Kubernetes - Labels & Selectors

Kubernetes is an open-source platform for automating the deployment, scaling, and management of containerized applications, created by Google and later donated to CNCF. Labels and Selectors play a vital role in organizing and interlinking Kubernetes objects like pods, deployments, and services. Labels are key-value pairs assigned to pods via deployments, while Selectors match these labels to connect services with the respective pods. Labels can be added or modified during or after pod creation using commands like kubectl label pod. They are case-sensitive, with a maximum length of 63 characters, and follow specific syntax and rules, including Equality-Based and Set-Based Selectors for matching.

Effective label usage includes meaningful naming, consistency, uniqueness, and organizing or scaling resources within a cluster. For example, using labels like myapp: prod-environment can represent a pod's purpose clearly. To update labels, the CLI command kubectl label pods is preferred over directly editing YAML files. Labels differ from annotations, as the latter store metadata without influencing pod scheduling or identification. 

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