CDMS (Consortium-based Criminal Data Management System) - Backend

This document provides instructions for setting up and running the NestJS backend for the CDMS project.

This backend service provides REST APIs that interact with a Hyperledger Fabric blockchain for on-chain data and MinIO for off-chain encrypted file storage. The system is designed to connect law enforcement (Org1) and non - police (Org2) organizations.

Detailed Setup Guide: Refer to the complete step-by-step instructions in the PDF available here: [https://drive.google.com/file/d/1IL2ofHtzavJ69p9TSUYH7BD4KFO_O0vc/view?usp=drive_link]

Demo Video: Watch the setup and execution demo here: [https://drive.google.com/file/d/1B99f9jyfzrwNJm850XG8fRZxdl7kESn_/view?usp=sharing]

Note: All project code is located in the v2 branch.

Prerequisites

Before starting the backend, verify that the following external services are running and accessible:

• Hyperledger Fabric: The blockchain network must be running.
• Vault: The Vault server must be running and setup for transit (e.g., http://localhost:8200).
• MinIO: The MinIO server must be running and setup for storing (e.g., http://localhost:9001).

Setup and Configuration

1. Chaincode (Smart Contract)

Important: The chaincode (e.g., cdms.go) is not part of this backend. It must be deployed and instantiated on your Hyperledger Fabric network before starting the backend.

2. Environment Variables

Create a .env file in the root of the backend project with the following content:

# --- MinIO Configuration ---
MINIO_ENDPOINT=localhost
MINIO_PORT=9000
MINIO_ACCESS_KEY=<admin>
MINIO_SECRET_KEY=<password>
MINIO_USE_SSL=false
MINIO_BUCKET_NAME=<cdms-records>

# --- Vault Configuration ---
VAULT_ADDR=http://localhost:8200
VAULT_TOKEN=<token>

# --- Application Configuration ---
PORT=3000

3. Fabric Configuration

The backend requires connection profiles and admin certificates to communicate with the Fabric network.

1. Create a folder in the backend root named: fabric-config
2. Copy and rename the required files from your fabric-samples test network directory into this fabric-config folder.

Source Path (from fabric-samples)	Destination (in fabric-config)	Rename To
test-network/organizations/peerOrganizations/org1.example.com/users/[email protected]/msp/keystore/priv_sk	fabric-config/	key.pem
test-network/organizations/peerOrganizations/org1.example.com/users/[email protected]/msp/signcerts/[email protected]	fabric-config/	[email protected]
test-network/organizations/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls/ca.crt	fabric-config/	tls-root-cert.pem
test-network/organizations/peerOrganizations/org2.example.com/users/[email protected]/msp/keystore/priv_sk	fabric-config/	key-org2.pem
test-network/organizations/peerOrganizations/org2.example.com/users/[email protected]/msp/signcerts/[email protected]	fabric-config/	[email protected]
test-network/organizations/peerOrganizations/org2.example.com/peers/peer0.org2.example.com/tls/ca.crt	fabric-config/	tls-root-cert-org2.pem

4. Install Dependencies

Install the required Node.js packages.

npm install

Running the Application

Start the NestJS server in development mode.

npm run start:dev

The backend will be running at:

👉 http://localhost:3000