How to generate a production build of an API done with NESTJS

Question

I am generating the production version of an API I made using the NESTJS framework and would like to know which files I should upload to the server. When I run the "npm run start: prod" compile it generates the "dist" folder but I tried to run only with it but it is not enough to run my application. Do I need to upload all files to the server? I did several tests removing the folders I used during development but only managed to run in production mode when I was all the same in dev mode.

I looked in the documentation for something about this but found nothing. can anybody help me?

Thank you

Answer 1

Honestly, you should only really need the dist folder as that's the JS 'complied' files. To run your application, commonly you'd use this command node dist/main.js. As to what files you upload it's up to you. Me personally, I use a lot of continuous integration so I would just clone to repo into my container/server and use yarn start:prod. This is so everytime I deploy I'm generating the required files to run in a production environment.

Like @Kim Kern mentioned, some node modules are native built using node-gyro; so it's also always best to build your node_modules on the server/container when deploying. Your deployment script should look something like this

git clone [email protected]:myuser/myrepo.git /var/www/
cd /var/www/
node -v && \
yarn && \
yarn build && \
yarn start:prod

The above script should

1) pull the required repo into a 'hosted' directory
2) check the node version
3) install node_modules and build native scripts etc
4) build the production distribution
5) run the production JS scripts

If you look in your package.json file you'll notice the different scripts that are run when you use yarn start, yarn start:dev and yarn start:prod. When in dev you'll notice the use of ts-node which is a typescript node runner type thing (can't remember the correct phrase). Also the start:dev script uses nodemode to restart the ts-node script. You'll also see the start:prod script uses node dist/main.js and that the prestart:prod script runs rm -rf dist && tsc which removes the dist folder and 'compiles' the javascript required for a production environment.

However, the drawback of a typescript application on your server without continuous integration is that there is the possibility of typescript compilation errors which you wouldn't see or know about until running the prod scripts. I would recommend putting a procedure in place to compile the javascipt from typescript before making a deployment as you don't want to delete the current dist build before knowing the next release will build and run!