Devops

Question 1

What is git branching for?

Answer 1

Git branching is a tool for development that assist when working with a team. A branch can be made for a specific person to work in and push code to without affecting the main branch. From there the code can be reviewed before merging into the main branch. This allows an easy way to attempt new features or updates to make sure they are working and tested before actually affecting the main branch.

Question 2

What is git merging for?

Answer 2

Merging is Git’s way of putting a forked history back together again. The git merge command lets you take the independent lines of development created by git branch and integrate them into a single branch.

Question 3

What is a pull request?

Answer 3

Pull requests let you tell others about changes you’ve pushed to a branch in a repository on GitHub. Once a pull request is opened, you can discuss and review the potential changes with collaborators and add follow-up commits before your changes are merged into the base branch.

Question 4

What does a gitignore do?

Answer 4

The purpose of gitignore files is to ensure that certain files not tracked by Git remain untracked. The .gitignore file tells Git which files to ignore when committing your project to the GitHub repository. gitignore is located in the root directory of your repo.

Question 5

Why would a developer leverage cloud computing rather than running their applications off of their own server?

Answer 5

The cloud offers businesses more flexibility overall versus hosting on a local server. And, if you need extra bandwidth, a cloud-based service can meet that demand instantly, rather than undergoing a complex (and expensive) update to your IT infrastructure.

Question 6

What are regions and availability zones?

Answer 6

AWS region is a physical location where data centers are clustered around the globe. Groups of these data centers are called AZ’s. Each region consists of 3 isolated, and physically separated AZ’s which lets the user operate on production apps and databases.

Question 7

What is autoscaling?

Answer 7

AWS Auto Scaling lets you build scaling plans that automate how groups of different resources respond to changes in demand. You can optimize availability, costs, or a balance of both.

Creates all of the scaling policies and sets targets for you based on your preference.

Question 8

What is a security group for?

Answer 8

Controls the traffic that is allowed to reach and leave the resources that it is associated with.

For example, after you associate a security group with an EC2 instance, it controls the inbound and outbound traffic for the instance.

Question 9

What is EC2?

Answer 9

Ec2 stands for elastic compute cloud. It is a web service provided by amazon web services that allows users to rent virtual servers in the cloud. These can be accessed and managed remotely over the internet. Ec2 instances are designed to provide scalable computing capacity.

Question 10

What is an RDS?

Answer 10

Relational Database Service: it is a database instance running with Amazon RDS encryption to easily set up, operate, and scale relational databases.

Question 11

What is an S3?

Answer 11

S3 stands for simple storage service. It is a cloud-based object storage service provided by amazon web services. Key benefits of s3 are its scalability and reliability. It is designed to automatically scale to accommodate changing needs.

Question 12

What is an AMI?

Answer 12

AMI stands for amazon machine image. It is a preconfigured virtual machine image used to create ec2 instances on the aws cloud. Amis also provide a way to back up and restore ec2 instances. Users can create an ami of an existing ec2 instance and use it to launch a new instance.

Question 13

What is an EBC for?

Answer 13

Amazon Enhanced Brand Content (EBC) is a premium content feature that enables sellers to showcase their products through enhanced image and text placements on Amazon.

Question 14

What do we use SSH for?

Answer 14

SSH connections have mostly been used to secure different types of communications between a local machine and a remote host, including:

Secure remote access to resources

Remote execution of commands

Delivery of software patches and updates

Interactive and automated file transfers

Question 15

What is docker and why would a developer use it?

Answer 15

Docker is a platform that simplifies the process of developing, shipping, and running applications by using containerization technology. Developers use Docker to ensure consistent environments across development, testing, and production stages, simplify deployment, and improve application isolation and security.

Question 16

What is a container?

Answer 16

A container is a lightweight, stand-alone, and executable software unit that bundles an application along with its dependencies and runtime environment. Containers allow applications to run reliably across different computing environments, by isolating them from the host system and other containers.

Question 17

How is a container different from a virtual machine?

Answer 17

A container is different from a virtual machine (VM) in that it shares the host’s operating system kernel and resources, while a VM runs a full operating system on emulated hardware. Containers are more lightweight, start faster, and require fewer resources than VMs.

Question 18

What is an image? How are images related to containers?

Answer 18

An image is a snapshot of a container’s filesystem and includes everything needed to run the application (code, libraries, environment variables, etc.). Images are the basis for creating containers. When a container is launched, it is instantiated from a specific image, with a read-write layer added on top of the image’s read-only layers.

Question 19

What is a dockerfile? How is a dockerfile related to images?

Answer 19

A Dockerfile is a script containing instructions to build a Docker image. It specifies the base image, application code, dependencies, environment variables, and configurations needed to create a custom image. The Dockerfile is used by the docker build command to generate an image.

Question 20

What does it mean to “containerize” my application?

Answer 20

To “containerize” an application means to package it as a container, ensuring that it can run consistently and reliably across different environments.

Question 21

What is a docker volume, and why would a developer use one?

Answer 21

A Docker volume is a mechanism for persisting data generated by and used by Docker containers. It provides an abstraction layer for storing data outside the container’s filesystem. Developers use Docker volumes to manage data, share data between containers, and ensure data persistence even when containers are removed or updated.

Question 22

What is dockerhub, and why would a developer use it?

Answer 22

Docker Hub is a cloud-based registry service for sharing and distributing Docker images. Developers use Docker Hub to store and share their custom images, as well as to find and use pre-built images created by others. This simplifies the process of deploying applications and managing dependencies.

Question 23

What are some of the common docker commands used for?

Answer 23

docker build: Builds an image from a Dockerfile.

docker pull: Downloads an image from a registry (e.g., Docker Hub).

docker push: Uploads an image to a registry.

docker run: Creates and starts a new container from an image.

docker ps: Lists running containers.

docker stop: Stops a running container.

docker rm: Removes a stopped container.

Question 24

What is devops for?

Answer 24

DevOps is a set of practices, tools, and a cultural philosophy that automated and integrate the process between software development and IT teams.

Question 25

What is Continuous Integration?

Answer 25

Continuous Integration (CI) is the practice of automating the integration of code changes from multiple contributors into a single software project. (It is a primary DevOps best practice, allowing developers to frequently merge code changes into a central repository where builds and tests then run)

Question 26

What is Continuous Delivery?

Answer 26

Continuous delivery is an extension of continuous integration since it automatically deploys all the code changes to a testing and/or production environment after the build stage. (This means that on top of automated testing, we will have an automated release process, and we can deploy our application any time by clicking a button)

Question 27

What is Continuous Deployment?

Answer 27

A strategy in software development where code changes to an application are released automatically into the production environment.

Question 28

How does Devops relate to Agile?

Answer 28

Agile and DevOps are associated with one other because they both improve teamwork among individual software developers. They provide a way for accelerating the development lifecycle without the difficulties that result from engineers working on various aspects.

Question 29

What is Jenkins and why would a developer use it?

Answer 29

Jenkins is an open-source continuous integration/delivery and deployment automation software DevOps tool written in the Java programming language. It is used to implement CI/CD workflows, called pipelines.

Advantages:

Free and fully open-source

Rich Plugin Ecosystem to enhance the functionalities

Easy Integration to EC2

Question 30

What is a pipeline?

Answer 30

A suite of plugins which supports implementing and integrating continuous delivery pipelines into Jenkins.

A continuous delivery pipeline is an automated expression of your process for getting software from version control right through to your users and customers.

Question 31

What is a job?

Answer 31

A given set of tasks that runs sequentially as defined by the user. Any automation implemented in Jenkins is a Jenkins Job. We can create and build Jenkins jobs to test our application or project

Question 32

What is a github webhook?

Answer 32

Used to trigger the action whenever Developers commit something into the repository. It can automatically compile or deploy applications if there are no errors detected.

Question 33

What is linting / static code analysis and why would a developer use it?

Answer 33

Linting is the automated process of the checking the source code of a program.

It is used to write better code with features similar to spellchecking, issue detection, and the differences between issues.

It also allows several developers to adhere to the same coding guidelines.

Question 34

What is SonarCloud?

Answer 34

SonarCloud is a cloud-based code analysis service to detect code quality issues such as unused variables/imports and security issues, to maintain security, reliability, and maintainability