1. What is Cloud Computing?
Cloud computing is providing on-demand computing resources, from applications to data centers around the internet. Cloud computing has become the preferred way to deliver enterprise applications and the chosen choice for companies to extend their infrastructure or introduce new technologies
2. What are benefits of Cloud Computing?
Elastic resources: Scale up or down quickly and easily to meet a demand.
Self-service: All the required IT resources with self-service access.
Metered service: You only pay for what you use.
3. What is OpenShift?
OpenShift is the RedHat Cloud Development Platform (PaaS) service. Its flagship product is the on-premises OpenShift Container Platform as a service built around Docker containers orchestrated and controlled by Kubernetes on a Red Hat Enterprise Linux base.Free and open source cloud-based platforms allow developers to build, test and run their applications and deploy them to the cloud.
4. What are pods in Openshift?
The real or virtual equivalents of a machine instance with a container are known as a pod. Each of the pods has its own internal IP address hence is the real owner of its entire space. Containers which are within the same pod can actually share their local storage and networking space. Pods are treated as an immutable instance and any change cannot be made to a pod definition while it is in the running mode.
5. What is a gear in Openshift?
In the terms of Openshift isolated clusters are called as Gears. Gears perform the functioning of the application. Instead of a software piece application is basically performed by gears. Another major term is a cartridge which is basically a construct made up from the reusable gears.
6. What is an OpenShift node?
A node provides the runtime environments for containers. Each node in a Kubernetes cluster has the required services to be managed by the master. Nodes also have the required services to run pods, including Docker, a kubelet, and a service proxy. Administrators can manage nodes in an OpenShift instance using the CLI.
7. Do you know the most important features of Openshift?
There are a lot of features offered by OpenShift. Here are a few main features :
- Software Defined Network
- Persistent Storage.
- Container Native Storage (CNS / SDS).
- Log Aggregation and Analysis.
- Monitoring | Telemetry.
- Capacity Management
- Egress Routing for Enterprise integration. Router Sharding.
- Full Stack Support.
- Automatic Application Scaling
- Rich Command-line Toolset
- Source Code Version Management
- System Certifications and Patching.
- Multi Environment Support
- Software Defined Network
- Multiple database and Language Support
- Remote Debugging of Applications
- Support for remote SSH login to application.
- Rest API Support
- Self-service on Demand Application Stack
- Remote Debugging of Applications
- Built-in Database Services
- Continuous Integration and Release Management
- Extensible Cartridge System
- IDE Integration
8. What Is Openshift Online?
OpenShift online is an OpenShift community service that allows one to create, deploy and scale containerized applications on the public cloud quickly.It is the development and hosting platform of Red Hat’s public cloud platform, which enables automated provisioning, management and application scaling to help developers concentrate on the development of framework logic.
9. What is bootstrap node in OpenShift?
Node Bootstrapping. Starting in OpenShift Container Platform 3.10, a node’s configuration is bootstrapped from the master, which means nodes pull their pre-defined configuration and client and server certificates from the master. When node services are started, the node checks if the /etc/origin/node/node.
10. Is OpenShift free to use?
OpenShift.io is a free, end-to-end, cloud-native development experience.
11. What is OpenShift in Linux?
OpenShift is a family of containerization software products developed by Red Hat. Its flagship product is the OpenShift Container Platform an on-premises platform as a service built around Docker containers orchestrated and managed by Kubernetes on a foundation of Red Hat Enterprise Linux.
12. Why do we need OpenShift?
OpenShift accelerates application development by including the tools that companies need to be agile and efficient. With OpenShift, your business can deploy applications quickly, become less siloed, be more interactive, and increase collaboration.
13. Is OpenShift a cloud?
OpenShift is a cloud development Platform as a Service (PaaS) developed by Red Hat. It is an open source development platform, which enables the developers to develop and deploy their applications on cloud infrastructure.
14. What can you run on OpenShift?
Red Hat OpenShift includes pre-created quick start application templates that allow you to build and deploy your favorite application languages, frameworks, and databases with one click—Java, Node. js, .NET, Ruby, Python, PHP and more.
15. What is in Openshift Enterprise?
It is again a Red Hat’s service platform which fluently provides all of the developers and its organizations with many features. This includes auto-scaling, security deploying new applications, scalable resources with significant configuration and many more. The Openshift enterprise also supports programming languages and their framework, integrated tools and application lifecycle. As an open source service project, Openshift provides many of the deployment and applications of the web services on the cloud.
16. How would you define automation in Openshift?
Automation in Openshift includes the source code management, application build up, scaling and deploying, management and many more.
17. What Is Pod?
Pods are the rough equivalent of a machine instance physical or virtual to a container. OpenShift leverages the Kubernetes concept of a pod , which is one or more containers deployed together on one host, and the smallest compute unit that can be defined, deployed, and managed. The Kubernetes scheduling unit is the Pod, which is a grouping of containers sharing a virtual network device, internal IP address, TCP/UDP ports, and persistent storage. A Pod can be anything from a complete enterprise application, including each of its layers as a distinct container, to a single microservice inside a single container. Kubernetes manages replicas to scale pods. A replica is a set of pods sharing the same definition. OpenShift treats pods as largely immutable; changes cannot be made to a pod definition while it is running.
18. What is OpenShift deployment?
Deployment in OpenShift is a replication controller based on a user-defined template called a deployment configuration. Deployments are manually created, or in response to triggered events. The deployment system provides the following:
- A deployment configuration, which is a template for deployments.
- Triggers that drive automated deployments in response to events.
- User-customizable strategies to transition from the previous deployment to the new deployment.
- Rollbacks to a previous deployment.
- Manual replication scaling.
19. What Are Deployment Strategies?
A deployment strategy is a way to change an application or to update it. The goal is to make the transition in a way that the consumer barely notices the changes, without downtime. Using a blue-green deployment is the commonest technique. The new version (the blue version) is being built for testing and evaluation, while the users are still using the stable version (the green). The users are moved to the blue version when it’s available. You can go back to the Green version if a problem occurs.
20. What Is Rolling Strategy?
A rolling rollout gradually replaces instances of an application’s prior version with instances of the application’s current version. A rolling deployment usually waits for new pods to get ready through a readiness test until the old modules are scaled down. The rolling deployment can be halted if a serious problem occurs.
21. What Is Canary Deployments?
All rolling deployments in OpenShift Origin are canary deployments; it checks a new version before replacing all the old instances. Unless the readiness test never works, then the canary instance and deployment will be disabled.
22. What Is Routes In Openshift?
In OpenShift Routes is a way to externalize the services by providing externally reachable hostname. In OpenShift routes are created using routers developed by admin.
23. What is difference between Docker and OpenShift?
The key difference is that Docker is focused only on the runtime container as a project, while OpenShift (as a system) contains both the runtime container and the REST API, coordination, and web interfaces for the deployment and management of individual containers.
OpenShift is more a container orchestration abstraction layer. OpenShift uses Kubernetes internally for orchestration of containers. For container orchestration, While Docker has docker swarm for container orchestration.
24. What Is Deployment Pod Resources?
A deployment is completed by a pod that consumes resources memory and CPU on a node. By default, pods consume unbounded node resources. However, if a project specifies default container limits, then pods consume resources up to those limits. Another way to limit resource use is to specify resource limits as part of the deployment strategy.
25. Define Authentication In Openshift?
In OpenShift master has inbuilt OAuth server which generates tokens that can be used for API authentication.
26. What Is Haproxy On Openshift?
On OpenShift, if your application is scalable, HAProxy sits in front of it and accepts all incoming connections. It parses the HTTP protocol and decides which application instance the connection should be routed to. This is important as it allows the user to have sticky sessions.
27. What Is Downward Api In Openshift?
The Downward API is a mechanism whereby pods can retrieve their metadata without having to call into the Kubernetes API.The following metadata can be retrieved and used to configure the running pods:
- Labels
- Annotations
- Pod name, namespace, and IP address
- Pod CPU/memory request and limit information
Certain information can be mounted into the pod as an environment variable, whereas other information can be accessed as files within a volume.
28. What Is Openshift Cli?
OpenShift CLI is used for managing OpenShift applications from the command line. OpenShift CLI has the capability to manage end-to-end application life cycle. In general, we would be using OC which is an OpenShift client to communicate with OpenShift. OpenShift CLI is capable of performing all basic and advance configuration, management, addition, and deployment of applications.
29. Why Use Docker And Kubernetes In Openshift?
Docker helps to create lightweight liner based container while Kubernetes helps in orchestrating and managing containers. OpenShift is built on top of Docker and Kubernetes. All the containers are built on top of Docker cluster, which is basically Kubernetes service on top of Linux machines, using Kubernetes orchestrations feature. In this process, we build Kubernetes master which controls all the nodes and deploys the containers to all the nodes. The main function of Kubernetes is to control OpenShift cluster and deployment flow using a different kind of configuration file. As in Kubernetes, we use kubctl in the same way we use OC command line utility to build and deploy containers on cluster nodes.
30. Explain Openshift Security?
OpenShift security is mainly a combination of two components that mainly handles security constraints.
Security Context Constraints (SCC): It is basically used for pod restriction, which means it defines the limitations for a pod, as in what actions it can perform and what all things it can access in the cluster.
Service Account: Service accounts are basically used to control access to OpenShift master API, which gets called when a command or a request is fired from any of the master or node machine.
31. What Are Labels In Open‐shift?
In OpenShift, Labels are identifying metadata consisting of key/value pairs attached to resources. Labels are used to add identifying attributes to objects that are relevant to users and can be used to reflect architectural or organizational concepts. Labels can be used in conjunction with label selectors to uniquely identify individual resources or groups of resources.
Examples:
- Release
- Environment
- Relationship
- DMZBased
- Tier
- Node types
- User type
32. What Is Openshift Pipeline?
OpenShift Pipelines give you control over building, deploying, and promoting your applications on OpenShift. Using a combination of the Jenkins Pipeline Build Strategy, Jenkins files, and the OpenShift Domain Specific Language (DSL) provided by the OpenShift Jenkins Client Plug-in, you can create advanced build, test, deploy, and promote pipelines for any scenario.
33. What are the advantages of Openshift?
Following are the advantages of Openshift:
- It gives a container the executive’s stage to your complex IT organization.
- Kubernetes is the business driving open-source container organization system, and the Red Hat OpenShift Container Platform is the primary endeavor conveyance of Kubernetes.
- Empower your improvement group to zero in on planning and testing applications instead of investing excessive time in deploying and maintaining the containers.
- It incorporates containerization for automatic-provisioning, continuous integration, multitenancy, self-service, and automatic application scaling for developers.
34. Define routes and services in Openshift?
A pod comprises services and containers; subsequently, service in Openshift is a get together of coherent pods. The service is considered fundamentally as a REST object in Openshift. Routes are given in Openshift to externalize and investigate the services needed to reach the hostname remotely. It is achieved by utilizing the routes created by the admin commands.
35. Enlist a few build strategies that are used in Openshift?
Following are the major build strategies used in Openshift:
- Custom Strategy
- Source to image Strategy
- Docker Strategy
- Pipeline Strategy
36. Differentiate Openstack and Openshift?
The two of them are the original inception from open-source projects, and they similarly give Cloud Computing essentials. The significant distinction between them is that OpenStack provides a framework for administration or the structure ‘IaaS.’ It additionally provides object storage and blocks storage to the bootable virtual machine. Then again, Openshift performs unexpectedly.
37. Explain about Volume Security?
Volume security implies making sure about the PV and PVC of projects in the OpenShift bunch. There are predominantly four segments to control admittance to volumes in OpenShift.
Supplemental Groups
fsgroup run as user
seLinuxOptions
38. What is the purpose of OpenShift?
OpenShift is a cloud development Platform as a Service (PaaS) developed by Red Hat. It is an open source development platform, which enables the developers to develop and deploy their applications on cloud infrastructure. It is very helpful in developing cloud-enabled services.
39. What is image in OpenShift?
An image stream comprises any number of Docker-formatted container images identified by tags. It presents a single virtual view of related images, similar to an image repository, and may contain images from any of the following: Its own image repository in OpenShift Enterprise’s integrated registry.
40. What is meant by features toggles?
Feature toggles are where the two forms of your element are remembered for a similar codebase. However, they are encircled by the rationale to execute, depending on external factors, such as a property estimation or information base switch. This is a helpful procedure to isolate the deployment from multiple server groups, legacy monoliths, setups, and single server groups.
