability for openshift control plane
59. Have you faced challenges, give an example relating to your environment
60. If the Openshift installation fail , detail the troubleshooting steps
61. How the tasks are being assigned to you – through mail or ticketing process

 

Few Questions and Answers

Key tools and technologies

Red hat Openshift
• Monitoring: Prometheus, Grafana
• Logging: Elasticsearch, Kibana,Kafka, Fluentd
• CI/CD: Jenkins, ArgoCD, GitOps
• Automation: Ansible, Python
• Container Management: Docker
• Network Management: SDN, HAproxy, firewalls

 

Day to day Responsibilities – Red Hat Openshift Admin

1. OpenShift Cluster Management
– Regularly check the health and performance of the OpenShift cluster using monitoring tools like Prometheus
and Grafana.
– Ensure the OpenShift cluster is configured correctly, including managing nodes, network configurations, and
storage.
2. Configuration and Implementation
– Perform installations, upgrades, and patching of the OpenShift platform to ensure it is up-to-date and secure.
– Set up and configure various OpenShift components like Operators, services, routes, and Persistent Volumes
(PVs).
3. Troubleshooting and Support
– Troubleshoot and resolve issues related to OpenShift infrastructure, applications, and integrations. This
includes debugging failing pods, network issues, and performance bottlenecks.
– Provide support to developers and other users of the OpenShift platform, assisting with deployment issues and
performance tuning.

4. Operator Lifecycle Management
– Manage the lifecycle of OpenShift Operators, including installation, upgrades, and troubleshooting any issues
that arise.
– Ensure that Operators are running efficiently and effectively within the cluster.
5. Integration with Vmware
– Manage the integration of OpenShift with VMware technologies such as vCenter and vSphere, ensuring
smooth operation of virtualized infrastructure.
– Monitor and maintain VMs that support the OpenShift environment.
6. Linux and CoreOS Management
– Perform administrative tasks on RedHat Enterprise Linux and CoreOS nodes that form the OpenShift cluster.
– Apply security patches and updates to maintain the stability and security of the operating systems.
7. Docker and Container Management
– Manage Docker image registries like Quay or Docker hub ensuring images are stored securely and efficiently.
– Build Docker images and deploy them to the OpenShift cluster, managing the full lifecycle of container
images

8. Storage Management
– Configure and manage Persistent Volume (PV) and Persistent Volume Claim (PVC) storage solutions to
ensure applications have reliable storage.
– Keep track of storage usage and performance, addressing any issues related to storage capacity or
performance.
9. Logging and Metrics
– Implement and manage logging solutions using Elasticsearch, Kibana, Kafka, and Fluentd
– Use Prometheus to monitor log metrics, setting up alerts for critical events.
10. Network and Security Management
– Configure and manage Software Defined Networking (SDN) in OpenShift, including network policies, ports,
firewalls, and load balancers like HAproxy.
11. Automation and Scripting
– Use automation tools and scripting languages like Python, Ansible to automate routine tasks and
configurations.

12. CI/CD Management
– Set up and manage CI/CD pipelines using tools like Jenkins, ArgoCD, and GitOps to automate the
deployment of applications.
13. Integration with Git:
– Manage integrations with Git repositories for source code management and automated builds

 

What is OpenShift, and how does it differ from Kubernetes?

– OpenShift is a Kubernetes-based container platform developed by Red Hat. It adds developer and operational tools on top of Kubernetes, making it more accessible for enterprises.

 

Explain the difference between a Pod and a Deployment in OpenShift.

– A Pod is the smallest deployable unit in Kubernetes and OpenShift, while a Deployment is a higher-level abstraction that manages the desired state of Pods. Deployments ensure that a specified number of Pod replicas are running at all times.

 

What is the purpose of the OpenShift Origin project?

– OpenShift Origin is the open-source community project that serves as the upstream for Red Hat OpenShift. It allows users to test and contribute to OpenShift’s development.

 

How does OpenShift handle container image security?

– OpenShift employs Image Streams and Source-to-Image (S2I) to build, manage, and deploy container images securely. It uses content trust and signature verification to ensure image security.

 

Explain the role of a Service in OpenShift.

– A Service in OpenShift is responsible for exposing a set of Pods as a network service. It provides a stable endpoint to access the Pods, even if they are replaced or scaled.

 

What is the purpose of a Route in OpenShift?

– A Route in OpenShift is used to expose services to external clients, such as web applications, by creating a hostname and a path that maps to a service.

 

How do you scale an application in OpenShift?

– You can scale an application in OpenShift by using the `oc scale` command or by updating the Deployment configuration with the desired replica count.

 

Explain the concept of a Namespace in OpenShift.

– A Namespace in OpenShift is a virtual cluster that provides a way to divide cluster resources between multiple users or projects. It isolates resources to prevent interference between different projects.

 

What are the main components of an OpenShift cluster?

– An OpenShift cluster comprises the Master Control Plane, which includes the API server, controller manager, and etcd, and the Node Machines, which run the container workloads.

 

How does OpenShift handle application health monitoring and scaling based on metrics?

– OpenShift utilizes Horizontal Pod Autoscalers (HPA) to automatically adjust the number of Pod replicas based on CPU or custom metrics. It also provides integration with Prometheus for monitoring and alerting.

 

What is the difference between a Persistent Volume (PV) and a Persistent Volume Claim (PVC) in OpenShift?

– A Persistent Volume (PV) is a storage resource in the cluster, while a Persistent Volume Claim (PVC) is a request for storage by a user. A PVC binds to a PV to provide storage to a Pod.

 

How can you upgrade OpenShift to a newer version?

– You can upgrade OpenShift by using the `oc` command-line tool or the web console to create a new cluster with the desired version and migrate applications and data from the old cluster to the new one.

 

Explain the concept of Operators in OpenShift.

– Operators are a method of packaging, deploying, and managing applications on OpenShift. They encapsulate operational knowledge, making it easier to manage complex applications.

 

What are Custom Resource Definitions (CRDs) in OpenShift, and why are they important?

– CRDs are extensions to the Kubernetes API that allow you to define custom resources. They are used to define and manage custom resources, such as those used by Operators.

 

How does OpenShift handle security and access control?

– OpenShift uses Role-Based Access Control (RBAC) to define and manage access to resources. It also provides security contexts, pod security policies, and network policies to enhance security.