35+ Most Popularly Asked DevOPs Interview Questions & Answers

Last updated on 04th Jun 2020, Blog, Interview Questions

DevOps is a set of practices, principles, and cultural philosophies that aims to improve collaboration and communication between development (Dev) and operations (Ops) teams in software development and IT operations. Continuous integration and delivery (CI/CD), process automation, and shared accountability for the full software development lifecycle are all stressed in this statement.

1. What is Devops?

Ans:

DevOps is a set of practices, principles, and cultural philosophies that aim to improve collaboration and communication between software development (Dev) and IT operations (Ops) teams.

2. How does DevOps different from agile methodology?

Ans:

DevOps is the culture that allows the development and operations team to work together. This results in a continuous development, testing, integration, deployment, and monitoring of software throughout lifecycle.

Agile is a software development process that emphasizes iterative, incremental, small-batch, and quick software releases, as well as user feedback. It handles the disconnects and disputes between clients and developers.

3. Mention some of the most popular DevOps tools?

Ans:

The most popular DevOps tools are :

• Selenium
• Puppet
• Chef
• Git
• Jenkins
• Ansible
• Docker

4. Define different phases in DevOps?

Ans:

Plan: Getting rough picture of the development process is always good idea.

Code: The application is coded as per end-user requirements.

Build: Build application by integrating different codes formed in the previous steps.

Test: This is most crucial step of the application development. Test application and rebuild, if necessary.

Integrate: The Multiple codes from various programmers are integrated into one.

Operate: An Operations are performed on code if required.

Monitor: Application performance is be monitored.

5. What does core benefits of DevOps.

Ans:

• Continuous software delivery
• Less complex problems to be manage
• Early detection and faster correction of defects
• Faster delivery of features
• Stable operating environments
• Improved communication and collaboration between the teams

6. How will you approach the project that needs to implement DevOps?

Ans:

• Assess current processes and set clear goals.
• Foster collaboration through culture and training.
• Select and integrate DevOps tools.
• Emphasize automation, CI/CD, and monitoring.
• Iterate for continuous improvement.

7. Explain role of configuration management in DevOps?

Ans:

Configuration management plays a crucial role in DevOps by ensuring the consistency, reliability, and efficiency of software and infrastructure configurations. It achieves this by enforcing consistency across different environments, allowing for version control of configurations, and automating infrastructure provisioning through Infrastructure as Code (IaC).

8. Explain the state stalking is in Nagios.

Ans:

• In Nagios, state stalking is used for logging reasons.
• Any modifications it notices in the output of the check results will be recorded.
• This facilitates the study of log files.

9. How does continuous monitoring help you maintain entire architecture system?

Ans:

Continuous monitoring in DevOps is the process of finding, confirming, and reporting any errors or risks throughout the system’s whole infrastructure. This ensures that all the services, applications, and resources are running on a servers properly and monitors a status of servers and finds if applications are working correctly or not.

10. Describe the role of AWS in DevOps?

Ans:

AWS has following role in a DevOps:

• Automation: AWS lets can automate a tasks and processes, giving more time to innovate.
• Secure: Using the AWS Identity and Access Management (IAM), can set user permissions and policies.
• Large partner ecosystem: AWS supports the large ecosystem of partners that be integrate with and extend AWS services.

11. Mention three important DevOps KPIs.

Ans:

Meantime to failure recovery: This is average time taken to recover from failure.

Deployment frequency: How frequently a deployment takes place.

Percentage of unsuccessful deployments: The quantity of unsuccessful deployments.

12. What does “Infrastructure as Code” (IaC) mean in terms of configuration management?

Ans:

Infrastructure as Code (IaC) in configuration management means treating infrastructure setup and configuration as code. It involves using code to define, version, and automate the provisioning and setting up of infrastructure resources, like servers and networks. This approach improves consistency, reproducibility, and scalability while reducing manual errors in managing infrastructure.

 13. How can Infrastructure as Code (IaC) benefit IoT deployments?

Ans:

IaC plays a crucial role in IoT deployments by bringing automation and consistency to the management of infrastructure components. Here are some ways IaC benefits IoT:

• Scalability
• Consistency
• Version Control
• Speed and Efficiency

14. Why does Nagios said to be object-oriented?

Ans:

Using object configuration format, can create the object definitions that inherit the properties from the other object definitions. Hence, Nagios is known as a object-oriented.

15. Explain the state stalking is in Nagios.

Ans:

State stalking is used for a logging purposes in Nagios. When stalking is an enabled for particular host or service, Nagios will watch that host or a service very carefully. It will log any changes it sees in an output of check results.This helps in analysis of log files.

16. Explain anti-patterns of DevOps?

Ans:

Patterns are general practices that are usually followed by an organizations. An anti-pattern is formed when organization continues to blindly follow the pattern adopted by others but does not work for them.

17. What are the benefits of using version control?

Ans:

• Tracking Changes
• Collaboration
• Backup and Recovery
• Branching and Forking
• Code Reviews
• Traceability and Accountability

18. Describe the branching strategies.

Ans:

Branching strategies are methodologies or patterns used in version control systems (VCS) to manage the development and release of software by organizing code changes into different branches. These strategies help facilitate collaboration, code stability, and the release process.

19. Can you describe the Shift left to decrease failure DevOps concept.

Ans:

The DevOps concept of shifting left aims to enhance security, performance, and other elements. For instance, if you take a look at all of the DevOps processes, you can say that security is checked before the deployment stage. can increase security by using a left shift technique throughout the development process, which is on the left.Not just during development but also during testing, we may integrate with all stages. By identifying flaws early on, this most likely increases security.

20. What is Blue/Green Deployment Pattern?

Ans:

The Blue/Green Deployment Pattern is a software release strategy used in continuous delivery and deployment to minimize downtime and reduce the risk associated with deploying new versions of an application or service.

21. Describe the use case for Amazon Elastic Container Service (ECS) in DevOps.

Ans:

The most common case is when have a microservice that need to deploy in an environment without any prior provisioning. And can achieve this by creating a Docker image of microservice and saving it in an image registry, such as t Elastic Container Registry (ECR) which can later be used in the Task Definition. Using technologies like Fargate, can then deploy this in ECS cluster.

22. How to solve challenge related to creating DevOps pipeline?

Ans:

In order to automate the process afterwards, it is crucial to try to reproduce as much of the pipeline locally as feasible in the beginning. To confirm that the workflow concept will really operate, do a number of tests.

23. What does some precautions teams need to consider before implementing DevOps?

Ans:

DevOps is more simply applying a new tools and/or forming a new “department” and expecting it work. In fact, DevOps is considered the culture in which development and operations teams work side by a side following a mutual framework.

Organizations do not need to explain the clear vision for DevOps practices. Applying DevOps initiatives is the notable change to both development and operation teams. Therefore, having clear roadmap, goals, and expectations for an integrating DevOps in organization will eliminate confusion and provide the clear guidelines from the start.

24. How can automate Testing in the DevOps lifecycle?

Ans:

Developers are obliged to commit all the source code changes to shared DevOps repository.Each time a change is made in a code, Jenkins-like Continuous Integration tools will be grab it from this general repository and deploy it for the Continuous Testing, which is done by a tools Selenium.

25. Distinguish difference between a centralized and distributed version control system (VCS)?

Ans:

Centralized Version Control System:

• All file versions are stored on the central server.
• No developer has copy of all the files on a local system.
• If central server crashes, all data from project will be lost.

Distributed Control System:

• Each developer has copy of all versions of a code on their systems.
• Enables a team members to work offline and does not rely on the single location for backups.
• There is no threat, even if a server crashes.

26. What does use of SSH?

Ans:

SSH stands for a Secure Shell and is an administrative protocol that lets users have the access and control the remote servers over an Internet to work using the command line. SSH is the secured encrypted version of tpreviously known Telnet which was unencrypted and not secure. This ensured that communication with the remote server occurs in encrypted form.SSH also has mechanism for a remote user authentication, input communication between client and the host, and sending the output back to client.

27. What does the Quality Assurance (QA) team work in DevOps?

Ans:

A test strategy and test plan that specify the testing technique, goals, scope, and resources needed for each software release or iteration must be developed by the QA team.

28. What does the benefits of HTTP and SSL certificate monitoring with Nagios?

Ans:

HTTP Certificate Monitoring:

• An Increased server, services, and application availability.
• Fast detection of a network outages and protocol failures.
• Enables a web transaction and web server performance monitoring.

SSL Certificate Monitoring:

• An Increased website availability.
• A Frequent application availability.
• It provides an increased security.

29. Explain virtualization with Nagios.

Ans:

Nagios can run on a various virtualization platforms, like a VMware, Microsoft Visual PC, Xen, Amazon EC2, etc. This provides capability to monitor the assortment of metrics on a various platforms and ensures a quick detection of service and application failures.

30. How does bare repository different from the standard way of initializing a Git repository?

Ans:

Standard (Non-Bare) Repository: Contains the actual project files, including the working directory where you edit and build your code.When you clone a repository using git clone, you create a standard repository with a working directory.Used for active development, making changes, and collaborating with other developers.

Bare Repository: Does not have a working directory; it only contains the Git version history, object database, and configuration files.Often used as a centralized repository or a remote repository for collaboration.Typically has a .git extension in its directory name and is used as a central point for pushing and pulling changes between developers.

31. Which CLI commands are used to rename files?

Ans:

To rename files in the command line, use the mv command followed by the current and desired filenames. For example, ‘mv old.txt new.txt’ renames “old.txt” to “new.txt” in the same directory. You can also move and rename a file by specifying a different directory like this: ‘mv old.txt /path/to/new/location/new.txt’. Caution: Be mindful of overwriting existing files with the ‘mv’ command.

32. Explain the process for reverting a commit has already been pushed and made public?

Ans:

Remove or fix a bad file in a new commit and push it to a remote repository. Then commit it to remote repository using:

git commit –m “commit message”

Create a new commit that undoes all the changes that made in bad commit. Use the following command:

git revert

Example: git revert 56de0938f

33. Explain the importance of identity and access management in a DevOps environment?

Ans:

In the DevOps context, identity and access management is crucial to ensuring that only authorized individuals may access the systems and resources. It assists in controlling user identities, resource access, and permissions.

Users have access to the resources needed for their jobs and responsibilities thanks to identity and access management. Additionally, it makes sure that access requests are confirmed and authenticated and aids in the detection and prevention of unwanted access

34. What does Git stash?

Ans:

A developer working with the current branch wants to switch to the another branch to work on something else, but developer doesn’t need to commit changes to unfinished work.. Git stash takes the modified tracked files and saves them on stack of unfinished changes that can reapply at any time.

35. Explain the concept of branching in a Git.

Ans:

Branching in Git is a fundamental concept that allows developers to create separate lines of development within a Git repository. Each branch represents a distinct path of code changes and allows for isolation of features, bug fixes, or experiments. Branches can be created, merged, and deleted, enabling collaborative and organized development while preserving the main codebase’s integrity.

36. Distinguish difference between the Git Merge and Git Rebase?

Ans:

Git Merge:

• To incorporate a new commits into the feature branch, use Git merge.
• Creates a extra merge commit every time need to incorporate changes but, it pollutes the feature branch history.

Git Rebase:

• As an alternative to the merging, can rebase the feature branch on to master.
• Incorporates all new commits in a master branch.It creates a new commits for every commit in original branch and rewrites a project history.

37. How does automation help in DevOps?

Ans:

Automation plays the crucial role in DevOps by streamlining software development. It eliminates the repetitive and time-consuming tasks like a testing and deployment, leading to faster time-to-market, enhanced a software quality, and reduced the chances of human error. Automation tools are instrumental in achieving benefits by automating the various aspects of software development process.

38. Define merge conflict in Git, and how can it be resolved?

Ans:

A Git merge conflict happens when have merge branches with the competing for commits, and Git needs help to decide which changes to incorporate in a final merge.

Resolve using the GitHub conflict editor:

This is done when merge conflict is caused after competing for a line changes. For example, this may occur when people make a different changes to same line of a same file on different branches in a Git repository.

39. Why does Continuous Integration needed?

Ans:

By incorporating the Continuous Integration for both the development and testing, it has been found that software quality has improved and time taken for delivering features of the software has drastically reduced.This also allows development team to detect and fix the errors at the initial stage as each and every commit to be shared repository is built automatically and run against unit and integration test cases.

40. Explain some basic Git commands.

Ans:

‘git init’: This function creates a new Git repository in the currently selected directory.

‘git clone ‘: Copies a remote Git repository to your local machine.

‘git add ‘: Stages a file for commit.

‘git commit -m “message”‘: Commits staged changes with a descriptive message.

‘git status’: Shows the status of files in the repository.

41. Explain the master-slave architecture of Jenkins.

Ans:

• Jenkins master pulls a code from remote GitHub repository every time there is code commit.
• It distributes a workload to all Jenkins slaves.
• On request from Jenkins master, the slaves carry out, builds, test, and produce test reports.

42. What is Jenkinsfile?

Ans:

Jenkinsfile contains definition of Jenkins pipeline and is checked into a source control repository. It is text file that allows the code review and iteration on pipeline. It permits the audit trail for the pipeline. There is single source of truth for pipeline, which can be viewed and edited.

43. What concepts are key aspects of Jenkins pipeline?

Ans:

Pipeline: User-defined model of CD pipeline. The pipeline’s code explains the entire build process, which includes the building, testing, and delivering an application.

Node: A machine that is part of Jenkins environment and capable of an executing a pipeline.

Step: Explains conceptually distinct subset of a tasks performed through an entire pipeline (build, test, deploy stages).

44. How can copy Jenkins from a one server to another?

Ans:

• Move job from one Jenkins installation to the another by copying corresponding job directory.
• Create copy of an existing job by making a clone of job directory with the different name.
• Rename existing job by renaming directory.

45. Name three security mechanisms Jenkins uses to an authenticate users.

Ans:

Jenkins uses the internal database to store a user data and credentials.

Jenkins can use Lightweight Directory Access Protocol (LDAP) server to the authenticate users.

Jenkins can be configured to an employ authentication mechanism that deployed application server uses.

46. How does custom build of a core plugin deployed?

Ans:

Steps to deploy the custom build of core plugin:

• Copy the .hpi file to $JENKINS_HOME/plugins.
• Remove plugin’s development directory.
• Create the empty file called .hpi.pinned.
• Restart a Jenkins and use the custom build of a core plugin.

47. How can temporarily turn off Jenkins security if the administrative users have locked themselves out of admin console?

Ans:

• When security is an enabled, the Config file contains the XML element named useSecurity that will be set to true.
• By changing this setting to be false, security will be disabled a next time Jenkins is restarted.

48. List the commands that can use to restart Jenkins manually?

Ans:

Two ways to manually restart the Jenkins:

• (Jenkins_url)/restart // Forces restart without waiting for a builds to complete.
• (Jenkins_url)/safeRestart // Allows all the running builds to complete before it restarts.

49. Which commands run Jenkins from the command line?

Ans:

The following command may be used to launch Jenkins from the command line:

java -jar jenkins.war

This command has to be run in the directory containing the ‘jenkins.war’ file. It starts Jenkins, a Java Virtual Machine (JVM)-based standalone web application. Please make sure Java is installed on your machine and that the ‘jenkins.war’ file is present in the specified place before running this command.

50. Which file is used to explain dependencies in Maven?

Ans:

Dependency information in Maven is defined within the “pom.xml” (Project Object Model) file. This file contains a ‘<'dependencies'>‘ section where you specify the external libraries or artifacts your project relies on. Maven uses this information to manage and fetch the required dependencies during the build process.

51. Explain the two types of pipelines in Jenkins, along with their syntax.

Ans:

Declarative Pipeline:

Syntax: Declarative pipelines use a simplified and structured syntax with a predefined set of stages and steps. The syntax is designed to be human-readable and is written in a block-style format using keywords like ‘pipeline’, ‘agent’, ‘stages’, and ‘steps’.

Scripted Pipeline:

Syntax: Scripted pipelines use a more flexible and powerful Groovy-based scripting syntax. This allows for more complex logic and customizations but can be less concise than declarative pipelines. Scripted pipelines often involve writing custom code within ‘node’ and ‘stage’ blocks.

52. How do you copy files and create a backup in Jenkins?

Ans:

Backup: Archive Jenkins configuration files, job configurations, and data directories regularly to create backups. You can automate this process with scripts or use built-in tools like the “ThinBackup” plugin.

Copy Files: To copy files within Jenkins jobs, use build steps like “Copy Artifacts” or execute shell commands to copy files to desired locations as part of your job’s workflow.

53. Describe the steps involved in creating a Jenkins job.

Ans:

Making a New Job: In the Jenkins dashboard, click “New Item,” provide a name, and select the job type (e.g., Freestyle Project or Pipeline).

Configure Build Steps: Define build steps, source code repositories, triggers, and post-build actions in the job’s configuration page.

Save and Build: Save the job configuration, and Jenkins will automatically trigger builds according to your defined criteria.

54. What does branching strategy in DevOps?

Ans:

Branching strategy is team’s agreement on how and when to create and merge the branches in version control. A branching strategy helps to define how the delivery team functions and how every feature, improvement, or bug fix is handled.

55. What is organization in Azure DevOps?

Ans:

An organization is used to connect a groups of related projects, helping to scale up enterprise. And can use a personal Microsoft account, GitHub account, or a work or school account. Examples of this could be different departments within the company like a sales, finance. And can also choose one organization for an entire company, or the multiple organizations based on the business units.

56. What is the difference between Automation and Orchestration in DevOps?

Ans:

Automation by itself can be considered as single entity – setting up the single task to run on its own. Some examples are – launching Virtual Machine, stopping a service.

Orchestration on other hand is automating more tasks together. The goal of orchestration is to be streamline and optimize frequent, repeatable processes. Some common examples are managing more servers and applications, batch processing of the transactions.

57. What does driver.close() and driver.quit() in WebDriver?

Ans:

These are two various methods used to close browser session in Selenium WebDriver:

driver.close(): This is used to close current browser window on which focus is set. In this case, there is only a one browser open.

driver.quit(): It closes all browser windows and ends WebDriver session using a driver.dispose method.

58. What is shift-left in DevOps?

Ans:

“Shift-left” in DevOps refers to the practice of moving tasks, such as testing and quality assurance, earlier in the software development process, typically to the left on the project timeline. The goal of shifting left is to identify and address issues and defects as early as possible in the development lifecycle, which ultimately leads to higher-quality software, faster development cycles, and cost savings.

59. How does DevOps different than Agile Methodology?

Ans:

DevOps is the practice or a culture that allows collaboration of the development team and operations team to come together for a successful product development. This involves making use of the practices like a continuous development, integration, testing, deployment, and monitoring of SDLC cycle.

Agile is nothing but software development methodology that focuses on the incremental, iterative, and rapid releases of a software features by involving the customer by means of a feedback. This methodology removes gap between the requirement understanding of clients and the developers.

60. How can DevOps help improve the customer satisfaction and drive business growth?

Ans:

DevOps can increase the customer satisfaction and drive business growth by providing a better software faster. DevOps teams can offer the features that satisfy customers’ expectations quickly by concentrating on the collaboration, continuous improvement, and customer feedback. It can result in a more loyal consumers and, ultimately, company’s growth.

61. What is CAMS?

Ans:

CAMS is acronym used to describe the four key DevOps principles. These include:

Culture: DevOps is upheld by culture of collaboration and transparency.

Automation: DevOps establishes the repeatable (or automated) systems to reduce an errors and save time.

Measurement: DevOps relies on a continuous performance tracking and feedback to the improve efficiency.

Sharing: DevOps teams share all the information and feedback, including the problems.

62. List some of the popular KPIs used for gauging the success of a DevOps.

Ans:

Deployment Frequency: How frequently code is put into use.

Change Failure Rate: Percentage of code changes causing production failures.

MTTR (Mean Time to Recovery): Time taken to recover from incidents. Lead Time for Changes: Time from code commit to deployment.

Deployment Success Rate: Percentage of successful deployments without issues.

63. What are the best strategies for improving DevOps performance?

Ans:

To enhance DevOps performance, adopt automation for tasks, implement CI/CD pipelines for efficient releases, and prioritize cross-team collaboration. Employ robust monitoring and feedback loops, integrate security into workflows, and embrace microservices and containerization for scalability. Cultivate a DevOps culture emphasizing shared responsibility, and continuously test and optimize performance while collecting relevant metrics and feedback.

64. How can DevOps be implemented securely?

Ans:

Security practices should be incorporated into the every step of the DevOps lifecycle. To implement them, teams can:

• Formalize the cybersecurity policies within the team.
• Use a privileged access management.
• Use the secrets management.
• A Segment network access.
• Automate a security processes.

65. How can DevOps help organizations reduce the risk of software failures?

Ans:

DevOps reduces a risk of software failures by promoting collaboration between the teams, continuous testing, and monitoring. It also encourages the culture of learning from mistakes to addressproblems quickly and prevent them from happening again.

66. How to launch Browser using WebDriver?

Ans:

To launch the Browser using WebDriver, following syntax is followed:

• WebDriver driver = new InternetExplorerDriver();
• WebDriver driver = new ChromeDriver();
• WebDriver driver = new FirefoxDriver();

67. What does Test Kitchen in Chef?

Ans:

Test Kitchen is the command-line tool in Chef that spins up instance and tests the cookbook on it before deploying it on actual nodes.

68. Why does SSL certificates used in Chef?

Ans:

SSL certificates are used between Chef server and client to ensure that every node has access to a right data. Each and every node has private and public key pair. The public key is stored at a Chef server. When SSL certificate is sent to a server, it will contain a private key of the node.The server compares this against a public key in order to identify a node and give the node access to required data.

69. Can one consider a DevOps as an Agile methodology?

Ans:

DevOps can be considered a complementary to Agile methodology but not an entirely similar.

70. Which commands are used to stop or disable the ‘httpd’ service when the system boots?

Ans:

To prevent or turn off the ‘httpd’ service from running at boot:

Stop the Service: Use ‘systemctl stop httpd’ to immediately stop the ‘httpd’ service.

Disable at Boot: Run ‘systemctl disable httpd’ to prevent ‘httpd’ from starting automatically on system boot.

71. How does chef-apply differ from chef-client?

Ans:

Chef-apply: chef-apply is run on a client system. chef-apply applies recipe mentioned in a command on the client system.

$ chef-apply recipe_name.rb

Chef-client: chef-client is also run on a client system. chef-client applies all cookbooks in a server’s run list to client system.

$ knife chef-client

72. Which open-source or community tools do use to make Puppet more powerful?

Ans:

Changes in a configuration are tracked using the Jira, and further maintenance is done through an internal procedures. A Version control takes a support of Git and Puppet’s code manager app. The changes are also passed through the Jenkin’s continuous integration pipeline.

73. Can you tell me the advantages of using Git?

Ans:

• A Data redundancy and replication.
• High availability.
• Only one Git directory per repository.
• A Superior disk utilization and network performance.
• A Collaboration friendly.
• Can be used for any sort of a project.

74. Explain the resources in Puppet?

Ans:

Resources are basic units of any configuration management tool. These are features of a node, like software packages or services. A resource declaration, written in catalog, explains the action to be performed on or with resource. When a catalog is executed, it sets the node to a desired state.

75. What does class in Puppet with example?

Ans:

Classes are named blocks in the manifest that configure different functionalities of a node, like services, files, and packages.The classes are added to the node’s catalog and are executed only when an explicitly invoked.

76. What does Ansible role?

Ans:

An Ansible role is the independent block of tasks, variables, files, and templates embedded an inside the playbook.

77. When should use ‘{{ }}’?

Ans:

Always use {{}} for a variables, unless have a conditional statement, such as “when: …”. This is because conditional statements are run through the Jinja, which resolves expressions.

Using brackets makes it easier to distinguish between the strings and undefined variables. This also ensures that an Ansible doesn’t recognize a line as dictionary declaration.

78. Describe the best way to make content reusable/redistributable?

Ans:

There are the three ways to make content reusable or redistributable in Ansible:

• Roles are used to managing the tasks in a playbook. They can be easily shared by Ansible Galaxy.
• “include” is used to add submodule or the another file to a playbook. This means code written once can be added to the multiple playbooks.
• “import” is improvement of “include,” which ensures that file is added only once. This is helpful when line is run recursively.

79. How does share Docker containers with the different nodes?

Ans:

It is possible to share a Docker containers on various nodes with Docker Swarm. Docker Swarm is the tool that allows an IT administrators and developers to create and manage the cluster of swarm nodes within Docker platform. A swarm consists of a two types of nodes: a manager node and a worker node.

80. Explain the architecture of Docker.

Ans:

Docker’s architecture is designed around a client-server model, consisting of several key components. At its core is the Docker Daemon, a background service responsible for managing containers. Users interact with Docker through the Docker Client, which sends requests to the Docker Daemon.

81. How can DevOps troubleshooting process be optimized?

Ans:

Every DevOps team should have established troubleshooting framework. Some of best practices for troubleshooting are to:

• Set a troubleshooting responsibilities within the team.
• Gather a relevant information including the metrics, logs, and errors.
• Hypothesize a potential causes and tick them off one by one.
• Closely monitor the behavior after issue has been fixed.
• Report on the issue resolution.

82. How are multiple containers managed by a single service?

Ans:

It is possible to run the multiple containers as single service with the Docker Compose. Here, every container runs in an isolation but can interact with the each other. All Docker Compose files are be YAML files.

83. What does Dockerfile used for?

Ans:

A Dockerfile is used for creating a Docker images using build command. With the Docker image, any user can run a code to create a Docker containers.

Once the Docker image is built, it’s uploaded in Docker registry. From a Docker registry, users can get Docker image and build a new containers whenever they want.

84. What does DevOps pipeline?

Ans:

A pipeline, in general, is set of automated tasks/processes explained and followed by a software engineering team. DevOps pipeline is the pipeline which allows the DevOps engineers and software developers to efficiently and reliably compile, build and deploy software code to production environments in hassle free manner.

85. Instead of YAML, what can use as an alternate file for a building Docker compose?

Ans:

To build a the Docker compose, a user can use JSON file instead of the YAML. In case a user needs to use the JSON file, he/she should specify filename as given:

Docker-compose -f Docker-compose.json up

86. Distinguish difference between a registry and a repository?

Ans:

Registry: A Docker registry is an open-source server-side service used for hosting and distributing Docker images. In registry, user can distinguish between the Docker images with tag names. Docker has its own default registry called the Docker Hub

Repository: The repository is a collection of multiple versions of Docker images. It is saved in the Docker registry . It has a two types: a public and private repositories

87. How does one create a Docker container?

Ans:

A user can either build the Docker image or pull existing Docker image (like MySQL) from Docker Hub. Now, Docker creates the new container MySQL from an existing Docker image. Simultaneously, the container layer of a read-write filesystem is also created on a top of image layer.

Command to create the Docker container: Docker run -t –i MySQL

88. What are the advantages of using Nagios Log Server in DevOps?

Ans:

Nagios Log Server offers the many benefits, including:

• Automatically fixes issues.
• Giving quicker reponses to the issues.
• Monitors the business infrastructure and process.
• Simple to install and configure.
• A web-based user interface for simple log management.

89. How can AWS contribute to DevOps?

Ans:

AWS is the powerful tool that can contribute to DevOps in many ways. AWS can help with the provisioning and managing infrastructure, deploying applications, automating tasks, and more. AWS can also help the teams work together more effectively by providing central place to store and share information.

90. What are the Docker-supporting cloud computing platforms?

Ans:

The following are cloud platforms that Docker runs on:

• Amazon Web Services.
• Microsoft Azure.
• Google Cloud Platform.
• Rackspace.

91. Explain the purpose of the expose and publish commands in Docker?

Ans:

Expose:

• Expose is the instruction used in a Dockerfile.
• It is used to expose the ports within Docker network.
• It is the documenting instruction used at a time of building an image and running a container.

Publish:

• Publish is used in the Docker run command.
• It can be used outside the Docker environment.
• It is used to map the host port to a running a container port.

92. How does Nagios help in continuous monitoring of systems, applications, and services?

Ans:

Nagios enables the server monitoring and ability to check if sufficiently utilized or if any task failures need to be addressed.

• Verifies a status of servers and services.
• Inspects health of infrastructure.
• Checks if applications are working to be correctly and web servers are reachable.

93. Explain the configuration file and its location in the Nagios.

Ans:

The major configuration file consists of a several directives that affect how can Nagios operates. The Nagios process and CGIs read the config file.

A sample major configuration file will be placed into the settings directory: /usr/local/Nagios/etc/resource.cfg

94. What does mean by Nagios Remote Plugin Executor (NPRE) of Nagios?

Ans:

A Nagios Remote Plugin Executor (NPRE) enables to execute a Nagios plugins on Linux/Unix machines. It can monitor the remote machine metrics (disk usage, CPU load, etc.)

95. How can Jenkins be secured?

Ans:

Securing Jenkins is crucial to protect sensitive data and maintain system integrity. Key steps include strong authentication, plugin management, securing master-agent communication, build environment isolation, regular backups, monitoring and logging, keeping Jenkins updated, and using security plugins for access control.

96. What does active and passive checks in Nagios?

Ans:

Actively:

• Active checks are an initiated as result of Nagios process.
• An Active checks are regularly scheduled.

Passively:

• A Passive checks are initiated and performed through an external applications/processes.
• A Passive checks results are submitted to be Nagios for processing

97. Explain “blue-green deployments” and how they minimize downtime in DevOps.

Ans:

Blue-green deployments are a DevOps deployment strategy that minimizes downtime during software releases. In a blue-green deployment, two identical environments, labeled “blue” and “green,” are maintained in parallel. Initially, the live production system, say “blue,” serves user traffic.

98. What does a “Canary Release” in a DevOps pipeline serve?

Ans:

Mitigate Risk: Gradually expose a limited subset of users or systems to new code changes.

Early Issue Detection: Monitor for problems and defects in a controlled environment.

Minimize Impact: Ensure that issues affect only a small group, reducing user impact.

Validate Changes: Confirm that new features or changes work as expected in a production setting.

Gather Data: Collect valuable data and user feedback for informed decisions.

99. What does Nagios Network Analyzer?

Ans:

• It provides the in-depth look at all the network traffic sources and security threats.
• It provides the central view of a network traffic and bandwidth data.
• It allows the system admins to gather high-level information on health of the network.
• It enables to be proactive in a resolving outages, abnormal behavior, and threats before affect the critical business processes.

100. What role does “Chaos Engineering” play in DevOps?

Ans:

“Chaos Engineering” plays a crucial role in DevOps by helping organizations proactively identify weaknesses and vulnerabilities in their systems, infrastructure, and processes. This discipline involves intentionally injecting controlled disruptions or failures into a system to observe how it responds under stressful conditions.