What Is Kubernetes?
Kubernetes (K8s) is an open source platform for managing microservice architectures and Linux Containers across public, private, and hybrid clouds. Most cloud providers support Kubernetes, including Amazon Web Services (AWS), Microsoft Azure, and Google Cloud.
Containers run on a shared operating system on top of host machines but remain isolated from each other unless connected manually. Kubernetes helps IT administrators, software developers, and DevOps engineers automatically deploy, maintain, scale, operate, and schedule application containers across many clusters of nodes.
CI/CD with Kubernetes
Containerization and Kubernetes are improving the consistency, speed, and agility of software projects. They offer a common declarative language for writing applications, operating jobs, and running distributed workloads.
In a Kubernetes environment, you create and apply a desired state in declarative YAML, Kubernetes parses it, and deploys resources in a cluster to achieve that desired state. For example, it can scale applications up or down, provision storage resources, and even add more physical machines (nodes) to a cluster via cloud platforms. Kubernetes handles the full lifecycle of applications, for example, healing application instances when their pod or container shuts down or malfunctions.
However, with all the power of Kubernetes, it still requires practicing the same continuous integration / continuous delivery (CI/CD) principles. You still need a robust CI system, which must be integrated with your container repository to automatically create new versions of container images. Within Kubernetes, you need automated tools that can help you establish a continuous delivery process. Most of these tools will be based on GitOps principles.
What is GitOps and How is it Used in Kubernetes?
GitOps is a way to achieve continuous deployment of cloud-native applications. It focuses on a developer-centric experience using tools that developers are already familiar with, such as Git version control repositories.
Triggering CI/CD pipelines with Git-based tasks has several benefits in terms of collaboration and ease of use. All pipeline changes and source code are stored in a unified source repository, allowing developers to review changes and eliminate bugs before deployment, and easily roll back in case of production issues.
Benefits of Kubernetes for Your CI/CD Pipeline
A CI/CD pipeline needs to ensure that application updates occur quickly and automatically. Kubernetes provides capabilities for automation and efficiency, helping solve various problems, including:
- Time to release cycles—manual testing and deployment processes can cause delays, pushing back the production timeline. A manual CI/CD process can result in code-merge collisions, extending the release time of patches and updates.
- Outages—a manual infrastructure management process requires teams to remain alert around the clock if a power outage or traffic spike occurs. If an application goes down, businesses can lose customers and money. Kubernetes automate updates and patches to provide a quick and efficient response.
- Server usage efficiency—applications that are not efficiently packed onto servers can incur overhead in capacity fees. It may happen whether the application runs on-premises or in the cloud. Kubernetes helps maximize the server usage efficiency to ensure capacity is balanced.
- Containerize code—Kubernetes enables you to run applications in containers deployed with all the necessary resources and libraries. Containerizing code makes applications portable between environments and easy to scale and replicate.
- Deployment orchestration—Kubernetes provides automation capabilities for managing and orchestrating containers. It can automate container deployment, monitor their health, and scale to meet changing demands.
The capabilities provided by Kubernetes help reduce the amount of time and effort required to deploy applications via a CI/CD pipeline. It provides an efficient model to monitor and control capacity demands and usage. Additionally, Kubernetes automates application management to reduce outages.
Related content: Read our guide to continuous deployment
Kubernetes CI/CD Best Practices
Containers Should Be Immutable
Docker allows you to rewrite tags when pushing containers. A common example is the latest tag. This is a risky approach because it represents a situation in which you may not know what code is running in the container.
A better approach is to ensure that all tags are immutable. You can associate a tag with a commit ID, a value that is unique and immutable in your codebase, to remove any doubt that the container is directly tied to the code from which it was created.
Leverage the Blue/Green Deployment Pattern
A CI/CD pipeline typically deploys code to production after passing certain tests and requirements. A robust CI/CD pipeline will usually result in successful deployments, but failed deployments do happen, and in some cases the application may deploy successfully but not fully satisfy end user requirements.
Therefore, a best practice is to use blue/green deployments, meaning that a new version of an application is deployed alongside the old version, switching over traffic to the new version, but keeping the old version active in case there is a need to roll back.
Learn more in our detailed guide to blue green deployment
Keep Secrets And Config Out Of Containers
Containers should never contain secrets or configurations, because they must be treated as immutable artifacts in the build process. Secrets should be stored as Kubernetes secrets or in a dedicated secrets vault, and settings should be stored in a ConfigMap of the Kubernetes cluster and mounted to a container. This lets you configure container deployments for each environment without changing the containers themselves.
Codefresh: The Kubernetes GitOps Platform
The Codefresh platform is a complete software supply chain to build, test, deliver, and manage software with integrations so teams can pick best-of-breed tools to support that supply chain. Codefresh unlocks the full enterprise potential of Argo Workflows, Argo CD, Argo Events, and Argo Rollouts and provides a control-plane for managing them at scale.
Codefresh provides the following key capabilities:
Single pane of glass for the entire software supply chain
You can easily deploy Codefresh onto a Kubernetes cluster, run one command to bootstrap it, and the entire configuration is written to Git. By integrating Argo Workflows and Events for running delivery pipelines, and Argo CD and Rollouts for GitOps deployments and progressive delivery, Codefresh provides a complete software lifecycle solution with simplified management that works at scale.
Built on GitOps for total traceability and reliable management
Codefresh is the only enterprise DevOps solution that operates completely with GitOps from the ground up. Using the CLI or GUI in Codefresh generally results in a Git commit. Whether that’s installing the platform, creating a pipeline, or deploying new software. The CLI/GUI simply acts as extended interfaces of version control. A change to the desired state of the software supply chain will automatically be applied to the actual state.
Simplified management that works at scale
Codefresh greatly simplifies the management and adoption of Argo. If you’ve already defined Argo workflows and events, they will work natively in Codefresh. Codefresh acts as a control plane across all your instances – rather than many instances of Argo being operated separately and maintained individually, the control plane allows all instances to be monitored and managed in concert.
Continuous delivery and progressive delivery made easy
Those familiar with Argo CD and Argo Workflows will see their configurations are fully compatible with Codefresh and can instantly gain value from its enterprise features. Those new to continuous delivery will find the setup straightforward and easy. The new unified UI brings the full value of Argo CD and Argo Rollouts into a single view so you no longer have to jump around between tools to understand what’s going on.
Conquer DevOps with Codefresh
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