DevOps Interview Questions

2. Mention what the key aspects or principles behind DevOps are?

The key aspect or principle behind DevOps is

• Infrastructure as code
• Continuous deployment
• Automation
• Monitoring
• Security

The core operations of DevOps are

Application development

• Code building
• Code coverage
• Unit testing
• Packaging
• Deployment

Infrastructure

• Provisioning
• Configuration
• Orchestration
• Deployment

In AWS,

• The code for infrastructure will be in simple JSON format
• This JSON code will be organized into files called templates
• These templates can be deployed on AWS DevOps and then managed as stacks
• Later the CloudFormation service will do the Creating, deleting, updating, etc. operation in the stack

A simpler scripting language will be better for a DevOps engineer. Python seems to be very popular.

DevOps can be helpful to developers to fix the bug and implement new features quickly. It also helps for clearer communication between the team members.

Some of the popular tools for DevOps are

• Jenkins
• Nagios
• Monit
• ELK (Elasticsearch, Logstash, Kibana)
• Jenkins
• Docker
• Ansible
• Git

I have used SSH to log into a remote machine and work on the command line. Besides this, I have also used it to tunnel into the system to facilitate secure encrypted communications between two untrusted hosts over an insecure network.

My approach to handling revision control would be to post the code on SourceForge or GitHub so everyone can view it. Also, I will post the checklist from the last revision to make sure that any unsolved issues are resolved.

The types of HTTP requests are

• GET
• HEAD
• PUT
• POST
• PATCH
• DELETE
• TRACE
• CONNECT
• OPTIONS

If a Linux-build-server suddenly starts getting slow, you will check for the following three things

The most important components of DevOps are:

• Continuous Integration
• Continuous Testing
• Continuous Delivery
• Continuous Monitoring

Popular Cloud computing platforms used for DevOps implementation are:

1. Google Cloud
2. Amazon Web Services
3. Microsoft Azure

• The version Control system allows team members to work freely on any file at any time.
• All the past versions and variants are closely packed up inside the VCS.
• A distributed VCS helps you to store the complete history of the project so in case of a breakdown in the central server you can use your team member’s local Git repository.
• Allows you to see what exact changes are made in the file’s content

A build is a method in which the source code is put together to check whether it works as a single unit. In the build creation process, the source code will undergo compilation, inspection, testing, and deployment.

Puppet is a useful project management tool. It helps you to automate administration tasks.

Two-factor authentication is a security method in which the user provides two ways of identification from separate categories.

A canary release is a pattern that reduces the risk of introducing a new version of software into the production environment. It is done by making it available in a controlled manner to a subset of the user. Before making it available to the complete user set.

You need to conduct continuous testing to ensure that the new service is ready for production.

• For Firefox, WebDriver driver = new FirefoxDriver();
• For Chrome, WebDriver driver = new ChromeDriver();
• For Internet Explorer or IE, WebDriver driver = new InternetExplorerDriver();

• It supports only web-based applications.
• It does not support the Bitmap comparison.
• No vendor support for Selenium compared to commercial tools like HP UFT.
• As there is no object repository concept, the maintainability of objects becomes very complex.

Selenium can be used to execute the same or different test scripts on multiple platforms and browsers concurrently to achieve distributed test execution. Selenium allows testing under different environments, saving the execution time remarkably.

The driver.close command closes the focused Browser window. But, the driver.quit calls the driver.dispose method which closes all browser windows and also ends the WebDriver session.

Yes, it is. With the help of a Jenkins plugin, we can build projects one after the other. If one parent job is carried out, then automatically other jobs are also run. We also have the option to use Jenkins Pipeline jobs for the same.

The way to secure Jenkins is mentioned below.

• Ensure that the global security is on
• Check whether Jenkins is integrated with the company’s user directory with an appropriate plugin
• Make sure that the Project matrix is enabled to fine-tune access
• Automate the process of setting rights or privileges in Jenkins with the custom version-controlled script
• Limit physical access to Jenkins data or folders
• Periodically run security audits

To create a backup, all we need to do is to periodically back up our JENKINS_HOME directory. This contains all of the build configurations of our job, our slave node configurations, and our build history. To create a backup of our Jenkins setup, just copy this directory. We can also copy a job directory to clone or replicate a job or rename the directory.

Jenkins Pipeline can be defined as a suite of plugins supporting both implementation and integration of Jenkins continuous delivery pipeline.

Continuous integration or continuous delivery pipeline consists of build, deploy, test, and release. The pipeline feature is very time-saving. In other words, a pipeline is a group of build jobs that are chained and integrated with a sequence.

Every Puppet node or Puppet agent has got its configuration details in Puppet Master, written in the native Puppet language. These details are written in a language that Puppet can understand and are termed Puppet Manifests. These manifests are composed of Puppet codes, and their filenames use the .pp extension.

For instance, we can write a manifest in Puppet Master that creates a file and installs Apache on all Puppet agents or slaves that are connected to the Puppet Master.

To configure systems with Puppet in a client or server architecture, we have to use the Puppet agent and the Puppet master applications. In a stand-alone architecture, we have to use the Puppet apply application.

It is the main directory for code and data in Puppet. It consists of environments (containing the manifests and modules), a global modules directory for all the environments, and your Hiera data.