MongoDB on AWS EKS Cluster

Overview

This project automates the deployment of MongoDB on an AWS EKS cluster. By utilizing Terraform for infrastructure provisioning and Ansible for configuration management, we've streamlined the process to ensure a smooth and efficient deployment. Once set up, users can access the MongoDB instance either through the mongosh shell from a bastion instance or programmatically via the pymongo Python library.

Prerequisites

• AWS Account
• Terraform installed
• Ansible installed
• Access to AWS S3 bucket for Terraform state management

Setup Instructions

1. Infrastructure Setup

• Modify Bucket Names

Edit the bucket names specified in main.tf and variables.tf to fit your desired AWS environment.

• Initialize Terraform:

Navigate to the project's root directory and run: terraform init

• Apply Terraform Configuration

Deploy the AWS resources: ./apply_infrastructure.sh

Applying infrafstructure using the script also forwards port to localhost that allows DB client connection.

• Retrieve Bastion Host IP

Once Terraform has finished provisioning the resources, get the public IP of the bastion instance: terraform output bastion_public_ip

• Accessing Key Pair

Terraform script will create a key pair and save the private key as mongodb-in-eks.pem in the current directory. Ensure you keep this key secure.

2. Accessing MongoDB

• Via mongosh

  • SSH into the bastion host: ssh -i mongodb-in-eks.pem ec2-user@$(terraform output bastion_public_ip)

  • Extract the MongoDB root password: password=$(kubectl get secret mongodb -o jsonpath='{.data.mongodb-root-password}' | base64 --decode)

  • Access the MongoDB instance using the extracted password: mongosh --host localhost --port 27017 --username root --password $password --authenticationDatabase admin

• Via pymongo

Make sure your Python script is equipped with the get_mongodb_password function to pull the root password from Kubernetes secret:

from pymongo import MongoClient
from kubernetes import client, config
import base64

def get_mongodb_password():
    config.load_kube_config()
    v1 = client.CoreV1Api()
    secret = v1.read_namespaced_secret(name="mongodb", namespace="default")
    encoded_password = secret.data["mongodb-root-password"]
    decoded_password = base64.b64decode(encoded_password).decode('utf-8')
    client.ApiClient().close()
    return decoded_password

Use the extracted password to establish a connection:

password = get_mongodb_password()
mongo_client = MongoClient('localhost', 27017,
                          username='root',
                          password=password,
                          authSource='admin')
db = mongo_client[<dbname>]

• Via DB Client such as Studio 3T

MongoDB password is additional saved in AWS secretmanager and can be retrieved using the following AWS CLI command:

aws secretsmanager get-secret-value --secret-id MongoDBPassword --region <region> | jq -r .SecretString

The script for applyting terraform script also does port-forwarding to allow connection to localhost. You can use the following URL to connect to the MongoDB server:

mongodb://<credentials>@localhost:27017/?directConnection=true&serverSelectionTimeoutMS=2000&authSource=admin&appName=mongosh+1.10.5

3. Destroy infrastructure

Destroy the AWS resources: ./destroy_infrastructure.sh

Conclusion

This automated setup aids in deploying a MongoDB instance on an AWS EKS cluster efficiently. The integration of Terraform and Ansible ensures that infrastructure and configuration management are handled seamlessly.