Continuous Integration (CI)
In today's rapidly advancing and highly competitive global IT
industry, agility, quality, and time to market have become the key contributors to
software' overall success. Whether an organization is delivering a new product or
rolling out new features of existing software, there is tremendous pressure to rapidly
produce and deliver while keeping up with the customer demands and ensuring consistent
business growth. While organizations cannot guarantee the success of a software product,
they can certainly adopt methodologies and practices that drastically increase the
probability of a product's success and ensure its popularity among users.
Continuous Integration
is one such practice that helps improve the efficiency of
software development workflow and streamlines it to be more manageable, comprehensive,
agile, secure, and reliable.
In this article, we delve into the concept of Continuous
Integration to elucidate its importance and comprehend how it streamlines software
development workflows, making it highly beneficial for organizations.
What is Continuous Integration (CI)?
A software engineering practice, Continuous Integration (CI),
requires developers to integrate source code changes regularly into a shared code
repository, several times a day. Automated testing is done against each iteration of the
build to identify and assert the new code’s correctness before integration. This
helps avoid issues at the final integration stage, before the release, and allows the
team to deliver higher quality software with more predictable delivery schedules.
Moreover, it enables application development teams to release
incremental code changes to the production environment, quickly and regularly leveraging
the capabilities like frequent code commit, comprehensive monitoring, observability,
etc., which allows early and automated detection of issues, visibility, and fast
feedback.
Continuous integration, in short, is a continuous provision
of all the elements required for a successful new release, for which it follows an
automated process that ensures secure and frequent integration of the source code into
the source baselines.
Continuous Integration In DevOps:
Continuous Integration is an essential aspect of DevOps and
the first stage of the three-phased automated software release pipeline of DevOps-
Continuous Integration, Continuous Deployment,
and Continuous Delivery. It is
implemented first in the DevOps development cycle, as it helps build the entire workflow
and serves as a prerequisite for continuous delivery stages of software testing,
deployment, and release.
The main objective of Continuous Integration is to prevent
integration problems by bringing developers together and merging their source code
changes into a central repository, where automated builds and tests are executed. This
helps the team to find and address issues faster, improve software quality, and reduce
the validation time while enabling better transparency and insight into the software
development and delivery process and ensuring the seamless release of new software
updates.
Why Continuous Integration?
From facilitating collaboration among team members to
enabling them to create more dependable code, the reasons for implementing continuous
integration during the software development lifecycle are numerous, a few of which are
listed below:
- Helps boost code test
coverage.
- Allows easier and faster
detection of bugs.
- Helps teams to build
repeatable processes.
- Prevents breaks and issues in
builds and code.
- Helps build DevOps and Agile
workflows.
- Automates the process of code
deployment to the production environment.
- It helps run simultaneous
procedures, which saves time and effort.
- Decreases code review time by
enabling early detection of bugs and discrepancies.
- Allows teams to execute code
testing in the real world, facilitating better quality, performance, and
reliability.
- Activates build and
compilation processes freeing team members to focus on other tasks.
Prerequisites of Continuous Integration:
For a successful implementation of Continuous Integration
into the existing software development workflow, organizations must ensure the
development teams consider the CI prerequisites, as these ensure the accuracy of the
process and help the team be more productive. Moreover, these prerequisites are the
pillars of continuous integration and help increase focus, identify and remove
bottlenecks, reduce resource utilization, and enable the team to deliver new software
updates to users faster and more frequently.
Hence, the prerequisites of Continuous Integration
are:
- Version Control: Also known as
the source code management system, Version Control is a reliable method for
centralizing and preserving changes made in the source code over time so that
when the code is modified the team can still access the previous revisions. It
is an effective way of communicating and resolving editing conflicts between
multiple developers working on the same codebase. This is enabled by a variety
of tools like Git and Subversion.
- Virtual Machines: Another
critical requirement of Continuous Integration is to have a spare server or
virtual machine when building your system. This prevents issues and delays in
validating each integration and code change and makes the process more
streamlined.
- Hosted CI Tool Solutions: Apart
from virtual machines and servers, teams can also opt for hosted CI tool
solutions, as they help maintain the whole process and ensure its
scalability.
- Automated Tools: From build to
testing, Continuous Integration relies on automation for a variety of functions.
Hence you will have to install a suitable CI tool like Jenkins, TeamCity,
Bamboo, GitLab, etc. for continuous, consistent, and quality integration and
delivery.
Now that we know the basic requirements of Continuous
Integration, let us move on to understanding how CI works.
Continuous Integration Workflow:
Once the prerequisites are in place, the team works on
implementing the CI workflow, which involves the following steps:
- Code & Change Input: In the
first step of CI workflow, developers input code into their private workspaces.
After which, the changes are committed to the shared
repository.
- Monitor & Analyze Changes: Once the changes are committed, the CI server monitors
the repository and analyzes the changes as they
occur.
- Build & Test: The CI then
builds the system and executes automated unit and integration tests to identify
issues and bugs in the code. Here, the server also releases deployable artifacts
for testing.
- Assign & Report: A build
tag is assigned to the version of the code just built by the CI server, which
also provides the team reports of the successful build. If the build or tests
fail, the server alerts the development team.
- Defect Rectification: Finally,
reported discrepancies are fixed by the team as soon as
possible.
Continuous integration continues to integrate and run tests
throughout the entire project, to further validate changes and ensure the frequent and
rapid release of software/software updates.
Continuous Integration Best Practices:
The process of Continuous Integration in the DevOps software
development pipeline can be further enhanced by adopting CI best practices that enhance
its accuracy, facilitate transparency, and allows the team to save time on build and
testing. These best practices are:
- Maintain a code
repository.
- Automate Build and
Deployment.
- Enable build
self-testing.
- Regularly commit to the
baseline every day.
- Ensure every commit to
baseline should be built.
- Every bug-fix commit should be
fixed immediately and must come with a test case.
- Keep the build fast with
automated deployment.
- Perform regular and early
check-in.
- Build and test everything
after every minute change.
- Maintain stronger source code
control.
- Don't rely on an integrated
development environment (IDE).
- Act on metrics and
data.
- Ensure it is easy for everyone
to get the latest deliverables.
- Make sure everyone has access
to see the latest build results.
- Use a clone of the production
environment for testing.
Advantages of Continuous Integration:
Used alongside agile software development workflow,
Continuous Integration is a valuable and well-established practice that significantly
reduces integration problems and allows the team to develop cohesive software more
rapidly. It offers various benefits to the development team, product managers, and the
overall organization, enabling them to better plan and execute their marketing
strategies.
Other prominent advantages of CI include:
- Improves developer
productivity by automating tasks, enabling them to deliver more value to
customers.
- Allows early and improved
error detection and rapid resolution.
- Increases efficiency, reduces
integration risks and breaks and enhances services agility.
- Helps deliver updates and
features faster and more frequently.
- Improves team collaboration
and enhances communication.
- Improves system integration
and feedback loop.
- Facilitates transparency and
visibility.
- Improves quality and
testability.
- Enables developers to develop
functional and quality code.
- Enables better transparency
and insight into the software development delivery process.
Disadvantages of Continuous Integration:
The benefits of Continuous integration though outweigh the
disadvantages it offers, it is still important for us to be aware of them as they can
impact the entire DevOps release cycle. Therefore, the following are some of the common
disadvantages of Continuous Integration:
- Requires initial setup time
and CI server training.
- Constructing automated test
suites requires a considerable amount of work.
- Requires additional servers
and environments.
- It is essential to develop
suitable test procedures.
- Delay may occur during code
integration if multiple developers integrate their code simultaneously.
Continuous integration Vs. Continuous Delivery Vs. Continuous Deployment:
Continuous Integration, Continuous Delivery, and Continuous
Deployment are three closely related concepts of DevOps that are focused on different
aspects of software development and delivery processes.
Continuous Integration ensures code quality
through automated tests before each code integration, whereas
Continuous delivery is focused on continuously
delivering integrated code to the test or production environment. The only common aspect
between these two is that they require manual intervention. Continuous
deployment goes one step further from the delivery
phase and allows the team to automatically deploy changes that have passed the continuous
integration, to the production without any human intervention.
Tools for Continuous Integration (CI):
A prominent reason for the popularity of Continuous
Integration is that it automates build and test execution, which prevents manual efforts
and allows the team to focus on other critical tasks. However, currently, there is a
wide range of CI tools available, choosing the suitable one from which can be extremely
tedious.
Therefore, here is a list of some of the most popular
continuous integration tools for you to choose from:
- Buddy: The most powerful, smart, and easy-to-configure CI/CD
tool, Buddy is web-based and self-hosted continuous integration and delivery
software designed to lower the entry threshold to DevOps. It is used for
projects that use code from the Bitbucket and GitHub repositories. Buddy is a
commercial tool with a user-friendly interface, minimalistic material design,
Docker support, etc.
- Jenkins: A free, open-source continuous integration tool, written
using Java, Jenkins is a server-based CI application that requires a web server to
operate on. It is a widely used tool that allows developers to build, integrate, and
test code automatically, immediately after they are committed to the source
repository. It helps developers to easily identify bugs early in the lifecycle and
deploy software/updates faster.
- TeamCity: A powerful and intelligent commercial CI server from
JetBrains, TeamCity uses automatic framework and configuration to perform code
coverage, code analysis, avoid code duplication, etc. It is an easy-to-install tool,
with a user-friendly interface and quality features like comprehensive VCS
integration, on-the-fly build progress reporting, and more.
- Bamboo: A server-based CI and deployment tool from Atlassian,
Bamboo is a popular choice for automating software release management. It works
seamlessly with JIRA software and Bitbucket and supports various languages and
technologies like CodeDeploy, Ducker, Git, AWS, Amazon S3 buckets, etc.
- GoCD: An open-source continuous integration server, used for
modeling and visualizing complex workflows with ease, GoCD allows continuous
delivery and provides an intuitive interface for building CD pipelines. It supports
parallel and sequential execution and can easily configure dependencies. Moreover,
with this tool developers can deploy to production securely.
- GitLab CI: Another free, open-source continuous integration tool,
GitLab CI is highly scalable, easy to install and setup, and provides a friendly
user interface. Designed to improve Github’s overall experience, this tool
offers a modern UX with container support and various other beneficial
features.
- Circle CI: Circle CI is a flexible continuous integration and
delivery platform that can run in any environment and supports multiple coding
languages, version control systems, container systems, and delivery mechanisms. This
tool helps reduce bugs, improves software quality, and can be hosted on-premise or
used through a cloud offering.
- Codeship:
A powerful CI tool, Codeship automates the development
and deployment workflow and provides full control over system design, its
customization, and optimization. It is a Software as a Services that helps teams to
implement and optimize CI and CD in the Cloud and develop applications to achieve
fast, secure, and frequent code delivery.
Conclusion:
Continuous Integration has become the need of the hour for
modern and high-performing organizations that want to better cater to their more
informed and tech-savvy customer base with low-risk and rapid releases. It is one
effective software development and delivery strategy that streamlines SDLC and allows
businesses to quickly adapt to changing business and user requirements.
In short, by adopting Continuous Integration organizations
not only improve their development model by reducing risks and catching bugs quickly but
also ensure rapid delivery of enterprise-grade software.