Configmap
A ConfigMap is a Kubernetes API resource that stores non-confidential configuration data as key-value pairs for use by workloads and other cluster components.
Acing the Certified Kubernetes Administrator Exam, Second Edition
A ConfigMap is a Kubernetes API object that stores non-confidential configuration data for use by workloads or cluster components.
- How it is used
- Supplies pod configuration and holds kubelet and CoreDNS settings for cluster administration.
- How deep it goes
- Works through manifest generation, pod injection, and verification, then applies an edit-and-upgrade workflow to kubelet DNS configuration.
- Examples
- Uses a Redis configuration volume and a kubelet DNS-address change checked from a new pod.
- What you can do after
- Operate/configure it by creating and mounting a ConfigMap, or editing kubelet configuration and verifying a new pod's DNS settings.
Read how Acing the Certified Kubernetes Administrator Exam, Second Edition explains configmap →
Road to Kubernetes
A Kubernetes ConfigMap is a resource that stores non-sensitive configuration data as key-value pairs for use by workloads.
- How it is used
- Uses ConfigMaps to share container configuration through environment variables or read-only volumes without rebuilding images.
- How deep it goes
- Works through YAML data, volume declarations and mounts, and individual or whole-ConfigMap environment-variable references.
- Examples
- Demonstrates an NGINX index.html override and shared port and endpoint settings for Python and Node.js applications.
- What you can do after
- Build it from scratch: define a ConfigMap manifest and reference it from a Deployment as environment variables or a read-only volume.
Kubernetes in Action, Second Edition
A ConfigMap is a Kubernetes API resource that stores non-confidential configuration data for use by pods or other workloads.
- How it is used
- Separates application configuration from pod manifests so the same pod definition can be deployed with environment-specific values.
- How deep it goes
- Explains key–value storage, creation, environment-variable delivery, and configMap volumes, including missing-volume startup behavior.
- Examples
- Uses a status-message entry, kubectl creation commands, a YAML manifest, and a proxy configuration file mounted as a volume.
- What you can do after
- Apply it via kubectl and pod manifests to supply configuration through environment variables or mounted files.
Read how Kubernetes in Action, Second Edition explains configmap →
Google Anthos in Action
A ConfigMap is a Kubernetes resource that stores non-confidential configuration data separately from container images.
- How it is used
- Separates non-confidential application settings from container images so Pods can receive deployment-specific configuration.
- How deep it goes
- Explains the rationale and two consumption mechanisms, but does not provide manifests, commands, or update behavior.
- Examples
- Uses a location-specific web-server configuration shared across deployments through one portable container image.
- What you can do after
- Operate/configure Pods with deployment-specific settings without rebuilding application images.
Kubernetes for Developers
A ConfigMap is a Kubernetes object that stores non-confidential configuration data as key-value pairs or file contents.
- How it is used
- Supplies configuration files to Pods without requiring a custom container image.
- How deep it goes
- Works through direct file mounting and init-container selection of role-specific files, without detailing ConfigMap update behavior.
- Examples
- Uses Redis manifests with one configuration file, then primary and replica files selected by a Pod ordinal.
- What you can do after
- Operate/configure it by mounting Redis configuration in a StatefulSet and selecting role-specific files with an init container.
Machine Learning Platform Engineering
A Kubernetes ConfigMap is an API object that stores non-sensitive configuration data as key-value pairs for consumption by workloads.
- How it is used
- Separates non-sensitive deployment settings from workload definitions and configures Kubeflow notebook menus and scheduling choices.
- How deep it goes
- Defines manifests, inspection commands, pod references, and Kubeflow configuration, but does not explain ConfigMap storage internals.
- Examples
- Uses database settings, pod environment variables, notebook image menus, and node-affinity options as concrete configurations.
- What you can do after
- Operate/configure ConfigMaps with kubectl and inject selected keys into pods or Kubeflow notebook workflows.
Read how Machine Learning Platform Engineering explains configmap →
Learn Docker in a Month of Lunches, Second Edition
A ConfigMap is a Kubernetes API resource that stores non-sensitive configuration data as key-value pairs or text blocks.
- How it is used
- Provides application settings to Kubernetes containers through environment variables or mounted configuration files.
- How deep it goes
- Defines the resource and demonstrates both injection paths, while deferring broader configuration design and packaging.
- Examples
- Uses YAML manifests, kubectl inspection, environment-variable output, and a mounted JSON file.
- What you can do after
- Operate/configure containerized applications by injecting and verifying configuration with kubectl.
Read how Learn Docker in a Month of Lunches, Second Edition explains configmap →
Shipping Go: Develop, deliver, discuss, design, and go again
A configuration map is a Kubernetes resource that stores non-sensitive configuration values separately from the containers that consume them.
- How it is used
- Decouples Kubernetes configuration values from consuming containers when cluster-wide server environment variables or files are unsuitable.
- How deep it goes
- Defines a ConfigMap, creates it from YAML, and wires one key into a Deployment; defers sensitive values to Secrets.
- Examples
- Uses hello-api, database_url, redis-cluster, config.yml, and a Deployment environment-variable reference.
- What you can do after
- Apply via kubectl a YAML ConfigMap and reference its values from a Kubernetes Deployment.
Read how Shipping Go: Develop, deliver, discuss, design, and go again explains configmap →
Related concepts
- environment variableuses · An environment variable is a named value supplied through an operating-system or process environment and made available to programs for runtime configuration or information.
- Kubernetes resourcekind of · A Kubernetes resource is a persistent API-managed object representing the desired or observed state of a workload, configuration, or other cluster entity.
- Kubernetes Secretcontrasts with · A Kubernetes Secret is an API resource for storing sensitive data, such as credentials, tokens, keys, and certificates, and supplying it to workloads.
- cryptographic keyalternative to · A cryptographic key is a value supplied to a cryptographic algorithm to control operations such as encryption, decryption, signing, authentication, or verification.
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