Kubernetes (aka K8s) is the go-to container orchestration platform, providing auto-scaling, self-healing, storage, and more. Despite its capabilities and widespread usage, Kubernetes can be unwieldy for many. The fragmentation of add-ons can make for a lot of leaky abstractions, learning how to effectively use it can be daunting, and developers may find it unnecessarily complicated. But it’s clear that Kubernetes is here to stay and it’s imperative that DevOps teams and all conducting observability understand it.
What is Kubernetes?
Kubernetes is a popular way to automate, scale, and manage containerized applications. Originally developed at Google and called “Borg,” Kuberetes is built on over a decade of containerized workloads at Google. In 2014, it was open sourced and is now maintained by the Cloud Native Computing Foundation (CNFC) continuing to go through the contributions of its large community.
Kubernetes makes it possible to deploy applications across multiple hosts while letting teams manage them as a single logical unit. It abstracts the underlying infrastructure and provides a uniform API for interacting with clusters. Its automation spans container deployment, scaling, and monitoring, as well as self-healing mechanisms to ensure applications are always up and running.
Additionally, Kubernetes supports a wide range of container runtimes, including Docker, containerd, and CRI-O. Its versatility and scope has made it the standard for production environments.
What are containers?
Containers enable developers to package and deploy applications with all dependencies and configurations bundled together with configuration files and libraries, dependencies, and all the other elements required to run them. Containers are lightweight, standalone, and executable consistently across different computing environments from a laptop to a production environment, making them the ideal technology in today’s modern architecture. By isolating apps from each other and the underlying infrastructure, containers ensures consistency even with dynamic, cloud-native applications.
Kubernetes vs. Docker?
Although they may seem like competing technologies, they are complementary. While Docker lets you put everything into one container that can be stored and opened whenever and wherever it’s required, Kubernetes is still needed to orchestrate and manage them. Docker does not directly compete and Kubernetes is needed to manage and run containers at scale. The difference really lies in each technology’s role in modern application development.
What does Kubernetes do?
Automating the deployment, scaling, and management of containerized applications means that developers can focus on writing code instead of managing the underlying infrastructure. Kubernetes manages the lifecycle of containers, and provides features for everything from load balancing to rolling updates to uptime. More specifically, Kubernetes is behind:
- Scalability: Scaling is easy with automated deployment and scaling
- Portability: A standard interface makes it simple to deploy and manage containerized applications across environments, whether on-prem, in a public cloud, or in multicloud environments.
- Resilience: Kubernetes’ self-healing capabilities can detect and act on failure of underlying infrastructure or applications for better performance and uptime.
- Agility: The continuous and effective delivery of applications is possible because of the automation Kubernetes offers. It simplifies continuous integration and deliver (CI/CD).
- Cost efficiencies: Kubernetes offers cost savings by enabling efficient use of resources through built-in monitoring and optimization.
What are the challenges of Kubernetes?
While Kubernetes can be a boon to any organization. It comes with its challenges due its complex architecture and many moving parts. Some these challenges include:
- Complexity: Kubernetes has a steep learning curve due to its many discrete parts. Just setting up a cluster requires knowledge of and configuring multiple components like etcd, API server, kubelet, and kube-proxy. Then there’s scheduling, scaling, and networking.
- Scalability: Kubernetes is meant to scale applications easily, but managing such deployments can be a pain. A team managing a large e-commerce platform with millions of users must make sure their Kubernetes cluster can handle the workload.
- Security: Kubernetes has security features like role-based access control, policies, and container security features. But configuring them and keeping up with the latest threats and vulnerabilities can be a lot when trying to secure a Kubernetes deployment.
- Networking: Planning and configuration must be thoughtful and thorough. When improperly done, Kubernetes can become cumbersome across clouds and infrastructure — not to mention communication at the containers and services layers.
- Managing Stateful Applications: Designed for stateless applications, Kubernetes can make managing stateful applications challenging, especially when dealing with things like configuring persistent volumes, data backups, and stateful sets.
- Observability: Kubernetes offers a rich set of metrics, logs, and events data. It can be overwhelming and too much to monitor with traditional tools and services.
What are the benefits of Kubernetes?
Kubernetes has matured into a versatile open-source platform that offers developers and DevOps teams a slew of benefits including:
Faster time to market
Kubernetes allows for rapid deployment of applications, reducing the time it takes to get new features and functionalities into production. When developer time is at a premium, nothing beats being able to create and manage containers that contain everything an application needs to run across any environment and at speed.
Increased developer productivity
In the same vein, Kubernetes’ flexibility, self-healing, and automation means developers can focus on writing code and optimizing application functionality instead of splitting their time with monitoring, troubleshooting, or management.
Portability
Kubernetes offers a consistent platform for deploying and running applications across environments ranging from laptops to multicloud infrastructures. This helps reduce the time and effort required for application deployment and maintenance. It also helps avoid vendor lock-in, helping organizations grow their offerings without needing to re-architect their architecture.
Improved reliability
Users expect digital experiences to be available around the clock. Kubernetes’ built-in features enable high availability and self-healing, which means minimized downtime and a resilient application for consistent user experiences.
What are Kubernetes best practices?
Keep Immutable Infrastructure in Mind
When using Kubernetes, applications are deployed as containers that are immutable and stateless. As such, any change to an application should use a new container image, rather than updates to the existing container. Additionally, the containers used in staging, development, and QA should be the same as the one deployed into production to avoid any changes that may happen between testing and launch.
Use Labels and Annotations
Labels and annotations are key-value pairs that can be added to Kubernetes resources to provide metadata that can be used to identify resources, enable services discovery, and monitoring and tracing. Doing this consistently will help with efficient management of resources. It helps recognize the attributes of a particular resource, and let’s you filter and select objects via kubectl.
Namespaces and Simplified Management
Namespaces makes it possible to group related resources within a given cluster. They can be used to create logical separation between teams or applications, provide access control, and resource management. In short, teams can enable separate teams to work simultaneously within the same cluster without overwriting or getting in the way of each group’s project.
Take Advantage of Autoscaling
Horizontal pod autoscaling (HPA) allows teams to scale the number of pod replicas based on resources use or other custom metrics, ensuring that an application is always available white maintaining efficient use of resources. Other scaling options include vertical pod and cluster autoscaler.
Use ConfigMaps and Secrets
Teams should store configuration data and other sensitive data separately from the application code to ensure that the configuration data and secrets can be managed independently and shared across different environments. Secret vault services are great for this, exposing passwords, access keys, and other sensitive information on an as-needed basis.
Leverage GitOps Workflows
GitOps is a Git-based workflow that automates tasks like CI/CD pipelines. The development method uses Git as the source of truth, and any changes to infrastructure and application code is made via pull requests to a Git repository that automatically deploys the changes. It improves collaboration, version control, auditability, consistency, and security.
How will Kubernetes continue to affect DevOps and observability?
There is no doubt that Kubernetes’ adoption will continue to grow, leading to more and more organizations adopting DevOps and the principles of CI/CD. This will mean more iteration and automation in the management and build process for new infrastructure and applications, in turn, spurring further development around security and observability. While Kubernetes and third-party service providers have continued to bolster security for containerized applications, there is still room for improvement. The same goes for observability despite existing tools like Prometheus and Grafana. For instance, teams will likely soon start using machine learning and AI-powered monitoring and troubleshooting. Additionally, there will be a greater need for advanced management and observability tools that can operate across on-prem and cloud-based services and environments.
