Module 1: What is DevOps

What is DevOps?

The word DevOps is a combination of two words Development and Operations. Before getting into what DevOps is, let us get an idea about the two teams involved in software development. The development team is responsible for developing, designing, and building the application. The operation team deals with the deployment and testing of the application. If there are problems with the application, the operation team also provides feedback to the development team. Now let us get to the history of DevOps.

History of Devops

Let us see some important events of DevOps :

2007-2008: The DevOps idea was started

2009: In the initial stage the first conference was ” Deploys a day: Dev and Ops cooperation of flicker.”  Another conference called “DevOps Days in Ghent, Belgium” also happened.

2010:DevOps days conference happened in the United States at mount view, calif.

2012: Allana browns at puppet creates a state of DevOps report

2014: Publishing the annual “State of DevOps report”

2017: Forrester Research calls 2017 “The Year of DevOps”

2018: 30 DevOps day conferences were scheduled across the united states.

Why did we need DevOps?

As we know about the problems faced in traditional models like in the waterfall model there is a problem of a one-way stream of work. Due to which if there is any mistake the whole process repeats and there is no interaction with customers. Now, this is solved in agile by splitting the whole development plan into several iterations for a better level of production efficiency.  The agile model also includes customer interaction with the company to rectify the mistakes. But there is another problem faced in Agile too.

Here, the problem arises when the development team continuously changes the code for better performance and sends the code to the operations team for testing. But there may be a delay in the operations team feedback in situations like if the developers sent code for review at night but due to the unavailability of the operations team, there will be a delay in the project feedback.

So, DevOps is the solution to this problem. DevOps is a practice or a methodology in which the development team and operations team work together by including automation at the initial stages. So they can work on  rapidly changing systems, fix bugs, and help to deliver a good quality of software in time.

Waterfall Model 

Let’s consider developing software in a traditional way using a Waterfall Model in this Devops Tutorial.

In the above diagram in this Devops Tutorial, you will see the phases it will involve:

• ­In phase 1 – Complete Requirement is gathered and SRS is developed
• In phase 2 – This System is Planned and Designed using the SRS
• In phase 3 – Implementation of the System takes place
• In phase 4 – System is tested and its quality is assured
• In phase 5 – System is deployed to the end users
• In phase 6 – Regular Maintenance of the system is done

Waterfall Model Challenges

The Water-fall model worked fine and served well for many years however it had some challenges. In the following diagram the challenges of Waterfall Model are highlighted.

In the above diagram in this Devops Tutorial you can see that both Development and Operations had challenges in the Waterfall Model.  From Developers point of view there were majorly two challenges:

• After Development, the code deployment time was huge.
• Pressure of work on old, pending and new code was high because development and deployment time was high. On the other hand, Operations was also not completely satisfied.

There were four major challenges they faced as per the above diagram in this Devops Tutorial:

1. It was difficult to maintain ~100% uptime of the production environment.
2. Infrastructure Automation tools were not very affective.
3. Number of severs to be monitored keeps on increasing with time and hence the complexity.
4. It was very difficult to provide feedback and diagnose issue in the product.

DevOps Architecture:

Let us now discuss different phases of DevOps architecture:

• Plan – In DevOps planning plays an important role. In this stage, all the requirements of the project and everything regarding the project like time for each stage, cost. etc are discussed. This will help everyone in teams to get a brief idea about the project. 
• Code – In this Stage the code is written over here according to the client’s requirements. Here the code is divided into small codes called Units. This is done to get a clear picture of the code. For example, if the team is doing a project on an online -Ekart application then the login part is divided as one unit, after login the page which shows all the categories is divided as another unit, user profile as another unit, etc. 

Some of the examples of the tools used are Git, JIRA

• Build – In this stage Building of the units is done. Some of the examples of the tools used are maven, Gradle.
• Test – Testing of all units is done in this stage. So we will get to know where exactly the code is having bugs and if there are mistakes found it is returned. Some of the examples of the tools used are Selenium, PYtest
• Integrate – In this stage, all the units of the codes are integrated. That means in this step we will be creating a connection between the development team and the operation team to implement Continuous Integration and Continuous Deployment. An example of the tool used is Jenkins. 
• Deploy – In this stage, the code is deployed on the client’s environment. Some of the examples of the tools used are AWS, Docker.
• Operate – Operations are performed on the code if required. Some of the examples of the tools used are Kubernetes, open shift.
• Monitor – In this stage monitoring of the application is done over here in the client’s environment. Some of the examples of the tools used are Nagios, elastic stack.

How is DevOps different from traditional IT in this Devops Tutorial?

Let us take a look at some key differences between traditional IT and DevOps in this Devops Tutorial.

Let us take a look at the workflow of traditional IT methods and DevOps to get a better understanding of the differences between them.

In traditional IT methods [specifically waterfall method] the developer writes the code in their coding environment. Once the development is complete they will inform the operations team to test the code. 

Now the operations team will be taking the code from the coding repository and will be passing through some test cases. If there are any bugs detected then it’s sent back again to the development team. This is continued till the bugs are resolved. So as we can see the main problem is, there is a lot of time is wasted because the testing is done only when the coding is completed. So if there is a small mistake by developers. For finding that small mistake the whole testing process is done again. So the solution for this problem is implementing testing at the early stages [development stage].