CI/CD is a method for automating app development stages, including continuous integration, delivery, and deployment. It uses automation to resolve integration issues and deliver code changes rapidly and reliably, facilitating better collaboration between development and operations teams.
In most cases, developing a business app is an arduous, time-consuming endeavor. This is thanks to, in part, the app development and delivery process. From the conceptual pre-design phase, through the design and development phases, and finally into the rollout and support phases, there are a lot of steps and tasks involved in getting an app out the door. In fact, depending on the complexity of the app and a business' development resources, building and releasing high-quality new software can take anywhere from a few months to upwards of a year.
CI/CD aims to change all of that.
CI/CD is an approach to app delivery that integrates automation into app-development stages. CI/CD stands for continuous integration/continuous delivery (or deployment). Having grown out of agile-development practices, CI/CD is an umbrella term that includes a collection of operating principles that empower DevOps teams to more quickly and with agility implement code changes to apps.
CI/CD is a response to many of the challenges associated with traditional software development, where lengthy development cycles and manual processes often lead to delays, errors, and frustration among development and operations teams. The CI/CD approach aims to automate and streamline the entire software delivery pipeline, from code changes to production deployment, fostering a culture of collaboration, efficiency, and reliability. To do so, CI/CD relies on continuous integration (CI), continuous delivery/continuous deployment (both referred to as CD), and continuous testing (CT).
Continuous integration is the first pillar of CI/CD. It focuses on the frequent and automated integration of code changes into a shared version control repository—typically multiple times a day. Each integration triggers automated build and testing processes to detect issues early in the development cycle. CI ensures that code changes from different team members do not introduce conflicts, and that code quality is maintained, allowing developers to work concurrently without disrupting the stability of the codebase.
Continuous delivery extends the CI process by automating the delivery of code changes to various environments, such as staging or testing, after they pass automated tests. Continuous delivery does not automatically push changes to production; instead, it provides a controlled release process that depends on some form of manual intervention before the changes are deployed to the users. This ensures that software updates are always in a deployable state, ready for release at any time. With continuous delivery, organizations reduce their risk of deployment-related issues while also promoting the fast releases of high-quality software.
Continuous deployment takes automation further by automatically deploying code changes to production as soon as they pass automated tests—without the need for manual intervention. This approach is well-suited for organizations aiming for rapid and frequent releases. While it requires automated governance and a high degree of confidence in automated testing and a dependable infrastructure, continuous deployment can significantly reduce lead time between code changes and their availability to end-users.
Continuous testing is the final aspect of CI/CD, ensuring that automated tests are consistently executed throughout the development process. This involves unit, integration, functional, and performance testing (among others), to verify code quality and operability.
CT provides real-time feedback to developers, helping them identify and address issues promptly, maintaining the reliability and stability of the application as it evolves. Most CI/CD pipelines today include security scanning alongside the testing process.
Altogether, CI/CD produces a system where developers can rely on a high degree of automation and monitoring to improve app development.
CI/CD pipelines are automated workflows that streamline the software development process by integrating continuous integration and continuous delivery/deployment practices. This allows developers to merge code changes into a shared repository, triggering automated builds and tests to detect issues early while helping keep the codebase stable and free of conflicts.
The pipeline consists of a sequence of stages, many of which may occur simultaneously as the code is continuously refined and improved:
Plan
In this initial stage, project managers gather requirements from customers and stakeholders, create a project roadmap, and build a backlog of tasks. Agile project management tools like Scrum and Kanban are often integrated to manage these tasks.
Develop
This stage focuses on simplified coding and fast feedback. Continuous development principles are applied, with code being constantly validated for correctness. Early integration of security measures ensures high-quality code.
Build
Here, teams work in short iterations to create runnable instances of the product. Any issues preventing the product from passing the build stage are addressed immediately, ensuring a smooth transition to the next phase.
Test
Automated tests are employed to verify the functionality of the code. This phase helps identify and fix bugs before they reach the customer. Advanced testing includes security vulnerability scans, aligning with DevSecOps practices.
Deploy
Tested and validated code is sent to a staging environment for further review. Approved changes are then automatically deployed to production, ensuring reliable and efficient releases.
Operate
Once in production, the application is closely monitored to identify trends and potential problems. Operational insights inform future updates, maintaining the application's performance and reliability.
As addressed above, CI describes how development teams regularly implement and test small, incremental code changes, which are then merged into a shared version-control repository. These ‘check-ins’ are then verified by an automated build, so that any problems with the code can be identified and resolved quickly. CI allows teams of developers to work concurrently on the same app without creating conflict.
Here are some of the capabilities and characteristics of continuous integration:
One advantage of continuous integration is that changes are automatically implemented on a regular basis. That said, you may not want every change instantly visible to your users—such as incomplete changes that are not yet ready for deployment.
Feature flags (also called feature toggles, feature switches, feature controls, etc.) allow developers to control code access. For example, a feature flag can be used to mark which new lines of code are ready for testing. Using feature flags to manage incomplete changes helps minimize the risk of rollback.
Continuous integration is powered by automated tests. By automating tests, developers can make code changes earlier and more regularly to increase quality without slowing down the development process.
Reliable automated tests are a safeguard against code changes that might otherwise break functionality. As a bonus, automatically generated test-coverage reports can help you evaluate your tests for improved effectiveness.
Application and software code can be very convoluted and astoundingly complex, so it’s no surprise when it occasionally breaks. The difficult part is knowing which breaks are the highest priority, and which can be relegated to backlogs for later. Unfortunately, because break fixes are reactionary rather than preventative, often there is not much time to make that call.
Automated CI tools can help you identify breaks more quickly, and automatically designate the higher priority fixes, so you can address the most critical issues more quickly.
Before going further, it’s worth reiterating that although CD is used to describe both continuous delivery and continuous deployment, the two terms are not synonymous. Here, we address the similarities, differences, and benefits of each:
In continuous deployment, as developers successfully build and test applications—and make ongoing changes to applications—these applications and updates are automatically delivered to UAT (user acceptance testing). The code is tested for all aspects of functionality, and if it passes, the working version of the application is pushed to production automatically.
This occurs without the need for an approval cycle, meaning that developers will need to ensure that their test site is effective and reliable. The advantage is that teams can deploy multiple apps or updates in a very short amount of time, and with minimal manual action.
Continuous delivery is similar to continuous deployment, except that once the app has been validated in UAT, it still has to wait on the development team to manually trigger deployment. This allows developers to implement feedback and make ongoing fixes, only releasing the final product when they feel it is absolutely ready. Continuous delivery must consider manual review and deployment times.
Continuous deployment relies on a set of core principles to enable rapid and reliable software delivery. These principles guide organizations in optimizing their software deployment process and implementing this form of CD effectively.
Continuous deployment emphasizes the creation of a consistent and dependable software delivery process. Every step, from code changes to deployment, should be repeatable and predictable, reducing the risk of errors and ensuring the reliability of the entire pipeline.
Automation is at the heart of continuous deployment. All repetitive and manual tasks—including testing, building, and deployment—should be automated whenever possible. Automation increases efficiency and consistency while minimizing the risk of human error.
Managing code changes and configurations using version control systems is fundamental in continuous deployment. It ensures that the history of code changes is well-documented, facilitates collaboration among team members, and allows for easy rollbacks in case of issues.
Continuous deployment encourages addressing challenging and complex tasks early in the development process. By tackling difficult issues at the beginning, teams can identify potential roadblocks and resolve them sooner, preventing delays later in the deployment process.
Quality is paramount in continuous deployment. Automated tests should be an integral part of the deployment pipeline and should never be skipped over or trivialized for the sake of reaching a deadline. This ensures that code changes maintain the desired functionality and performance.
In continuous deployment, 'done' signifies that code changes are not only completed but also ready for release. Each code change should be thoroughly tested, validated, and prepared for deployment. This approach eliminates the need for last-minute adjustments and delays during the release process.
Continuous deployment promotes a culture of shared responsibility across development, operations, and other relevant teams. Everyone involved in the software delivery pipeline collaborates to ensure a faster, more reliable, and effective deployment process.
Continuous deployment is an ongoing process that encourages continuous improvement. Teams should regularly assess their deployment practices, measure results, identify bottlenecks, and prioritize enhancements. Continuous improvement ensures that deployments become more efficient and routine over time.
Continuous delivery is likewise built on certain fundamental principles designed to help organizations achieve a dependable, streamlined delivery pipeline. These principles include:
Continuous delivery emphasizes the importance of having consistent and dependable deployment processes. Every step in the delivery pipeline—from code integration to deployment—should be repeatable and reliable, reducing variability and the potential for errors.
To ensure the quality and reliability of software, continuous delivery advocates running a variety of tests in parallel. These tests include unit tests, integration tests, security scans, and performance tests, among others. Parallel testing accelerates the feedback loop, allowing teams to identify and address issues early in the development cycle.
Continuous delivery prioritizes the execution of phases in the delivery pipeline that provide rapid feedback. By addressing quick-feedback stages early, teams can detect and rectify issues sooner, reducing the overall time and effort required for testing and validation.
Continuous delivery acknowledges that parameters, configurations, and variables can change frequently. It is crucial to design the delivery pipeline to accommodate these changes while maintaining the integrity of the deployment process. This adaptability ensures that the pipeline remains robust and responsive to evolving requirements.
Continuous delivery promotes simultaneous generation of feedback from various sources, such as automated tests, code analysis, and user acceptance testing. Parallel feedback mechanisms help identify critical issues promptly, allowing for quick resolution and preventing bottlenecks in the deployment pipeline.
By incorporating automated testing throughout the development process, CI/CD ensures that code quality remains high. Developers can identify and fix issues early on, preventing bugs from reaching production and tainting the user experience. This results in more reliable and stable software.
Skilled software developers are in increasingly high demand, and that means you face stiff competition in convincing them to join your organization. And while high salaries and great benefits are always nice, what many developers want is to be a part of a great team. And there are many different metrics developers consider.
A working CI/CD methodology shows prospective hires that you are dedicated to supporting them, and that you have the right tools and processes in place to promote a better working experience with fewer development hurdles.
Effective communication and collaboration within large teams always has the potential to be difficult. This difficulty increases with the complexity of the task the team is attempting. Unfortunately, software development can be a very complex task.
CI/CD eliminates much of that complexity, automating many responsibilities and allowing developers to focus on their individual tasks. Continuous integration into a shared version-control repository helps ensure that as individuals within the team perform their assigned jobs, the overall structure and function of the app remains sound.
The continuous nature of CI/CD means more apps and application fixes, delivered more quickly. But CI/CD does not provide improved quantity at the expense of quality; automated tools constantly test new code changes, ensuring desired functionality before sending the changes to production or deployment.
Fault-detection and isolation tools pinpoint the root causes of any errors. Continuous-reliability tests focus on snapshots of code as they are introduced to the system. Non-critical defects are dealt with as they arise, reducing your team’s backlog. The result is an automated approach that allows developers to produce more-complete software solutions at lower cost and in less time.
Rapid and regular software updates mean that new features, enhancements, and bug fixes can be delivered to users faster, leading to a more satisfying user experience. Users appreciate software that evolves to meet their needs and resolve issues quickly. CI/CD enables organizations to respond to user feedback and changing market conditions, ensuring that their applications remain competitive and valuable.
The reliability and stability ensured by CI/CD likewise contribute to a smoother user experience. Automated testing and continuous monitoring help detect and address issues before they reach end-users, reducing the likelihood of downtime or performance problems.
This results in increased user trust and loyalty, as they can rely on the software to work as expected, benefiting the organization's reputation and customer retention.
Time to value (the duration it takes to deliver meaningful functionality to users) is a crucial metric for businesses. CI/CD excels in accelerating time to value by reducing development and deployment cycles. With the automation and efficiency brought by CI/CD practices, organizations can introduce new features and updates to users much faster than is possible with traditional development methods. This agility allows businesses to stay ahead of competitors, respond to market demands promptly, and seize opportunities as they arise.
The software development process can be demanding, and constant pressure to meet deadlines and resolve issues often leads to developer burnout. CI/CD helps alleviate this burden by streamlining and automating tasks that are time-consuming, repetitive, and prone to error. Developers can focus more on coding and problem-solving rather than spending endless hours on manual testing and deployment activities.
CI/CD equips teams with the resources to respond swiftly and effectively to incidents, improving mean time to resolution (MTTR) and minimizing possible impact on users and the business. CI/CD enables teams to simply revert to a previously stable version of the application, reducing downtime and customer frustration while the development team works to repair the current build.
CI/CD security involves integrating security measures into CI/CD pipelines to safeguard against vulnerabilities—typically through automated checks and testing to ensure that code changes are thoroughly vetted and comply with security standards before deployment. Incorporating security early in the development process (often referred to as ‘shifting left’) makes it easier to identify and mitigate risks, protect code from malicious attacks, prevent data leaks, and ensure overall quality assurance.
In a CI/CD pipeline, security challenges can arise from the rapid pace of development and deployment. Sensitive data may be unintentionally exposed. Unauthorized users may gain access to tools or data repositories. Insecure code or unverified third-party software components may introduce security weaknesses. Automated security checks—beginning with the planning and coding stages and continuing throughout the pipeline—identify vulnerabilities that might otherwise be overlooked, so that they can be addressed before the software moves into production.
CI/CD allows you to deliver code and applications at high velocity and virtually bug free. As such, CI/CD has become an integral part of many approaches, systems, and tools. One such example is how CI/CD works within the DevOps methodology of software development and delivery.
“DevOps” (a combination of the terms software development and technology operations) describes a practice in which roles such as IT, development, security, and quality engineering coordinate to produce a better end product and improved customer experience. DevOps is partially based on the Agile software-development methodology and is designed to shorten the development lifecycle and offer continuous delivery of high-quality software.
CI/CD is a natural complement to DevOps. CI/CD pipelines allow developers to push changes more quickly, while also ensuring application stability. Correctly implemented, CI/CD may have a major positive impact on DevOps KPIs, including deployment frequency, change lead time, and mean time to recovery from potentially damaging incidents.
Although the approach to CI/CD will be unique to specific organizations, projects, and tools, a typical CI/CD workflow may take the following steps:
Construct a CI/CD pipeline. This will need to cover the runnable specifications of every step the developers will need to take to deliver completed software solutions. A simplified CI/CD pipeline will likely include steps for sourcing, building, testing, and deploying software.
Automate the CI/CD pipeline. Connect the pipeline to your version control and source control systems. Incorporate workflow to automate the steps within the CI/CD pipeline.
CI/CD is a proven methodology, but that does not mean that every approach to CI/CD is totally effective. The success of your continuous integration, delivery, and deployment initiatives will likely depend heavily on the resources you choose to work with. There are many CI/CD tools available; before you commit to any specific solutions, be sure that they include the following features:
Integration with existing workflows
Ensure the tools can integrate seamlessly with your current development environment, including your version control systems, development platforms, and other DevOps tools.
Scalability
The tools should be able to handle the growth of your projects, supporting increasing numbers of builds, tests, and deployments without any loss of performance.
Ease of use and configuration
It’s important that CI/CD tools be user-friendly and easy to configure, as this will minimize the learning curve for your development team and allow for quick setup and integration.
Automation capabilities
Look for tools that offer powerful automation features, including automated testing, building, and deployment.
Security features
Faster deployment is not worth much if it leaves your applications vulnerable. Choose tools that include comprehensive security features, such as automated security testing and vulnerability scanning, to ensure your code remains secure throughout the entire development lifecycle.
Some of the most widely used CI/CD tools include:
Jenkins
An open-source CI server written in Java, Jenkins automates CI/CD steps and reporting. It supports a wide range of plugins for improved integration with various platforms and other tools.
- GitLab CI/CD
Part of the GitLab platform, this tool offers comprehensive CI/CD capabilities, including version control, issue tracking, and continuous integration and delivery.
- Travis CI
Travis CI is an open-source CI service used to build and test projects hosted on GitHub. It provides a simple way to set up CI/CD pipelines and integrates well with different languages and platforms.
- CircleCI
For a continuous integration and delivery platform that automates the build, test, and deployment process, consider CircleCI.
- Spinnaker
A multi-cloud continuous delivery platform designed to release software changes with high velocity and confidence, Spinnaker integrates well with Kubernetes for improved orchestration.
- GoCD
GoCD is a CI/CD server with an emphasis on modeling and visualization of deployment pipelines. It supports complex workflows and integrates with various tools and platforms.
- Tekton Pipelines
A CI/CD framework for Kubernetes platforms, Tekton provides a cloud-native CI/CD experience with containers, making it ideal for modern cloud-based applications.
- Screwdriver
Screwdriver is a build platform that is designed for continuous delivery and supports a range of integrations, alongside management and visualization features.
CI/CD has become indispensable, empowering organizations to deliver software quickly, reliably, and with the kinds of quality modern users expect. That said, being able to integrate various CI/CD tools and monitor and manage them from a central location is essential for maximizing efficiency and maintaining control over the software development process. This is why successful businesses are connecting their CI/CD initiatives to ServiceNow with ServiceNow DevOps Change Velocity.
Whether you're creating applications directly on the ServiceNow platform or using external tools like Azure, GitLab, or Jenkins, to build applications to run on other platforms, ServiceNow DevOps provides a seamless and powerful solution. Built on the award-winning Now Platform®, ServiceNow DevOps Change Velocity allows you to connect existing CI/CD pipelines and related tools to collaborate more effectively, manage code changes effortlessly, and gain a comprehensive view of your entire pipeline. Streamline your DevOps processes, automate change management, approvals, and deployments, and move from development to production faster and more efficiently than has ever been possible. And through it all, manage your value stream effectively, reporting on the entire pipeline, comparing performance across various tools, and identifying and resolving bottlenecks.