CI/CD Automation. Why automate Continuous Integration and Continuous Delivery in software development? 

Continuous Integration, Delivery, and Deployment are software development practices that have gained great popularity in recent years. If we were to sum it up in one word, it would be automation. All three of these practices boil down to automating the testing and deployment process, minimizing (or eliminating) the need for human action, reducing the risk of errors, and facilitating software development and deployment to the point that any developer in the team can do it. Learn more about the key practices and benefits of CI/CD automation.  

Definition of Continuous Integration (CI) and Continuous Delivery (CD) 

Continuous Integration  

CI (Continuous Integration) involves the frequent, regular integration of current changes in the code into the main application repository. Usually, developers integrate their changes at least once a day, which, with a team of a few or a dozen people, results in many integrations being performed every day. Each integration is verified by the use of automation in the project (including automatic tests) to detect possible errors in the integrated code as soon as possible. Using this approach leads to a significant reduction in the number of integration problems and facilitates the faster creation of consistent software. 

Continuous Delivery 

CD is a software engineering practice involving the regular release of subsequent software versions in short cycles. This means that a new version of the entire software is built with each compilation. This does not mean that the software is immediately released to the production environment. However, nothing holds you back from doing so if there is a need to.  

This slight difference regarding the automatic implementation of changes directly in the production environment distinguishes continuous delivery from continuous deployment – in which each compilation of the entire software ends with the release of the next version in the production environment. Development teams ensure that new features are added in small packages so that the possible release of a new version of the software can be performed quickly and at any time. In practice, this maximizes the possibility of obtaining feedback on the software quickly, from both a business and technical perspective. 

Also read:  

• What is DevOps?  
• Continuous testing – shift-left testing  

The challenges of Continuous Integration and Continuous Deployment  

Kent Beck first wrote about Continuous Integration in his book “Extreme Programming Explained”, published in 1999. The idea of CI was: if regular code integration is good, why not do it all the time? “All the time” in this case means every time someone makes a change to the version control system. However, the problem with continuous integration, delivery, and implementation is that configuration is not an easy task and takes a long time, especially if the team is dealing with it for the first time or the decision has been made to implement the process in an existing project.  

However, the benefits of these practices are worth the time taken. This will result in fewer errors, facilitating their identification and repair, and ultimately in the development of better software quality.  

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Why automate CI/CD?

Continuous Integration (CI). Key aspects of effective continuous integration 

Let’s take a closer look. Over the past few years CI has become standard in agile software development methodologies. Initially, combined with running automatic unit tests in the local developer environment, it aimed to ensure that the developer would not introduce code changes that could cause errors in the application. Over time, this method has evolved.  

Currently, compilations are run on continuous integration servers that build the project and run automated tests – either automatically, with each change added by developers, or periodically. The result (in the form of reports and logs) is generated once the building process is completed. Currently, the continuous integration approach is used not only in agile methodologies but also in other software development methodologies. 

In addition to conducting unit and integration tests, you can also run static and dynamic tests, measure and profile performance, create documentation based on source code, and simplify manual Quality Assurance processes. In this way, Continuous Integration also ensures the continuous quality control of the software. 

Well-functioning Continuous Integration is based on meeting certain prerequisites and using several basic practices. When implementing it, first of all, three things should be taken care of: 

1.  Version Control Tool 

Everything in the project must be recorded in one version control tool: code, scripts, databases, compilation and deployment scripts, and whatever is needed to create, install, run, and test the application. 

2. Automated Build Tool 

You should be able to run the compilation using the command line. The basic tool can be a simple command line program that will compile the program you are creating and then run tests. It can also be a complex collection of build scripts that call each other in the right order. Regardless of the mechanism, a person or computer must be able to run build, build, run tests, and deploy in an automated way using the command line. Scripts should be treated like code – they must be tested and constantly refactored so that they are stable, well-organized, and easy to understand. 

3. Agreement of the entire team  

Continuous Integration is a practice, not a tool. It requires the development team to be disciplined and committed. Everyone in the team must often make changes to the repository and assume that the most important task while working on the project is to repair changes that impact the application negatively. If the team does not follow these rules, the correct implementation of CI may not be effective and will not lead to a satisfactory improvement in the quality of software development. 

Advantages of Continuous Integration compared to the traditional approach

Compared to the traditional approach, where changes made to the source code are compiled, tested, and integrated once in a while (once a week or less), the use of a continuous integration approach has many benefits: 

• Detecting build/integration problems early, so that they are easier to fix (repaired continuously and not in “last minute mode”, just before the main version of the software is ready for release). 
• The team gets immediate feedback on the quality, functionality, and impact of the written code on the entire system. 
• As part of this process, automated tests are performed, thanks to which it is possible to immediately control whether the project architecture is correct and the quality of the code is good. Tests are performed as part of the processes of compiling, building, and implementing changes (deployment) in various environments. 
• Early access to the current version of the software (before official release) for test or demonstration purposes.  

Also read: CI tools – DevOps monitoring systems  

Best practices in the Continuous Integration process

The optimal benefits of a Continuous Integration process can be obtained by following the procedures recognized in the team, which calls for discipline, as I mentioned earlier. There are also proven, good practices, which will significantly increase the success of implementing this process if followed properly. They consist of the following: 

1. Frequent code integration – the most important practice in Continuous Integration. The code should be integrated at least several times a day. Sending changes regularly has other benefits – changes are delivered in smaller packages, which reduces the risk of a compilation error, and also makes it easier to search for possible changes (fewer files to search). This also minimizes the risk of conflicting with other programmers’ code in the case of work requiring changes in multiple files. In the event of a local workstation failure that would result in the loss of local changes in the code, the developer does not have to write everything from scratch. He can start from the stage of changes introduced in the last integration. 

2. Managing the workspace – the development environment must be carefully managed. First of all, this increases productivity. Developers should always start a new job with the current, working version of the code from the main branch of the repository. They should be able to run builds, tests, and deploy the application in their local environment. Running applications in a local environment should use the same automated processes as in Continuous Integration servers. 

3. A comprehensive set of automatic tests – it is necessary to have a set of automatic tests to make sure that the application works properly. Unit, integration, and acceptance tests are most important from the Continuous Integration perspective. A blend of these should provide a very high level of confidence that none of the changes introduced compromise the stability of the application.  

4. A short process of building and testing a project – compiling, building, and performing tests should not exceed 5-10 minutes. If for any reason this process takes too long, you may experience issues such as: 

• Developers getting impatient – they may stop performing the full procedure (for example, skipping the testing stage), which will cause more build errors on the continuous integration server. 
• The Continuous Integration process can take so long that many changes can be integrated until the build is restarted – finding the one that causes errors can be very time-consuming. 
• Less frequent integration of changes by developers due to the time-consuming process – waiting a couple of hours to complete builds and tests is a waste of time and resources.  

Continuous Delivery (CD) 

Continuous integration is the basis for robust, modern software development. This is a factor enabling the implementation of even more advanced techniques. In Continuous Integration, when all tests are successfully completed, we gain confidence that the software works. However, how can you ensure the software will work in the target environment? Will it work with other apps? Finally, how can we deliver it to end users? Here the Continuous Delivery (CD) approach comes in handy. 

In essence, Continuous Delivery consists in minimizing the time needed to make changes to the application and reducing the risk of problems that may also arise during this process. It may consist of several phases, such as: 

• Discovery – in which ideas, general functioning, and functionalities are analyzed to gain a wider understanding of the problem and to think of potential solutions. 
• Defining – in which formal acceptance criteria and project work are the basis for further development. 
• Development – in which the product is built and tested functionally. 
• Acceptance – in this phase, high-level acceptance tests are carried out and confirmations are obtained from shareholders. 
• Implementation – a change is introduced into production. 
• Verification – in which changes are analyzed based on all data to ensure that the intended impact has been achieved. 

Each phase is a kind of checklist defining what is needed for the changes to go forward. Sometimes the high-level phases are divided into more detailed ones. For example, a development phase may include specific sub-phases:  

• technical architecture, 
• build or compilation, 
• code review. 

Regardless of the complexity of individual phases, the tasks related to them can be undertaken by many people with different skills. Therefore, tasks can be performed in parallel, but they should remain independent. 

Continuous Delivery automates the process of deploying software to different environments in the project. Some of them can be used to perform various automated tests, such as:  

• integration tests, 
• acceptance tests, 
• non-functional tests, such as performance or penetration tests.  

Also, do not forget to carry out manual tests that can detect new classes of defects that automatic ones are usually unable to find. 

Benefits of Continuous Delivery (CD) 

Implementing a Continuous Delivery approach has many benefits, including: 

1. Time savings 

In medium and large companies, software and infrastructure are usually created and operated by many separate teams. Each implementation of a new version of the application must be coordinated. A date that will suit both teams should be set for the introduction of a new change.  

Moreover, information about the new version should be distributed (for example, what areas of the application will be subject to changes, whether a new configuration is required, what the changes in integration are, etc.). In addition, teams must provide the required files, and so on – procedures may vary depending on the formalities and maturity of processes in the organization.  

In general, all the necessary activities will certainly take a few hours, and sometimes even a few days. Often, this process also includes downtime caused by various factors. And because we should avoid downtime in business hours, it sometimes turns out that implementations are carried out at night or during weekends. This can demotivate the operation teams responsible for the implementation, and hence leave them only one step removed from making mistakes. Introducing Continuous Deployment by automating tasks can save a lot of time, shorten the process from a few days to even a few minutes, and minimize the amount of stress in operational teams. A well-configured tool will allow for a virtually maintenance-free implementation, coordinated by one or several people without the need to involve entire teams.  

2. Shorter implementation cycles 

Companies that perform manual releases and deployments usually do so once a week or even less frequently. Less frequent releases lead to prolonged development processes and ultimately slow down the time to market. If the software is updated quarterly, the introduction of a new, small feature or a significant patch may unnecessarily stretch past the deadline and result in losing customers. For example, the owner of an e-commerce platform for which a certain stage of the purchasing process was poorly designed (which causes difficulties in shopping) will have to wait 3 months before the patch is implemented. During this time, the store may lose a huge number of customers, and thus real money. Automatic deployment can completely eliminate this type of problem. 

3. Faster feedback 

The best way to get valuable feedback on a product is to implement it in a production environment where it will be used by real users. This way, you can measure how involved they are in different parts of the system. Users also often express opinions about the app and suggest changes. 

Unfortunately, this task is not simple when you create, for example, tools for internal use. You can then ask a few people to test it on one of the test environments, but this comes with challenges. This requires man-hours, as the test environment must be fully prepared and configured with all the necessary data that will be deleted at the end. It is a time-consuming and complicated process.  

With manual releases, which often go hand-in-hand with an infrequent implementation period, the feedback cycle is very slow, which contradicts the idea behind the agile software development process. Communication is also not always perfect – working with a group of people comes with a risk of misunderstandings occurring. It may turn out that the first implementation of the functionality does not meet the original expectations. In such a situation, discussions (and therefore feedback) are inevitable.  

Slow implementation cycles therefore lead to a slowdown in the development of the application, frustrating not only the team but also the stakeholders. Target users, being aware of how long the implementation of subsequent updates takes, may not even ask for corrections or suggest various facilities – instead, they will start using an application produced by your competitors, who take better care of this aspect. In the long term, slow implementation cycles translate into a loss of application quality and users. 

4.  Reliability of releases 

Manual implementation usually does not take place very often. This means that each release contains a lot of changes, which in turn increases the risk of failure. When large updates cause too many problems, engineers and managers look for ways to improve the stability of the next release, often by creating further procedures and checklists. 

That creates a vicious circle, because more processes require even more effort in subsequent releases, and thus more time. This makes software release cycles even longer, which translates into the need to change procedures to shorten this time. The way out of this vicious circle is to automate the stages or even the entire release process. So once this process becomes reliable and faster, nothing holds you back from increasing the number of releases with smaller changes at once. Time saved through automation frees up competencies that can be used to further streamline the automated dispensing process. 

5. It is easier to find the source of the problem 

When the implementation causes an error in the software (and it contains only one or two new features or bug fixes themselves), it is quite easy to determine which of the changes is the source of the error. Large packages, where there are many changes in different parts of the application per release, make it difficult to find the source of problems and extend the search and repair time. Due to the many changes included in the release (the level of complexity of the package due to various dependencies), this takes longer. 

6.  Architectural freedom 

Current trends in software engineering are moving from monolithic applications to distributed systems, consisting of small components (microservices). Smaller apps or services are easier to maintain, and due to scalability requirements, they must work on different devices – often on multiple devices at the same time. Manual deployment of individual microservices, if there are hundreds of them, seems to be impossible to carry out in a failure-free manner and in a satisfactory timeframe. Automatic deployment allows you to configure the release of applications optimally to ensure the software is reliable.  

7.  Advanced Quality Assurance techniques 

Imagine a vacation search engine whose owner wants to improve the search algorithm. You can deploy both the old and new versions of the engine at the same time and run queries on both. By defining the appropriate metrics, you can easily evaluate the functioning of the new algorithm. Thanks to them, if, for example, the old engine returns better results for some queries – you can use this data to improve the new one. Automatic implementation does not guarantee quality assurance but it provides the basis for applying advanced techniques to achieve it.  

CI/CD Automation vs. Manual Deployment process

The main practices used in both approaches (Continuous Integration and Continuous Deployment) are the same. The difference is the stage of automating implementation to the production environment, as presented below.  

As I have mentioned, the goal of the Continuous Delivery approach is to automate each stage of the deployment cycle to the last pre-production environment, so that changes can be made to the target environment at any time. In Continuous Deployment, changes are delivered directly to the production environment. The difference is the means of implementation – automatic or manual.  

The practice of Continuous Implementation is complicated, as the processes used in continuous integration are not able to cover all the necessary stages for its correct implementation in the project. It is necessary to use additional tools to test and control different parts of the system (for example, performance, operational readiness, validation of integration, etc.). 

Automated testing in the CI process

Automated testing plays a crucial role in the testing process within the CI/CD pipeline. Whenever new code is introduced, it is important to ensure that it does not impact existing functionalities. This is achieved through test automation, where test scripts are executed to validate the new changes. By including automated testing in the CI/CD pipeline, teams can ensure higher test coverage and catch bugs earlier.  

Automation and continuous integration go hand in hand, as the CI process requires continuous testing to ensure the quality of the software. The most popular testing tools like Selenium, JUnit, and TestNG allow developers to automate the execution of rigorous testing on their codebase. These tools also enable teams to take advantage of CI to automate various testing scenarios. By employing the right testing tools, teams can create and execute test scripts easily, ensuring that their code meets quality standards. 

Conclusions: CI/CD is your way to continuous improvement

Nowadays, it is difficult to imagine any modern IT project without CI/CD practices. Automating the processes of Continuous Integration and Continuous Delivery allows us to shorten the time of implementing changes and release software reliably and more often. Furthermore, we get feedback from users faster. I encourage you to read the second part of the article, in which I will take a closer look at the CI/CD software delivery process and discuss specific testing practices along with an overview of the best CI/CD tools.