Configuration with ConfigMaps

A ConfigMap stores non-confidential configuration as key-value pairs, decoupling environment-specific settings from container images so applications stay portable. Pods consume ConfigMaps as environment variables, command-line arguments, or files in a volume, and the Pod must be in the same namespace as the ConfigMap. ConfigMaps provide no secrecy or encryption — use a Secret for confidential data. The data and binaryData fields hold UTF-8 strings and base64-encoded binary data respectively, and their keys must not overlap; the ConfigMap name must be a valid DNS subdomain name, stored data cannot exceed 1 MiB, and setting the immutable field creates an immutable ConfigMap whose contents can no longer be mutated. Koskamo editorial guidance: mark ConfigMaps immutable when their contents never change, so accidental edits surface as errors instead of silent drift. Scope: Kubernetes. Reviewed October 4, 2026.