Kubernetes, often shortened to K8s, is an open source platform for running and managing containerised applications across a group of machines called a cluster. Teams use it to deploy, scale and isolate software, and testers increasingly meet it when their applications, or their automated tests, run inside a Kubernetes cluster.
Why it matters: When the product under test runs on Kubernetes, the environment itself becomes a source of bugs. Resource limits, networking rules and the way containers share memory can all behave differently from a laptop or a local Docker setup. Tests that pass locally can fail in the cluster for reasons unrelated to the code under test.
In practice: Applications are packaged as container images and deployed into pods, the smallest units Kubernetes runs. Related resources are grouped into namespaces, often one per customer or environment. Test code can be packaged the same way and run as a Kubernetes job, a short-lived task that starts, runs the suite, reports results and is then discarded. Debugging usually means getting inside the pod, reading logs and copying files such as screenshots back to a local machine.
Examples:
- Running a UI test suite as a Kubernetes job in a customer's namespace just before and just after a major version upgrade.
- Keeping a debugging pod alive with a sleep command so a tester can run tests by hand and inspect what happens.
- Finding that headless Chrome fails to load iframes in a pod because of limited shared memory, then fixing it with a browser flag.
Common pitfalls:
- Assuming a test that works in Docker Desktop will behave the same way once deployed to the cluster.
- Treating cluster failures as flaky tests instead of investigating resource, network or configuration differences.
Do testers need to learn Kubernetes? Not in depth, but knowing how pods, namespaces and jobs work makes it far easier to run tests in the real environment and to tell product bugs from environment problems.
What does K8s stand for? K8s is a shorthand for Kubernetes, with the 8 standing for the eight letters between the K and the s.
