Interview Tips for DevOps

1) Explain what DevOps is?

It is a newly emerging term in the IT field, which is nothing but a practice that emphasizes the collaboration and communication of both software developers and deployment(operations) teams. It focuses on delivering software products faster and lowering the failure rate of releases.

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

The key aspects or principle behind DevOps is

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

3) What are the core operations of DevOps with application development and with infrastructure?

The core operations of DevOps are

Application development

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

Infrastructure

• Provisioning
• Configuration
• Orchestration
• Deployment

4) Explain how “Infrastructure code” is processed or executed in AWS?

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

5) Explain which scripting language is most important for a DevOps engineer?

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

6) Explain how DevOps is helpful to developers?

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

7) List out some popular tools for DevOps?

Some of the popular tools for DevOps are

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

8) Mention at what instance have you used the SSH?

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 in order to facilitate secure encrypted communications between two untrusted hosts over an insecure network.

9) Explain how you would handle revision (version) control?

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.

10) What are the types of HTTP requests?

The types of HTTP requests are

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

11) What are the key components of DevOps?

The most important components of DevOps are:

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

12) Name a few cloud platforms which are used for DevOps Implementation

Popular Cloud computing platforms used for DevOps implementation are:

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

13) Give some benefits of using a Version Control system

• 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 like 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

14) Explain Git Bisect

Git bisect helps you to find the commit which introduced a bug using binary search.

15) What is the build?

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.

16) What is Puppet?

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

17) Explain two-factor authentication

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

18) Explain the term ‘Canary Release’.

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.

19) What types of testing are important to ensure that the new service is ready for production?

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

20) What is Vagrant?

A vagrant is a tool that can create and manage virtualized environments for testing and developing software.

21) What is the use of PTR in DNS?

Pointer record which is also known as (PTR) is used for a reverse DNS lookup.

22) What is Chef?

It is a powerful automation platform that transforms infrastructure into code. In this tool, you can use write scripts that are used to automate processes.

23) What are the prerequisites for the implementation of DevOps?

Following are the useful prerequisites for DevOps Implementation:

• At least one Version Control Software
• Proper communication between the team members
• Automated testing
• Automated deployment

24) Name some best practices which should be followed for DevOps success.

Here, are essential best practices for DevOps implementation:

• The speed of delivery means time taken for any task to get them into the production environment.
• Track how many defects are found in the various
• It’s important to measure the actual or the average time that it takes to recover in case of a failure in the production environment.
• The number of bugs being reported by the customer also impacts the quality of the application.

25) Explain the SubGIt tool

SubGit helps you to migrate SVN to Git. It also allows you to build a writable Git mirror of a local or remote Subversion repository.

26) Name some important network monitoring tools

Some most prominent network monitoring tools are:

• Splunk
• Icinga 2
• Wireshark
• Nagios
• OpenNMS

27) What is the quickest way to open an Ubuntu terminal in a particular directory?

To open an Ubuntu terminal in a particular directory, you can use custom keyboard short cut.

To do that, in the command field of a new custom keyboard, type genome – terminal – – working – directory = /path/to/dir.

28) Explain how you can get the current color of the current screen on the Ubuntu desktop?

You can open the background image in The Gimp (image editor) and then use the dropper tool to select the color on a specific point. It gives you the RGB value of the color at that point.

29) Explain what Memcached is?

Memcached is a free and open-source, high-performance, distributed memory object caching system. The primary objective of Memcached is to enhance the response time for data that can otherwise be recovered or constructed from some other source or database. It is used to avoid the need to operate an SQL database or another source repetitively to fetch data for a concurrent request.

Memcached can be used for

• Social Networking->Profile Caching
• Content Aggregation-> HTML/ Page Caching
• Ad targeting-> Cookie/profile tracking
• Relationship->Session caching
• E-commerce -> Session and HTML caching
• Location-based services-> Database query scaling
• Gaming and entertainment->Session caching

Memcache helps in

• Speed up application processes
• It determines what to store and what not to
• Reduce the number of retrieval requests to the database
• Cuts down the I/O ( Input/Output) access (hard disk)

Drawback of Memcached is

• It is not a persistent data store
• Not a database
• It is not an application-specific
• It cannot cache large object

30) Mention some important features of Memcached?

Important features of Memcached includes

• CAS Tokens: A CAS token is attached to an object retrieved from a cache. You can use that token to save your updated object.
• Callbacks: It simplifies the code
• getDelayed:?It reduces the delay time of your script which is waiting for results to come back from a server
• Binary protocol:?You can use binary protocol instead of ASCII with the newer client
• Igbinary:?Previously, a client always used to do serialization of the value with complex data, but with Memcached, you can use igbinary option.