Digital Skynet - Continuous Integration vs Continuous Delivery vs Continuous Deployment

Continuous Integration vs Continuous Delivery vs Continuous Deployment

September 18, 2020
#Develpment #QA #BPA

Modern development practices are hard to imagine without CI/CD. Let’s look at what practices hide behind this acronym and how they affect the industry.

As you can see, CI clearly stands for continuous integration while there are two ways to interpret CD: continuous delivery and continuous deployment. While they can work together, there are some crucial differences that determine how your project will end up. As a result, this also has an impact on your business. So, which one is better and deserves your time? We’ll try to give you all the necessary information to make this choice.

Results of CI/CD implementation

What Is Continuous Integration?


Before delving into the differences and comparisons, let’s first get familiar with the different aspects of this practice. Like we mentioned earlier, continuous integration is the CI part of the CI/CD acronym. As a result, it’s the one constant element that is necessary for the successful implementation of this practice. But does it actually do?

Continuous integration is a development practice that increases the frequency of code integration into the main repository. Every programmer merges their code with the main branch multiple times a day. With the help of automated build and automated tests, that more often than not go hand-in-hand with CI, this makes the code cleaner and development faster. Because of the frequency of these integrations if a defect of some kind pops up then it’s immediately clear where lies the problem. You don’t have to spend hours trying to find the source.

This also gets rid of the so-called integration hell. It’s when everybody waits for a certain day to merge all of their changes at once into the release branch. The problems of this outdated practice are immediately obvious. It takes a lot of time and if by chance your code is not 100% perfect good luck trying to debug it. Overall, the main reason for the implementation of CI/CD is the drastically increased efficiency of the development process.

Requirements:

  • Automatic tests need to be written for every feature
  • Dedicated server monitoring the main repository and running the preprogrammed tests
  • Developers need to form a habit of merging their changes at least daily

Advantages:

  • Fewer bugs on production thanks to the automatic tests
  • Easier release process, since issues are being solved during the early stages
  • Immediate alerts whenever the build fails the tests, which means faster fixing process
  • Reduced testing costs, since the server can run hundreds of them in any given second
  • The QA team has more time to do other important tasks

What Is Continuous Delivery?


Now here is where the common confusion over the meaning of CD comes in. The first practice going by these letters is continuous delivery. It works in tandem with the previous practice and is responsible for getting new versions of your product to the client as quickly as possible. That’s right, you can test and release your app with just a simple click of a button. And that’s not devilry, it’s delivery.

The time period can also be adjusted. New versions can be released every day, week, or however often you need. The earlier you deliver and the smaller batches are the better. That way any arising problems are easier to identify and fix. Also, if you deliver frequently your client is always aware of what you are working on without even needing to contact the project manager. In our experience, the communication between us and our clients became vastly more efficient after we adopted CI/CD. However, there is something that is even better.

Requirements:

  • Fully implemented continuous integration with a robust test suite
  • Deployments have to be automated and have a manual trigger to launch them
  • Adoption of feature flags so that unfinished features don’t go to production

Advantages:

  • An extremely easy deployment process
  • The releases are more frequent which means that the feedback loop is accelerated
  • Less pressure on the developers and small changes can be deployed without extra busywork

What Is Continuous Deployment?


Deployment takes this practice to another level. Remember us telling that a simple click of a button will release your changes? Well, even that’s not needed anymore. Continuous deployment automates your development pipeline even further. Now everything you change is automatically released to your clients.

No human intervention is needed. If an automatic test is failed only then your changes won’t be deployed. That way the feedback loop becomes even faster. As developers finish a piece of code in the project the client can see it within minutes. No need to drag the release out for days, it’s available right then and there. Since the developers are paid by the hour this has saved our clients substantial sums of money, while also improving communication, the speed of development, while the quality of software only goes higher.

Requirements:

  • An impeccable test suite, since it directly affects the quality of the final product
  • Documentation needs to keep up with the frequent deployments
  • Feature flags should become standard practice for your team so that important decision can be easily coordinated with other departments

Advantages:

  • The speed of development is vastly increased since there are no downtimes in between deployments
  • The releases are smaller and therefore less likely to break things. By virtue of this, the speed with which the issues are fixed is also increased
  • Your clients witness the development process. Their project grows and improves right before their eyes.

How Do These Practices Work Together?


Just like you’ve already noticed and how we have already mentioned, there is one CI and two CDs. Continuous integration is necessary for the work of the other two practices. It makes sense why. There’s no way to deliver or deploy code frequently if the main repository is updated only once a month.

When it comes to continuous delivery vs continuous deployment it’s basically a choice of one or the other. While they are mutually exclusive, any of them is better than none. The main difference is whether the deploy to production is manual or not. Just as illustrated below.


Continuous Delivery vs Continuous Deployment

From Continuous Integration to Continuous Deployment


So, we have established that all of the practices that we have covered in this article are essentially a logical evolution of the development process. So how do you get from one step to another successfully?

First of all, make sure to have DevOps engineers as part of your team. As a general rule, the sooner you start adopting these technologies the quicker you adapt to them and can move up this proverbial ladder. A perfect way to start is the automation of tests on a brand new project. Since the stakes aren’t quite as high and there is still plenty of time before deadlines. As the project develops so does your testing culture.

For projects that are already ongoing and have clients awaiting new iterations then it’s also better to start off gradually. Begin with basic unit test automation and leave the more complex end-to-end ones for the future. The main focus should be the automation of deployments as soon as possible. When you have done that, you get more time to dedicate to the perfection of more complex tests.

Whenever daily deployments feel like second nature to you it’s time to look into the continuous deployment. By that point, your development company should work like a well-oiled machine. With an increased number of releases, all of your departments should be in tune with changes that are made. That way you guarantee that all of your staff are on the same page and your clients are satisfied with the product that they have ordered from you.


In Conclusion


As development practices improve everybody wins. The developers have a better work process, the QA team doesn’t have to spend time on the same tedious tests, the project managers have a streamlined and easily trackable workflow, and the clients get their projects sooner, cheaper, and of higher quality. That’s the value of CI/CD. If that sounds like the perfect approach to make your idea a reality, then you can always send us a message and we’ll make it happen.

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