🧩 DevOps Project: Deploying MongoDB & Mongo Express in Kubernetes

This project demonstrates how to deploy a web application (Mongo Express) and a database (MongoDB) on a Kubernetes cluster, using best DevOps practices such as ConfigMaps, Secrets, Deployments, and Services.

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📋 Project Overview

This setup showcases a classic two-tier application structure:

• MongoDB → backend database
• Mongo Express → web-based admin interface for MongoDB

🚀 Highlight:

• Deploy applications using Kubernetes manifests (.yaml files)
• Configure environment variables securely
• Manage internal and external connectivity between services
• Access applications from a browser

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🏗️ Architecture Diagram

Below is a visual representation of the project workflow:

Browser (HTTP Request: NodeIP:30000)
       |
       v
[ External Service (LoadBalancer): mongo-express-service ]
       |
       v
[ Mongo Express Pod (Deployment) ]
   |---> Reads DB URL from ConfigMap
   |---> Reads Credentials from Secret
       |
       v
[ Internal Service (ClusterIP): mongodb-service ]
       |
       v
[ MongoDB Pod (Deployment) ]

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⚙️ Components

1. MongoDB Deployment

• Creates a MongoDB Pod running the latest official mongo image.
• Exposes port 27017.
• Credentials (username/password) are not hardcoded but referenced from a Kubernetes Secret.

2. MongoDB Service (Internal)

• Type: ClusterIP
• Makes MongoDB accessible only within the cluster.
• Connects to Mongo Express through the service name.

3. Secret (mongodb-secret)

Stores MongoDB credentials securely.

4. ConfigMap (mongodb-configmap)

Contains the MongoDB service endpoint for Mongo Express to connect to.

5. Mongo Express Deployment

• Uses the mongo-express image.
• Exposes port 8081.
• Reads database URL from ConfigMap and credentials from Secret.

6. Mongo Express Service (External)

• Type: LoadBalancer
• Opens NodePort 30000, allowing browser access.
• Maps port 8081 (container) → 30000 (external).

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🧠 Request Flow

1. User sends HTTP request → NodeIP:30000
2. LoadBalancer service (mongo-express-service) forwards request to Mongo Express Pod
3. Mongo Express connects to internal service (mongodb-service)
4. Internal service routes request to MongoDB Pod
5. MongoDB authenticates using credentials from Secret

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🧰 Prerequisites

• Minikube
• kubectl
• Docker
• Visual Studio Code (optional for editing YAML files)

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🚀 Deployment Steps

1. Start your Kubernetes cluster

   minikube start --driver docker

2. Create the Secret

   kubectl apply -f mongo-secret.yaml

3. Create the ConfigMap

   kubectl apply -f mongo-configmap.yaml

   

4. Deploy MongoDB

   kubectl apply -f mongo.yaml

   

5. Deploy Mongo Express

   kubectl apply -f mongo-express.yaml

   

6. Check all resources

   kubectl get all

7. Access the application through Tunnel

   minikube service mongo-express-service

This will open Mongo Express in your default browser.

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🔍 Validation

To verify the setup:

kubectl logs mongo-express-68c7cbfbfd-zjv2z
kubectl describe service mongodb-service

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🧹 Cleanup

To remove all components:

kubectl delete -f .

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📊 Summary

Component	Type	Purpose
MongoDB Deployment	Pod	Database backend
MongoDB Service	ClusterIP	Internal DB access
Mongo Express Deployment	Pod	Web admin for MongoDB
Mongo Express Service	LoadBalancer	External access
ConfigMap	Key-Value Store	Stores MongoDB URL
Secret	Encrypted Data	Stores credentials

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🖼️ Visual Overview

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🧑‍💻 Author

Mohamed Eldemerdash
DevOps Engineer & Mechanical Engineer