MiddleMedium2-4 hoursKubernetes

Use ConfigMap and Secret in Kubernetes

Inject non-sensitive and sensitive configuration into a Kubernetes workload using ConfigMap and Secret resources.

Kuberneteskubectl

Goal

Understand basic configuration management patterns for Kubernetes applications.

Skills You Practice

KubernetesConfigMapSecretPodsConfiguration

Architecture

Kubernetes ConfigMap

Kubernetes Secret

Deployment consuming environment variables

Pod receiving runtime configuration

Phases

Prepare configuration

Define which settings belong in ConfigMap and which belong in Secret.

Select non-sensitive config values

Select sensitive values

Create configuration plan

Create resources

Write or generate the ConfigMap and Secret objects.

Create ConfigMap manifest

Create Secret manifest

Reference both in Deployment

Deploy and validate

Apply resources and confirm the pod receives expected values.

Apply manifests

Check pod state

Inspect pod spec

Optionally exec into pod to verify env values

Core Steps

Create a ConfigMap.

Create a Secret.

Reference both in a Deployment.

Apply the resources.

Verify values inside the pod.

Verification

ConfigMap and Secret are created

Deployment starts successfully

Pod receives the expected environment configuration

README explains why ConfigMap and Secret are separated

Deliverables

ConfigMap YAML

Secret YAML

Updated Deployment YAML

README with validation steps

Interview Value

Very useful for explaining how application configuration is managed in Kubernetes and how sensitive data is handled differently.

Common Mistakes

Putting secrets into ConfigMap

Forgetting to reference keys correctly

Invalid base64 handling assumptions in Secret discussions

Not verifying values reached the pod

Next Upgrade

Mount ConfigMap as files

Use external secret management

Add Secret rotation discussion

Pair with an application that reads runtime config