🚀 Kubernetes ConfigMap & Secret Lab

Hands-on Kubernetes lab focused on ConfigMap, Secret, and Deployment configuration management.

This project demonstrates how to manage application configuration and sensitive data in Kubernetes using best practices.

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🏗️ Architecture Diagram

Architecture Overview

The application demonstrates how configuration and secrets flow into containers in Kubernetes.

User ⬇ Kubernetes Cluster ⬇ Deployment (3 Pods) ⬇ ConfigMap + Secret ⬇ Application Containers

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📦 Technologies Used

• Kubernetes
• ConfigMap
• Secret
• Deployment
• BusyBox (test container)
• kubectl CLI

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📂 Project Structure

k8s-configmap-secret-lab
│
├── 02-configmap-as-envvars.yaml
├── 03-configmap-selective-env.yaml
├── 06-secret-as-envvars.yaml
├── 08-combined-cm-and-secret.yaml
├── 09-deployment-with-config.yaml
│
├── docs
│   └── architecture.png
│
└── README.md

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⚙️ Lab Tasks

1️⃣ Create ConfigMap

Create configuration values for the application.

Example:

APP_ENV=production
APP_PORT=8080
APP_COLOR=blue
MAX_CONNECTIONS=100

Command:

kubectl create configmap app-config \
--from-literal=APP_ENV=production \
--from-literal=APP_PORT=8080 \
--from-literal=APP_COLOR=blue \
--from-literal=MAX_CONNECTIONS=100

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2️⃣ Inject ConfigMap into Pod

Apply:

kubectl apply -f 02-configmap-as-envvars.yaml

Verify:

kubectl logs env-pod

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3️⃣ Inject Specific ConfigMap Keys

Apply:

kubectl apply -f 03-configmap-selective-env.yaml

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4️⃣ Create Kubernetes Secret

kubectl create secret generic db-secret \
--from-literal=DB_USER=admin \
--from-literal=DB_PASSWORD=p@ssw0rd123 \
--from-literal=DB_NAME=myapp

Verify:

kubectl get secret

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5️⃣ Inject Secret into Pod

kubectl apply -f 06-secret-as-envvars.yaml

Verify:

kubectl logs db-pod

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6️⃣ Combine ConfigMap + Secret

kubectl apply -f 08-combined-cm-and-secret.yaml

Verify environment variables:

kubectl exec -it fullapp-pod -- env

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7️⃣ Deployment with ConfigMap + Secret

Create deployment with 3 replicas:

kubectl apply -f 09-deployment-with-config.yaml

Verify pods:

kubectl get pods

Check environment variables:

kubectl exec -it <pod-name> -- env

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🔐 ConfigMap vs Secret

Feature	ConfigMap	Secret
Purpose	Non-sensitive configuration	Sensitive data
Examples	Ports, environment names	Passwords, API keys
Encoding	Plain text	Base64 encoded

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🧠 Key Learning Points

• How to externalize configuration in Kubernetes
• Securely manage sensitive information
• Inject configuration into containers
• Use ConfigMap and Secret with Deployments
• Maintain consistent configuration across multiple pods

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📚 Author

Ahmed Sabra DevOps Trainee — Digilians DevOps Intensive Program

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⭐ If you like this project

Give the repository a Star ⭐ on GitHub.

ConfigMap-Lab