Cloud Foundry Interview Questions with Explanation

1) What is the Cloud Foundry?

A) Cloud Foundry is an open-source cloud computing platform originally developed in-house at VMware. It is now owned by Pivotal Software, which is a joint venture made up of VMware, EMC, and General Electric.

cloud foundry interview questions

2) Why do we need Cloud Foundry?

A) Cloud Foundry (CF) has become the industry standard. It is an open source platform that you can deploy to run your apps on your own computing infrastructure, or deploy on an IaaS like AWS, vSphere, or OpenStack. You can also use a PaaS deployed by a commercial Cloud Foundry cloud provider.

3) What is a Buildpack?

A) Buildpack is a core link in the chain of the Cloud Foundry deployment process. It automates detection of an application framework, application compilation and running. Being a happy user of Cloud Foundry for a long time, I haven’t had any troubles while using the official build packs for Ruby, Java, and Python projects.

4) What is the use of Cloud Foundry?

A) Cloud Foundry is an open source cloud platform as a service (PaaS) on which developers can build, deploy, run and scale applications.

5) Is Cloud Foundry a PAAS?

A) Cloud Foundry is an open source, multi-cloud application platform as a service (PaaS) governed by the Cloud Foundry Foundation, a 501(c)(6) organization.

6) What is Cloud Foundry’s container-based architecture?

A) Cloud Foundry’s container-based architecture runs apps in any programming language over a variety of cloud service providers. This multi-cloud environment allows developers to leverage the cloud platform that suits specific app workloads and move those workloads as necessary within minutes with no changes to the app.

7) What is Open Service Broker API?

A) Applications deployed to Cloud Foundry access external resources via a Open Service Broker API.

8) What are services in Cloud Foundry?

A) In a Cloud Foundry platform, all external dependencies such as databases, messaging systems, files systems and so on are considered Services.

Pivotal Cloud Foundry Interview Questions
9) What is Pivotal Cloud Foundry (PCF)?

A) A commercial version called Pivotal Cloud Foundry (PCF) is available from Pivotal. It provides extra tools for installation and administration not included in the open software product.

10) What is BOSH in Cloud Foundry?

A) BOSH creates and deploys virtual machines (VMs) on top of a physical computing infrastructure, and deploys and runs Cloud Foundry on top of this cloud.

Cloud Foundry Interview Questions # 11) What is the Cloud Controller?

A) The Cloud Foundry Cloud Controller runs the apps and other processes on the cloud’s VMs, balancing demand and managing app lifecycles.

Cloud Foundry Interview Questions # 12) What is the router?

A) The router routes incoming traffic from the world to the VMs that are running the apps that the traffic demands, usually working with a customer-provided load balancer.

Cloud Foundry Interview Questions # 13) What is User Authentication and Authorization in CF?

A) Cloud Foundry manages user accounts through two User Authentication and Authorization (UAA) servers, which support access control as OAuth2 services and can store user information internally, or connect to external user stores through LDAP or SAML.

Cloud Foundry Interview Questions # 14) Where Cloud Foundry Stores Resources?

A) Cloud Foundry uses the git system on GitHub to version-control source code, buildpacks, documentation, and other resources.

Cloud Foundry Interview Questions # 15) What is OAuth2 Server (UAA) and Login Server?

A) The OAuth2 server (the UAA) and Login Server work together to provide identity management.

Cloud Foundry Interview Questions # 16) What are the components of Cloud Foundry?

A) Cloud Foundry components include a self-service application execution engine, an automation engine for application deployment and lifecycle management, and a scriptable command line interface (CLI), as well as integration with development tools to ease deployment processes.

Cloud Foundry has an open architecture that includes a buildpack mechanism for adding frameworks, an application services interface, and a cloud provider interface.

Cloud Foundry Interview Questions # 17) List out the components of Cloud Foundry?

A) The list of Cloud Foundry components:

Cloud Foundry Components

Routing – Router
Authentication – OAuth2 Server (UAA) and Login Server
App Lifecycle – Cloud Controller and Diego Brain, nsync, BBS, and Cell Reps
App Storage and Execution – Blobstore, Diego Cell
Services – Service Brokers
Messaging – Consul and BBS
Metrics and Logging – Loggregator
18) Cloud Controller maintains which records?

A) The Cloud Controller also maintain records of orgs, spaces, user roles, services, and more.

Cloud Foundry Interview Questions # 19) What are nsync, BBS, and Cell Reps?

A) To keep applications available, cloud deployments must constantly monitor their states and reconcile them with their expected states, starting and stopping processes as required.

The nsync, BBS, and Cell Rep components work together along a chain to keep apps running. At one end is the user. At the other end are the instances of applications running on widely-distributed VMs, which may crash or become unavailable.

Pivotal Cloud Foundry Software Engineer Interview Questions
Cloud Foundry Interview Questions # 20) How the nsync, BBS, and Cell Rep components work together?

A) nsync receives a message from the Cloud Controller when the user scales an app. It writes the number of instances into a DesiredLRP structure in the Diego BBS database.

BBS uses its convergence process to monitor the DesiredLRP and ActualLRP values. It launches or kills application instances as appropriate to ensure the ActualLRP count matches the DesiredLRP count.

Cell Rep monitors the containers and provides the ActualLRP value.

Cloud Foundry Interview Questions # 21) What is Blobstore?

A) The blobstore is a repository for large binary files, which Github cannot easily manage because Github is designed for code. The blobstore contains the following:

Application code packages
Buildpacks
Droplets
22) What is Diego Cell?

A) Application instances, application tasks, and staging tasks all run as Garden containers on the Diego Cell VMs. The Diego cell rep component manages the lifecycle of those containers and the processes running in them, reports their status to the Diego BBS, and emits their logs and metrics to Loggregator.

Cloud Foundry Interview Questions # 23) What are Service Brokers?

A) Applications typically depend on services such as databases or third-party SaaS providers. When a developer provisions and binds a service to an application, the service broker for that service is responsible for providing the service instance.

Cloud Foundry Interview Questions # 24) What are Consul and BBS?

A) Cloud Foundry component VMs communicate with each other internally through HTTP and HTTPS protocols, sharing temporary messages and data stored in two locations:

A Consul server stores longer-lived control data, such as component IP addresses and distributed locks that prevent components from duplicating actions.

Diego’s Bulletin Board System (BBS) stores more frequently updated and disposable data such as cell and application status, unallocated work, and heartbeat messages. The BBS stores data in MySQL, using the Go MySQL Driver.

Cloud Foundry Interview Questions # 25) What is Loggregator?

A) The Loggregator (log aggregator) system streams application logs to developers.

Cloud Foundry Interview Questions # 26) What is Metrics Collector?

A) The metrics collector gathers metrics and statistics from the components. Operators can use this information to monitor a Cloud Foundry deployment.

Cloud Foundry Interview Questions # 27) What is Diego in CF?

A) Diego is a self-healing container management system that attempts to keep the correct number of instances running in Diego Cells to avoid network failures and crashes. Diego schedules and runs Tasks and Long-Running Processes (LRP).

Cloud Foundry Interview Questions # 28) What are the components of Diego architecture?

A) Diego architecture consists of below components:

Diego Cell Components
Diego Brain Components
Database VMs
Access VMs
Cloud Controller Bridge Components
Consul
App Lifecycle Binaries
Cloud Foundry Interview Questions # 29) What is Diego Brain?

A) Diego Brain distribute Tasks and LRPs to Diego Cells and corrects discrepancies between Actual and Desired counts to ensure fault-tolerance and long-term consistency.

Cloud Foundry Interview Questions # 30) What is CC-Bridge?

A) The CC-Bridge translate app-specific requests from the Cloud Controller to the BBS.

Advanced Cloud Foundry Interview Questions
31) What are the CC-Bridge components?

A) The CC-Bridge components are:

Stager, CC-Uploader, Nsync Bulker, Nsync Listener, TPS Listener, and TPS Watcher.

32) How Diego Balances App Processes?

A) Diego balances app processes over the virtual machines (VMs) in a Cloud Foundry (CF) installation using the Diego Auction. When new processes need to be allocated to VMs, the Diego Auction determines which ones should run on which machines. The auction algorithm balances the load on VMs and optimizes app availability and resilience.

33) What are the SSH Components in CF?

A) The Cloud Foundry SSH includes the following central components, they are:

An implementation of an SSH proxy server.

A lightweight SSH daemon.

34) What is SSH Daemon?

A) The SSH daemon is a lightweight implementation that is built around the Go SSH library. It supports command execution, interactive shells, local port forwarding, and secure copy. The daemon is self-contained and has no dependencies on the container root file system.

35) What is SSH Proxy Authentication?

A) The SSH proxy hosts the user-accessible SSH endpoint and is responsible for authentication, policy enforcement, and access controls in the context of Cloud Foundry. After a user has successfully authenticated with the proxy, the proxy will attempt to locate the target container and create an SSH session to a daemon running inside the container. After both sessions have been established, the proxy will manage the communication between the user’s SSH client and the container’s SSH Daemon.

36) What is role-based access control (RBAC) system in CF?

A) Cloud Foundry uses a role-based access control (RBAC) system to grant Cloud Foundry users permissions appropriate to their role within an org or a space.

37) What are the security features available in Cloud Foundry?

A) Cloud Foundry implements the following measures to mitigate against security threats:

Minimizes network surface area

Isolates customer applications and data in containers

Encrypts connections

Uses role-based access controls, applying and enforcing roles and permissions to ensure that users can only view and affect the spaces for which they have been granted access

Ensures security of application bits in a multi-tenant environment

Prevents possible denial of service attacks through resource starvation

38) What are Isolation Segments?

A) Isolation segments provide dedicated pools of resources to which apps can be deployed to isolate workloads. Using isolation segments separates app resources as completely as if they were in different Cloud Foundry deployments but avoids redundant management components and unneeded network complexity.

39) Explain about Software Vulnerability Management in CF?

A) Cloud Foundry manages software vulnerability using releases and BOSH stemcells. New Cloud Foundry releases are created with updates to address code issues, while new stemcells are created with patches for the latest security fixes to address any underlying operating system issues.

Pivotal Cloud Foundry Interview Questions For Experienced
40) Can you describe about Container Security in CF?

A) Cloud Foundry (CF) secures the containers that host application instances on Linux.

Container Mechanics provides an overview of container isolation.

Inbound and Outbound Traffic from Cloud Foundry provides an overview of container networking and describes how Cloud Foundry administrators customize container network traffic rules for their deployment.

Container Security describes how Cloud Foundry secures containers by running application instances in unprivileged containers and by hardening them.

41) What measures Cloud Foundry can take for Container Security?

A) Cloud Foundry secures containers through the following measures:

Running application instances in unprivileged containers by default

Hardening containers by limiting functionality and access rights

Only allowing outbound connections to public addresses from application containers. This is the original default. Administrators can change this behavior by configuring ASGs.

42) What is Container-to-Container Networking?

A) The Container-to-Container Networking feature enables app instances to communicate with each other directly. Container-to-Container Networking integrates with Garden-runC in a Diego deployment. The Container-to-Container Networking BOSH release includes several core components, as well as swappable components.

43) What are the components of Container-to-Container Networking?

A) The Container-to-Container Networking BOSH release includes the following core components:

Cloud Foundry Command Line Interface (Cloud Foundry CLI) plugin

Policy Server

Garden External Networker

The Container-to-Container Networking BOSH release includes the following swappable components:

Silk CNI plugin

VXLAN Policy Agent

44) What is Zipkin Tracing?

A) Zipkin is a tracing system that enables app developers to troubleshoot failures or latency issues. Zipkin provides the ability to trace requests and responses across distributed systems.

45) What is a Stack?

A) A stack is a prebuilt root filesystem (rootfs) that supports a specific operating system. For example, Linux-based systems need /usr and /bin directories at their root. The stack works in tandem with a buildpack to support applications running in compartments. Under Diego architecture, cell VMs can support multiple stacks.

46) How do you deploy Cloud Foundry?

A) If installing Cloud Foundry for the first time, deploy with cf-deployment.

If you have an existing Cloud Foundry deployment that uses cf-release, migrate your deployment to cf-deployment.

47) How do you add a Buildpack?

A) To add a buildpack, run the Cloud Foundry create-buildpack BUILDPACK PATH POSITION [–enable|–disable] command.

48) How do you use Docker in Cloud Foundry?

A) By default, apps deployed with the Cloud Foundry push command run in standard Cloud Foundry Linux containers. With Docker support enabled, Cloud Foundry can also deploy and manage apps running in Docker containers.

To deploy apps to Docker, developers run Cloud Foundry push with the –docker-image option and the location of a Docker image to create the containers from.

To enable Docker support on a Cloud Foundry deployment, an operator must do the following:

Enable the diego_docker feature flag.

Configure access to any Docker registries that developers want to use images from.

Cloud Foundry Multiple Choice Questions

As per 12 Factor, each component in the codebase should be an APP.
Choose the correct answer from below given options:
a) False
b) True

Correct answer of the above question is : b) True

What does PCloud Foundry stand for____.
Choose the correct answer from below given options:
a) Private Cloud Foundry
b) Platform Cloud Foundry
c) Pivotal Cloud Foundry

Correct answer of the above question is : c) Pivotal Cloud Foundry

Cloud Foundry Interview Questions Primarily Cloud Foundry is written in _.
Choose the correct answer from below given options:
a) Go
b) All the options
c) Java
d) Ruby

Correct answer of the above question is : b) All the options

Cloud Foundry deploys applications on any computing infrastructure.
Choose the correct answer from below given options:
a) False
b) True

Correct answer of the above question is : b) True

Market place services are _.
Choose the correct answer from below given options:
a) Cloud Foundry Managed
b) User Managed

Correct answer of the above question is : a) Cloud Foundry Managed

Cloud Foundry Interview Questions __ streams application logs to developers.
Choose the correct answer from below given options:
a) Service broker
b) App Log Aggregator
c) Metrics Collector
d) None of the options

Correct answer of the above question is : b) App Log Aggregator

Features of a Cloud Foundry Service are is __.
Choose the correct answer from below given options:
a) External to the application
b) Are bound to an application
c) Shared among many applications
d) All the options
e) Functionality to the application

Correct answer of the above question is : d) All the options

What is the purpose of n option under Cloud Foundry push command?
Choose the correct answer from below given options:
a) To specify the number of instances on which this application should be running
b) To specify the name of the app as it appears in Cloud Foundry
c) To specify the number of memory units of 256M that are needed

Correct answer of the above question is : b) To specify the name of the app as it appears in Cloud Foundry

Command that is used to deploy an application in Cloud Foundry is _____________.
Choose the correct answer from below given options:
a) Cloud Foundry push
b) Cloud Foundry upload
c) Cloud Foundry stage
d) Cloud Foundry start

Correct answer of the above question is : a) Cloud Foundry push

Application deployments are directed by _.
Choose the correct answer from below given options:
a) Cell Reps
b) nsync
c) Cloud Controller
d) BBS

Correct answer of the above question is : c) Cloud Controller

CF_STAGING_TIMEOUT and CF_STARTUP_TIMEOUT commands are used to control stagging and start up.
Choose the correct answer from below given options:
a) False
b) True

Correct answer of the above question is : b) True

RTR section in the log indicates log entries for____.
Choose the correct answer from below given options:
a) Your application instance
b) Cloud Controller
c) Droplet Execution Agent
d) Router

Correct answer of the above question is : d) Router

What is the deployment blueprint for an application?
Choose the correct answer from below given options:
a) Manifest
b) Buildpack
c) Services
d) None of the options
e) Routes

Correct answer of the above question is : a) Manifest

Organization contains _ space.
Choose the correct answer from below given options:
a) Single
b) Not applicable
c) Multiple

Correct answer of the above question is : c) Multiple

__ restricts the availability of resources to an organization.
Choose the correct answer from below given options:
a) Routes
b) Domain
c) Quotas
d) Services

Correct answer of the above question is : c) Quotas

done untill here

What is the command to check the version?
Choose the correct answer from below given options:
a) pc version
b) Cloud Foundry – – version
c) cp – – version

Correct answer of the above question is : b) Cloud Foundry – – version

_____ allows cloud controller to locate instances on separate zones to boost redundancy.
Choose the correct answer from below given options:
a) Availability Zones
b) Cloud Space
c) Cloud Zones
d) Availability Space
e) Organizations
f) Space Zones

Correct answer of the above question is : a) Availability Zones

Which of the following option is used to specify push timeout in seconds?
Choose the correct answer from below given options:
a) -t
b) -i
c) -n
d) -v

Correct answer of the above question is : a) -t

__ is a blob of metadata or a file containing metadata of a group of accompanying files.
Choose the correct answer from below given options:
a) Manifests
b) Apaces
c) Application
d) Buildpacks

Correct answer of the above question is : a) Manifests

Which of the following command lists all the applications within a space?
Choose the correct answer from below given options:
a) Cloud Foundry log < app name>
b) Cloud Foundry apps
c) Cloud Foundry app < app_name>
d) Cloud Foundry events < app-name>

Correct answer of the above question is : b) Cloud Foundry apps

_ allows Cloud Foundry to support multiple language and development environments.
Choose the correct answer from below given options:
a) Buildpacks
b) Domains
c) Organizations
d) Manifests

Correct answer of the above question is : a) Buildpacks

Select the responsibilities of a Service Broker.
Choose the correct answer from below given options:
a) Make create/bind/ unbind/ delete calls to service nodes
SaaS marketplace gateway
b) All the options
c) Advertising service catalog

Correct answer of the above question is : b) All the options

App Direct is __ provider of services.
Choose the correct answer from below given options:
a) Private
b) Commercial
c) Public

Correct answer of the above question is : b) Commercial

Which of the following command is used to deploy an application to Cloud Foundry?
Choose the correct answer from below given options:
a) Cloud Foundry push
b) Cloud Foundry routes
c) Cloud Foundry start
d) Cloud Foundry login

Correct answer of the above question is : a) Cloud Foundry push

Default space for PWS is____.
Choose the correct answer from below given options:
a) production
b) testing
c) development

Correct answer of the above question is : c) development

Services that are selected from the marketplace catalog are known as __.
Choose the correct answer from below given options:
a) All the options
b) User defined services
c) Managed services
d) Custom built services

Correct answer of the above question is : c) Managed services

Command to login to Cloud Foundry is _.
Choose the correct answer from below given options:
a) Cloud Foundry routes
b) Cloud Foundry push
c) Cloud Foundry login
d) Cloud Foundry start

Correct answer of the above question is : c) Cloud Foundry login

done untill here**

The location where the applications are deployed is known as __.
Choose the correct answer from below given options:
a) Manifests
b) Buildpacks
c) Spaces
d) Application

Correct answer of the above question is : c) Spaces

__ is the dependancy of an external appllication.
Choose the correct answer from below given options:
a) Buildpacks
b) Service
c) Organization
d) Manifests

Correct answer of the above question is : b) Service

Cloud Foundry Interview Questions Issue in Cloud Foundry can be _.
Choose the correct answer from below given options:
a) Push issues
b) Runtime issues
c) All the options
d) Deployment issue

Correct answer of the above question is : c) All the options

m option in the push command usage represents _.
Choose the correct answer from below given options:
a) Host name
b) Memory limit
c) Local path to app directory
d) Number of instances

Correct answer of the above question is : b) Memory limit

__ are defined as the unit of deployment in Cloud Foundry.
Choose the correct answer from below given options:
a) Manifests
b) Applications
c) Organizations
d) Buildpacks

Correct answer of the above question is : b) Applications

m option in the push command usage represents _.
Choose the correct answer from below given options:
a) Host name
b) Memory limit
c) Local path to app directory
d) Number of instances

Correct answer of the above question is : b) Memory limit

__ are defined as the unit of deployment in Cloud Foundry.
Choose the correct answer from below given options:
a) Manifests
b) Applications
c) Organizations
d) Buildpacks

Correct answer of the above question is : b) Applications

Which is the commercial product offered by Cloud Foundry?
Choose the correct answer from below given options:
a) Pivotal Web Services
b) Pivotal Web Services – E
c) Pivotal Cloud Foundry

Correct answer of the above question is : c) Pivotal Cloud Foundry

Cloud Foundry Interview Questions With Platform as a Service, your infrastructure management responsibilities are greatly reduced.
Choose the correct answer from below given options:
a) True
b) False

Correct answer of the above question is : a) True

Cloud Foundry is a __ type of distributed services.
Choose the correct answer from below given options:
a) Software as a Service
b) Platform as a service
c) All the options
d) Infrastructure as a Service

Correct answer of the above question is : b) Platform as a service

_ directs incoming traffic to the Cloud Foundry.
Choose the correct answer from below given options:
a) Router
b) Cloud controller
c) OAuth2 server
d) Login Server

Correct answer of the above question is : a) Router

__ stores longer lived control data like component IP addresses and distributed locks.
Choose the correct answer from below given options:
a) Bulletin Board System
b) Consul
c) NATS
d) All the options

Correct answer of the above question is : b) Consul

_ performs start and stop actions of an application locally in the application virtual machine (VM).
Choose the correct answer from below given options:
a) Blobstore
b) Cell Reps
c) Garden
d) Diego Cell

Correct answer of the above question is : d) Diego Cell