This is the first in a multi-part series dedicated to explaining the "what", “why” and “how” to use CI/CD.
Series
- Part 01: The path to CI/CD Mastery (this one)
- Part 02: The CI/CD automation on GitHub
- Part 03: Building an advanced Github Worklfow
CI/CD streamlines the processes of building, testing, and deploying your code, enabling faster and more dependable delivery of code changes.
Automation plays a key role in the success of DevOps, with CI/CD being an essential element. CI/CD encompasses continuous integration and continuous delivery or deployment, collectively forming a “CI/CD pipeline.” This pipeline is a sequence of automated workflows that assist DevOps teams in reducing manual work.
Ci/CD Pipeline
Before the adoption of CI/CD
Before the adoption of Continuous Integration (CI) and Continuous Deployment/Delivery (CD), software development processes were often slow, manual, and prone to errors.
Here's a glimpse into the typical workflow and challenges faced.
Manual Integration
Developers worked in isolation on separate branches or copies of the codebase. Integration happened infrequently, often only at the end of the development cycle. This led to “integration hell,” where merging changes from multiple developers was time-consuming and error-prone.
Delayed Testing
Testing was usually done manually and only after the code was fully developed. This delayed the detection of bugs and issues, often leading to significant rework and delays in the project timeline.
Infrequent Releases
Software releases were infrequent and involved a lot of manual effort. The deployment process was often complex, risky, and required extensive coordination between development and operations teams. This resulted in longer release cycles and slower delivery of new features to customers.
Lack of Feedback
Developers often didn't receive feedback until the end of the development cycle, making it difficult to address issues in a timely manner.
High Risk of Failure
The lack of automated testing and deployment increased the risk of failures during integration and deployment. Rolling back changes or fixing issues in production was challenging and time-consuming.
Introducing CI/CD
The CI/CD transformed the software development process, introducing automation, efficiency, and reliability.
Developers must be able to deploy code on their first day. Here's how CI/CD improved the workflow.
Frequent Integration
CI/CD pipelines automatically integrate code changes from multiple developers frequently, often multiple times a day. This continuous merging helps detect integration issues early, reducing the complexity of merging code.
Automated Testing
Automated tests are an integral part of CI/CD pipelines. Every code change triggers a series of tests that run automatically, ensuring that new changes do not break existing functionality. This leads to faster detection and resolution of bugs.
Continuous Deployment/Delivery
With CD, code changes are automatically deployed to production or staging environments after passing automated tests. This enables frequent and reliable releases, allowing new features and bug fixes to reach customers quickly.
Early Feedback
CI/CD provides immediate feedback on code quality, performance, and functionality. Developers can quickly identify and address issues, leading to faster iterations and improvements.
Reduced Risk
Automation in testing and deployment reduces the risk of human error and deployment failures. Rollbacks and hotfixes can be implemented swiftly, minimizing downtime and ensuring a stable production environment.
Improved Collaboration
CI/CD fosters better collaboration between development, testing, and operations teams. The automated workflow and shared responsibility for code quality create a culture of collaboration and accountability.
Enhanced Agility
Organizations can respond quickly to changing market demands and customer feedback. The ability to deliver updates rapidly and reliably allows businesses to stay competitive and meet customer expectations.
Continuous integration (CI)
Continuous integration (CI) involves frequently and automatically merging code changes from multiple developers into a shared repository.
The main features of continuous integration pipelines include:
- Automatic builds and tests: CI tools automatically build and test new code to identify conflicts or errors. When issues are detected, developers are notified early on, allowing them to resolve problems before they escalate into more complex and costly challenges later in the development cycle.
- Early Feedbacks: Continuous integration provides immediate feedback on the health and quality of the application after each change. This enables teams to make informed decisions, quickly iterate on their code, and proactively address issues, leading to more reliable, resilient, and customer-focused software products.
Continuous integration promotes a culture of agility, helping organizations optimize their development processes, reduce waste, and quickly adapt to changing market conditions.
Continuous delivery (CD)
Continuous delivery (CD) extends the CI process by ensuring code is always in a deployable state, allowing teams to release software at any time with confidence. Continuous delivery is often confused with continuous deployment, but there is a crucial distinction. A continuous delivery pipeline features:
- Manual deployments: After successful testing, the release is packaged and staged, awaiting manual approval for deployment. A scripted deployment process may be in place, but it will not start until deployment is triggered by a designated approver.
- Deploy-ready code: In continuous delivery, the code is always maintained in a state where it's ready for deployment to production, but the actual deployment is triggered manually, providing a final checkpoint for human oversight and control before changes are released into the live environment.
Continuous Delivery PipelineContinuous delivery enhances collaboration between development and operations teams and reinforces confidence in the delivery process through heightened visibility and control.
Continuous deployment (CD)
Continuous deployment (CD) automates the entire software release process, from code integration and testing to deploying changes into the production environment. Unlike continuous delivery, continuous deployment requires no human intervention. A continuous deployment pipeline features:
- Automatic deployments: Once the code passes all tests, it is automatically and immediately deployed to the production environment without manual approval.
- Frictionless releases: Continuous deployment enables organizations to release software updates to customers as soon as they have been validated, reducing time to market.
Continuous Deployment PipelineContinuous deployment removes inefficient manual tasks from the delivery life cycle, accelerating time to market and creating a continuous flow of value to end users.
Conclusion
Implementing CI/CD the right way vastly improved our ability to deploy code safely and easily.
Along the way, there are several reasons to adopt CI/CD:
- Aim to minimize manual coordination efforts.
- Enable developers to experiment freely without the fear of disrupting others' work.
- Choose a robust build artifact format that suits your requirements.
- Implement automated tests to boost confidence in each release and cut down on manual tasks.
- Identify issues early.
- Automate deployment processes.
- Centralize monitoring and, if possible, avoid managing the monitoring infrastructure/tools yourself.
