LoopBack 4项目部署至CentOS 8 VPS遇模块缺失问题求助

Hey there, let's work through this LoopBack 4 deployment issue together. That MODULE_NOT_FOUND error for @loopback/boot is happening because you only copied your local dist folder to the server—you missed installing the project dependencies on the VPS. Here's a complete, step-by-step deployment guide tailored to your CentOS 8 setup:

1. Confirm Preconfigured Environment #

First, double-check the tools you mentioned are properly set up:

• Node.js: Ensure you're using an LTS version (16.x or 18.x recommended) that matches your local development environment. Run node -v to verify.
• MongoDB: Confirm the service is running with systemctl status mongod, and set it to start on boot with systemctl enable mongod.
• PM2 & Nginx: These should already be installed and functional as you noted.

2. Pull Source Code from Bitbucket #

Instead of transferring just the dist folder, pull the full project repository directly on the server to avoid environment mismatches:

1. Install Git if it's not already present:

   sudo dnf install git -y
   

2. Generate an SSH key for Bitbucket authentication (to avoid password prompts):

   ssh-keygen -t ed25519 -C "your-email@example.com"
   cat ~/.ssh/id_ed25519.pub
   

   Copy the output public key and add it to your Bitbucket account's SSH keys settings.
3. Clone your project to a suitable directory (e.g., /var/www):

   cd /var/www
   git clone git@bitbucket.org:your-username/your-billing-project.git
   cd your-billing-project
   

3. Install Project Dependencies #

This is the critical step you skipped earlier! LoopBack's core modules (like @loopback/boot) need to be installed on the server:

npm install

If you use Yarn locally, replace this with yarn install to keep consistency.

4. Compile the Project on the Server #

Compile the TypeScript source to JavaScript directly on the VPS to avoid cross-environment issues:

npm run build

This will generate the dist folder with your compiled application code.

5. Configure Environment Variables #

LoopBack relies on environment variables for database connections, port settings, and more. Create a .env file in your project root (copy your local .env and adjust for production):

NODE_ENV=production
DATABASE_URL=mongodb://localhost:27017/billing-db
PORT=3000

Ensure these values match your server's MongoDB setup and desired application port.

6. Start the App with PM2 #

Launch the compiled application using PM2, giving it a descriptive name for easy management:

pm2 start dist/index.js --name billing-service

• Check the app status: pm2 status
• View real-time logs: pm2 logs billing-service (use this to troubleshoot any remaining issues)

7. Set Up PM2 Auto-Start on Boot #

Make sure your app restarts automatically if the server reboots:

pm2 startup
pm2 save

pm2 startup creates a system service, and pm2 save saves your current PM2 process list.

8. Configure Nginx Reverse Proxy #

Route incoming HTTP traffic from your domain to the LoopBack app's port (3000 in this example):

1. Create a new Nginx config file, e.g., /etc/nginx/conf.d/billing.conf:

   server {
       listen 80;
       server_name your-domain.com;
   
       location / {
           proxy_pass http://localhost:3000;
           proxy_http_version 1.1;
           proxy_set_header Upgrade $http_upgrade;
           proxy_set_header Connection 'upgrade';
           proxy_set_header Host $host;
           proxy_cache_bypass $http_upgrade;
       }
   }
   

2. Test the Nginx configuration for errors:

   nginx -t
   

3. Restart Nginx to apply changes:

   systemctl restart nginx
   

9. Troubleshooting the Original Error #

If you still encounter MODULE_NOT_FOUND:

• Verify you ran npm install in the project root (check for a node_modules folder).
• Ensure your local and server Node.js versions match (version mismatches can break dependency installs).
• Try a clean dependency install:

  rm -rf node_modules package-lock.json
  npm install
  

内容的提问来源于stack exchange，提问作者Huan Ho