Effective CI/CD Pipelines for Kubernetes
Continuous integration/continuous delivery (CI/CD) pipelines are focused on building and delivering quicker and improved products by enabling automation and efficient collaboration. The approach of implementing CI/CD for cloud-native applications makes delivery cycles more robust while streamlining the development and deployment workflow.
This article discusses the key components of a Kubernetes CI/CD pipeline, along with recommended practices and tools you can use to make the pipeline more effective.
Key Components of a Kubernetes CI/CD Pipeline
The Kubernetes platform and CI/CD workflows both aim to improve software quality, as well as automate and boost development velocity. So it benefits companies to have CI/CD pipelines that leverage Kubernetes.
A few key components of a Kubernetes-based CI/CD pipeline include the following:
- Containers help achieve encapsulation of application components while enabling seamless integration through runtimes, such as Docker.
- Operating clusters deploy the containers for your software build once the CI/CD tool approves the containers.
- A version control system (VCS) is a unified source code repository that maintains code changes; this generates the trigger for a CI/CD tool to start the pipeline whenever any new change is pushed into its repository.
- Image registries store the Docker container images.
- Configuration management stores all details related to the infrastructure setup and identifies any newly introduced change in the system.
- Continuous monitoring and observability allows developers to obtain actionable insights and metrics by providing complete visibility into the application lifecycle.
- Security testing and audits maintain the equilibrium between rapid development and security of the application by ensuring the pipelines are free from potential security threats.
Considerations for an Effective CI/CD Pipeline
As implementing an effective CI/CD framework enables a sustainable model to streamline and accelerate production releases, CI/CD sits at the core of DevOps practice. A comprehensive understanding of a CI/CD pipeline workflow is fundamental to building an effective CI/CD pipeline, along with evaluating the enterprise requirement to help choose the right framework.
Below are some key considerations for making your pipeline effective:
- On-premises vs. managed vs. hybrid CI/CD: Each CI/CD pipeline type has its own effectiveness, depending on your requirements and infrastructure. Factors that determine the type of CI/CD pipeline you choose include ease of use, ease of set-up, infrastructure, and OS support.
- All-in-one CI/CD tool vs. case-specific solutions: Similar to the infrastructure setup, it is crucial to diligently assess the available CI/CD tools based on use cases, technical requirements, and organizational goals; some tools and their use cases are explained in the section below.
- Code testing and validation: An effective validation and automated testing framework is one of the core components of a CI/CD pipeline; this ensures a stable build with zero code quality issues while highlighting potential failure scenarios.
- Rollbacks: These help organizations redeploy the previous stable release of an application. Implementing a diligently planned rollback mechanism in CI/CD is vital to safeguarding the application in case of failure or security incidents.
Kubernetes CI/CD Approaches
There are two major paradigms for defining a Kubernetes-based CI/CD pipeline.
In a push-based pipeline, an external system, like a CI pipeline, generates build triggers to deploy the changes to the Kubernetes cluster following a commit to a version control system (VCS) repository. In such a model, Kubernetes cluster credentials are exposed outside the domain of the cluster.
In a pull-based pipeline, Kubernetes operators deploy the changes from inside of a cluster whenever new images are pushed to the registry.
Tools for Kubernetes CI/CD Pipelines
Drone CI is an open-source CI tool that works via a container-first approach and is built entirely on Docker. The plugins, components, and pipeline stages of Drone are deployed and executed as Docker containers. The platform offers a wide range of flexibility for using different tools and environments for the build, but you have to integrate it with Git Repository as the source repository to function.
Circle CI is a cloud-based CI tool that leverages an API to facilitate automatic Kubernetes deployments. It is intensely focused on testing the new commit before deploying via various methods like unit testing, integration testing, etc. Because of its features for implementing complex pipelines with configurations like caching and resource classes, it is one of the most popular lightweight integration tools for a Kubernetes ecosystem.
ArgoCD is a declarative GitOps continuous delivery tool that is a lightweight, easy to configure, and very performant tool purpose-built for Kubernetes. The platform considers Git as the source of truth, which enhances security, making access control and permission management easier to administer.
Spinnaker is an open-source continuous delivery tool that offers the flexibility of integrating with multiple cloud providers. As the platform does not rely on a GitOps model, config files can be stored within the cloud provider’s storage.
Collaboration and Issue Management Tools
Teams implement Jira for software collaboration, defect tracking, and work management. The tool offers customizable features like an intuitive dashboard, optimized workflows, efficient search, filtering, and defect management. Jira is purpose-built to support various use cases of project management, such as capturing requirements, test case management, and real-time tracking of tasks.
Zendesk is a cloud-based customer support platform that enables an organization to engage with its client through different collaboration channels, including phone, email, chat, and social media. Zendesk provides one easy-to-use platform for cross-functional collaboration and customer communications, thereby facilitating organizations to better manage customer queries and respond quickly.
Foresight is an observability platform for CI pipelines that enables secure, real-time monitoring of DevOps pipelines. Apart from being equipped with all observability techniques like utilizing metrics, traces, and logs, the platform also offers live debugging capabilities to facilitate quicker resolution of failures.
Prometheus/Grafana is an open-source event monitoring tool that implements a high-dimensional data model and stores metrics along with timestamps in a time-series database. Prometheus ships with a flexible query language and is one of the most popular alerting systems for complex Kubernetes clusters. Based on metrics generated by Prometheus, Grafana offers built-in visualization support for efficient querying and analysis.
Automation and Infrastructure Configuration Tools
Terraform by Hashicorp is an open-source infrastructure-as-code tool that facilitates DevOps teams’ ability to provision and manage infrastructure programmatically via configuration files.
Red Hat Ansible is an open-source automation platform that enables automation for provisioning, configuration management, and infrastructure deployment across cloud, virtual, and on-premises environments.
Open Policy Agent (OPA) is an open-source policy engine that supports a high-level declarative language that lets developers specify policy as code. The platform is built to impose granular-level policies on different components including CI/CD pipelines, microservices, Kubernetes clusters, etc.
Kube-bench is an open-source tool used to run the CIS Kubernetes Benchmark test on Kubernetes clusters; this ensures that the Kubernetes cluster is secure and deployed as per the security recommendations mentioned in the benchmark document.
All-in-One CI/CD Tools
Jenkins (including Jenkins X) is an open-source automation server that promotes CI and CD in varying levels of cluster complexity, enabling developers to automate application build, test, and deployment processes seamlessly across hybrid/multi-cloud setups. Jenkins X is an upgraded version of Jenkins that facilitates automated CI/CD for cloud-native containerized applications and orchestration tools like Kubernetes or Docker.
GitHub Actions is an open-source CI/CD tool by GitHub that supports an automated build, test, and deployment pipeline; it is a preferred CI/CD platform when the source code repository is GitHub.
GitLab CI/CD facilitates the continuous build, test, and deployment of software applications without the need for third-party integration.
Best Practices for Effective Kubernetes CI/CD Pipelines
Recommended practices for building an effective Kubernetes CI/CD pipeline include the following.
Avoid Hardcoding Secrets and Configurations into Containers
You should store configurations in configmap and should not hardcode them within the containers. This provides the flexibility of deploying the same container in different environments without making any environment-specific changes to it.
It’s also recommended to keep secrets out of containers and encrypt and store them within Kubernetes Secrets. This helps administer robust security by preventing credentials from getting exposed through a version control system in a CI/CD pipeline.
Use Helm for Deployments
To keep track of releases or logical groupings, you should implement the Helm package manager for managing Kubernetes application deployments.
Enable Git-Based Workflows
CI/CD pipelines should follow a GitOps methodology, allowing for all infrastructure configurations to be stored within Git. By leveraging GitOps, infrastructure code becomes more accessible to developers, letting them review the changes before they’re deployed.
Git also provides a unified source repository and snapshots of the cluster; this makes it easy for developers to refer to these when needed and also recover the application to the last stable state in the case of failure.
Utilize Canary/Blue-Green Deployment Patterns
Developers should leverage the Blue-Green deployment pattern that deploys an additional set of instances in parallel to the running production instances. This lets developers test the changes in the additional set of instances and switch over the traffic whenever testing is complete, eliminating the need for downtime during deployment.
Cache and Re-Use Container Images
It’s recommended to utilize the caching and re-use features of Docker container images to minimize container build times and reduce the risk of introducing defects in the newly built container image.
CI/CD sits at the core of modern application delivery because it offers agility, reduces the risk of open critical defects, and ensures enhanced software quality. While building an effective CI/CD pipeline is considered critical for rapid workflow execution, designing a CI/CD process is often a complex undertaking that requires diligent technical analysis, a generous amount of planning, and choosing the right set of tools.