The CI/CD Process in a Cloud-Native World

The continuous integration and continuous deployment or delivery (CI/CD) process is a set of practices and tools used by software development teams to automate the building, testing and deployment of software. Here are the main components of this process:

• Continuous integration (CI): This is the practice of frequently merging code changes from multiple developers into a central repository, where the changes are automatically built, tested and verified. The goal of CI is to identify and fix bugs and conflicts early in the development cycle before they become more difficult and expensive to resolve.
• Continuous deployment or continuous delivery (CD): This is the practice of automatically deploying software to production or staging environments after the successful completion of the CI process. The goal of a CD/CD pipeline is to ensure that the software is always ready for release, with minimal risk and with the ability to quickly roll back changes if necessary. The main difference between continuous delivery and deployment is the level of automation, with deployment fully automating the process.

A central part of any CI/CD pipeline is a toolset that enables the automation of development processes such as code repositories, build servers and automation of software deployment. Learn more in this detailed blog post about the DevOps tools ecosystem.

How is CI/CD Changing in a Cloud-Native Environment?

Things are a bit different in a cloud-native environment, where applications are build using microservices and in containers on platforms like Kubernetes. CI/CD is changing in a cloud-native environment in several ways, including the following:

• Scalability: In a cloud-native environment, applications can be scaled horizontally, meaning that additional instances of an application can be created quickly and easily. This requires a CI/CD pipeline that can automatically scale up or down to support changes in application demand.
• Containerization: Cloud-native environments typically rely on containers, which enable applications to be deployed more easily and consistently across different environments. CI/CD pipelines in a cloud-native environment must be able to build and test containerized applications and integrate with container orchestration platforms such as Kubernetes.
• Infrastructure-as-code (IaC): In a cloud-native environment, infrastructure is managed using code rather than manually configuring servers and environments. This requires CI/CD pipelines to be able to deploy and manage infrastructure-as-code using tools such as Terraform or CloudFormation.
• Observability: In a cloud-native environment, applications are distributed across multiple containers and services, making it more difficult to identify and diagnose issues. CI/CD pipelines must integrate with observability tools such as Prometheus or Grafana to provide visibility into application performance and health.
• Microservices: Cloud-native applications are often built using a microservices architecture, which requires a CI/CD pipeline that can manage and deploy multiple independent services. This requires the ability to coordinate changes across multiple services and ensure that the entire system remains consistent and functional.

How Does CI/CD Work in a Kubernetes Cluster?

CI/CD in a Kubernetes cluster involves using Kubernetes and its associated tools to automate the building, testing, deployment and verification of software. The following is a brief overview of how CI/CD works in a Kubernetes cluster:

1. Build

The code is automatically built and compiled into an executable format. Developers commit their code changes to a version control system, such as Git. A CI tool, such as Jenkins, then pulls the code from the repository and builds a container image. The container image is stored in a container registry, such as Docker Hub, Google Container Registry or AWS Elastic Container Registry.

2. Test

Once the container image is built, it is deployed to a Kubernetes cluster for testing. Kubernetes creates a replica set of the container and deploys it to a test environment. Tests are then run against the container to verify its functionality and quality.

3. Deploy

The code is automatically deployed to a staging environment for further testing and validation. If the container passes all tests and meets quality criteria, it is deployed to a production environment. Kubernetes uses a deployment object to manage the deployment of the container to production. The deployment object ensures that the container is rolled out in a controlled manner, with zero downtime and the ability to roll back changes if necessary.

4. Verify

The software is monitored in production to identify issues and ensure it is performing as expected. Once the container is deployed to production, it is monitored and verified to ensure that it is performing as expected. Kubernetes provides built-in tools for monitoring and logging, such as Prometheus and Fluentd, which can be used to track the health and performance of the container in production.

4 Best Practices for Cloud-Native CI/CD

1. Leverage the Blue/Green Deployment Pattern

Blue/green deployment is a technique that involves maintaining two identical production environments (blue and green). One environment is active while the other is idle. The new release is first deployed to the idle environment and then switched over by updating the load balancer. This ensures that the new release can be rolled back quickly in case of any issues. This pattern helps to minimize downtime and reduce risk during deployment.

2. Implement Git-based Workflows (GitOps)

GitOps is a best practice for managing infrastructure and application deployments in Kubernetes. It involves using Git as a single source of truth for configuration, policy, and infrastructure. Changes to the environment are made through pull requests, which are reviewed and merged by other team members. GitOps enables teams to manage changes in a structured, auditable and scalable way.   

3. Containers Should Be Immutable

Immutable infrastructure is a principle where infrastructure is treated as code and is not changed after deployment. Containers should follow the same principle. Instead of updating a container, a new container should be built and deployed. This approach ensures that the environment is consistent and changes can be rolled back easily.

4. Pay Close Attention to Security

Security should be a priority in cloud-native CI/CD. It is essential to implement best practices such as scanning for vulnerabilities, enforcing policies and monitoring the environment for suspicious activity. Containers should be built from trusted sources and be scanned for vulnerabilities before deployment. Teams should also ensure that the environment is protected by implementing network security, access controls and monitoring.

Conclusion

In conclusion, the CI/CD process has become an essential part of modern software development, particularly in the context of cloud-native applications. As more organizations move to the cloud, the need for faster, more reliable and secure software releases has become more critical. The cloud-native approach to CI/CD involves leveraging containerization, automation and orchestration tools to build, test and deploy applications. 

The use of best practices such as blue/green deployment, GitOps, immutable infrastructure and security ensures that teams can deliver high-quality software quickly and consistently. With the right tools and processes in place, cloud-native CI/CD enables organizations to achieve faster time-to-market, higher quality and greater innovation.