Kubernetes is now the de-facto standard for container orchestration. With more and more organizations adopting Kubernetes, we must get our fundamental ops-infra in place before any migration. Kubernetes automates container deployments across various infrastructure environments and guarantees efficient resource utilization. Hence, companies should establish CI/CD pipelines that utilize the Kubernetes platform.
A CI/CD pipeline is a sequence of automated stages that software passes through, from code development to deployment in production.
Continuous Integration (CI) involves building and testing the application with each update. This practice helps detect errors early on and resolve them quickly by breaking down work into smaller increments. After successfully integrating and passing all tests, we can establish Continuous Delivery (CD) to automate the release and deployment process. Employing CI/CD in a project enables it to produce more dependable and frequent releases. CD refers to the software release pipeline and can stand for either 'Continuous Delivery' or 'Continuous Deployment' – two very similar practices, mainly different in their level of automation. The CD is about validating that the code provides the desired functionality by deploying it across a series of environments. These environments aim to replicate the actual production environment, where the software will eventually run, before deploying it in production.
Kubernetes CD pipeline makes more efficient and effective by more straightforward working methods of deploying and managing micro-services. Implementing good CD pipeline practices is key to establishing a security posture for production.
One of the main questions businesses adopting multi and hybrid clouds have is, can a hybrid cloud be a multi-cloud? The answer to this is Yes. When multiple public cloud service is combined with a private cloud, it becomes a hybrid cloud. It leads to a single IT solution between both clouds. For instance, an organization can build a private cloud for internal use and then create a hybrid cloud by merging this private cloud with a public cloud and then adding multiple other clouds depending on the various resources and services of the business. Similarly, a hybrid cloud can be created with one public cloud and consume the resources of other public clouds outside of the hybrid cloud environment. Thus, we can say that hybrid clouds and multi-clouds can coexist with their purpose.
Maintain secrecy : For CI/CD apps and services to function on the Kubernetes cluster, they need digital credentials to authenticate and authorize access. A CI/CD pipeline deployment can expose them through a source control system like GitHub. For maximum security and reliability, secrets should always be encrypted and kept outside containers.
Set up git-based workflows (gitops) : Utilizing Git-based operations to trigger CI/CD pipelines provides numerous advantages regarding collaboration and usability. By storing all pipeline modifications and source code in a unified source repository, developers can review changes and identify and rectify errors before deployment. Furthermore, including support for building snapshots and integration with chat tools like Slack offers assistance in monitoring and restoring changes during failures.
Implement a blue-green deployment strategy. : CI/CD pipelines typically deploy code to production after meeting the requirements for specific stages. Although, in most cases, CI/CD methodologies are correctly followed, and production deployment is executed seamlessly, there may be situations such as a security vulnerability or a resource outage that could result in the production instance malfunctioning. Therefore, it is considered a best practice to implement a blue-green deployment pattern that creates duplicate deployment instances alongside existing production instances, enabling easier switching in the event of failures or downtimes.
Scanning and testing images of containers : Incorporating the practice of testing and scanning container images every time a new idea is built is among the most valuable CI practices organizations can implement to identify potential vulnerabilities. Conducting tests on the container image guarantees that the commands within the container are functioning correctly and verifies that the content and specifications are accurate. Performing an image scan is critical to address any vulnerabilities from new builds pushed to the container registry.
Rollbacks : Incorporating rollback mechanisms is a crucial element to consider when developing a successful CI/CD pipeline. Rollbacks typically involve deploying previous releases to maintain the reliability and stability of the Kubernetes cluster within the production environment. Rollbacks allow reverting to a previous state or change during a disaster or code failure. Organizations can minimize the impact of any unexpected issues by having a well-defined rollback strategy and quickly restoring the system to a stable state.
Validation : A robust validation methodology, such as white or black box testing, is imperative to ensure stable builds without code quality issues when multiple builds are deployed simultaneously through continuous integration mechanisms. This framework seamlessly integrates code commits, automates the CI system, and minimizes the overhead of detecting failure areas.
Automated Testing : Automated testing is indispensable for streamlining the software delivery lifecycle in a continuous delivery (CD) pipeline. In the absence of an automated workflow, haphazard and unplanned testing can impede the efficiency of builds, thereby compromising code readability and maintainability in production.
Jenkins : Jenkins, originating from Java, is widely recognized as a prominent CI tool in the market. However, this discussion focuses on Jenkins X, a comprehensive CI/CD tool designed explicitly for Kubernetes. Jenkins X provides a highly opinionated approach to building and deploying Kubernetes applications. It can be extended with other CI/CD tools and cloud providers. Still, its current state of maturity does not warrant it being considered a reliable and stable CI/CD tool for managing Kubernetes clusters.
ArgoCD : Argo CD is a declarative continuous delivery tool designed specifically for Kubernetes. It fetches declarative application definitions from the source-code repository and builds and deploys them to the cluster. Argo CD implements the GitOps pattern and operates from the cluster side. As a result, unlike other tools, it is installed directly within the Kubernetes cluster. With an active community and widespread adoption, Argo CD is a compelling option for organizations seeking a tool with a GitOps mindset.
Spinnaker : Spinnaker is an open-source CD tool created by Netflix. Its primary focus is managing applications' infrastructure and deployment cycle, classifying it as a CD tool. Spinnaker features integration with multiple clouds, including Kubernetes and Cloud Foundry. Although highly sophisticated, it is a robust CD tool for larger organizations.
GitHub Actions : In the CI/CD Pipeline, GitHub Actions is the entity that automates the boring stuff. Think of it as a plugin bundling with every GitHub repository you create. The plugin exists on your repo to execute whatever task you tell it to. Usually, you'd specify what tasks the plugin should execute through a YAML configuration file.
GitLab CI : The GitLab CI service is a component of GitLab that builds and tests software automatically whenever a developer pushes code to the application. GitLab CD is another software service that deploys daily changes to the production environment. To speed up job execution, you can set up your runner (an application that processes builds) with all necessary dependencies preinstalled. The GitLab CI solutions are both cost-effective and secure. The costs can be adjusted according to the machine used to run it, making it highly flexible. With this tool, project team members can integrate their work daily, allowing for easy identification of integration errors through automated builds.
Kubernetes automation features can quickly patch updates, solve increases in hits in case of unforeseen or planned traffic spikes, and maximize the capacity of resource efficiency. As Kubernetes continues to gain popularity, mature CI/CD tool vendors are actively developing new features to integrate with it. When searching for a Kubernetes CI/CD pipeline tool, it is crucial to consider the deployment type (on-premises or cloud-based options), ease of use, and support for various operating systems.