WordPress with XDebug inside Docker

.env

# Debug state
DEBUG=true

# MySQL configuration
DB_USER=
DB_PASSWORD=
DB_NAME=
DB_HOST=db:3306

# WordPress configuration
WORDPRESS_DB_USER=$DB_USER
WORDPRESS_DB_PASSWORD=$DB_PASSWORD
WORDPRESS_DB_NAME=$DB_NAME
WORDPRESS_DB_HOST=$DB_HOST
WORDPRESS_TABLE_PREFIX=wp_
WP_PATH=$PWD/src/
XDEBUG_INI=$PWD/docker/xdebug.ini
THEME_NAME=
WP_DEBUG=$DEBUG
WP_DEBUG_LOG=$DEBUG
WP_DEBUG_DISPLAY=$DEBUG
CUSTOM_PLUGIN_1=
CUSTOM_PLUGIN_2=

# Docker configuration
WWW_PORT=12348
DB_PORT=12344
COMPOSE_PROJECT_NAME=
ORG=

# WPEngine configuration
WPE_DEV=
WPE_STAGE=
WPE_PROD=
WPE_SITE=$WPE_STAGE

# SSH configuration
SSH_KEY=

docker-compose.yml

version: "3.3"

services:
  db:
    image: mysql:5.7
    restart: always
    container_name: db.dev.${ORG}
    environment:
      - MYSQL_USER=${DB_USER}
      - MYSQL_PASSWORD=${DB_PASSWORD}
      - MYSQL_ROOT_PASSWORD=${DB_PASSWORD}
      - MYSQL_DATABASE=${DB_NAME}
    ports:
      - "${DB_PORT}:3306"

  www:
    user: "1000:1000"
    image: www.${ORG}:latest
    build:
      context: .
      dockerfile: wordpress.dockerfile
    restart: always
    container_name: www.dev.${ORG}
    environment:
      - WORDPRESS_DB_HOST=${DB_HOST}
      - WORDPRESS_DB_USER=${DB_USER}
      - WORDPRESS_DB_PASSWORD=${DB_PASSWORD}
      - WORDPRESS_DB_NAME=${DB_NAME}
      - WP_DEBUG=${WP_DEBUG}
    volumes:
      - ${WP_PATH}:/var/www/html/wp-content:rw
      - ${XDEBUG_INI}:/usr/local/etc/php/conf.d/xdebug.ini
    ports:
      - "${WWW_PORT}:80"

launch.json

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Listen for Xdebug",
      "type": "php",
      "request": "launch",
      "log": true,
      "port": 9003,
      "pathMappings": {
        "/var/www/html/wp-content": "${workspaceRoot}/src"
      },
      "externalConsole": false,
      "ignore": [
        "**/vendor/**/*.php"
      ]
    }
  ]
}

wordpress.dockerfile

FROM wordpress
RUN pecl install xdebug \
  && docker-php-ext-enable xdebug

xdebug.ini

zend_extension=xdebug.so
xdebug.client_host=host.docker.internal 
xdebug.client_port=9003
xdebug.discover_client_host=1
xdebug.log=/tmp/xdebug.log 
xdebug.mode=debug 
xdebug.start_with_request=yes