Help with apache+php+mySql+node

Hi, I am new to Docker and right now I building my first app using PHP+APACHE+MYSQL.

I want to add node_modules to the project and kind of lost my way with the process.

Right now I have this Dockerfile -

FROM php:7-apache
RUN apt-get update -y && apt-get install -y libpng-dev && apt-get install -y libcurl4-openssl-dev
RUN docker-php-ext-install pdo pdo_mysql gd curl
RUN a2enmod rewrite
RUN service apache2 restart

And this docker-compose.yml

version: ‘2’

services:
webserver:
build: ./docker/webserver
image: myimage
ports:
- “80:80”
- "443:443"
volumes:
- /Users/username/Sites:/var/www/html
links:
- db

db:
image: mysql:5.7
ports:
- "3306:3306"
volumes:
- ./db:/var/lib/mysql
environment:
- MYSQL_ROOT_PASSWORD=password
- MYSQL_DATABASE=dbname

My question is, what and where do I need to configure to make everything work together?
Thank you!

looks already quite okay.
did you configure your Apache/PHP that the mysql database is reachable under name “db”?