fix this thing, but db error on startup

docker/Dockerfile

@@ -0,0 +1,44 @@
+# Dockerfile for the laravel.io application
+
+FROM ubuntu:22.04
+
+ARG SEED_DATA="false"
+
+RUN apt update
+# install system dependencies
+RUN apt install software-properties-common git -y
+
+RUN git clone https://github.com/laravelio/laravel.io.git /app/laravel
+
+WORKDIR /app/laravel
+
+RUN mv .env.example .env
+
+# add php apt repo
+RUN add-apt-repository ppa:ondrej/php
+
+RUN apt update
+
+# install app dependencies
+RUN DEBIAN_FRONTEND=noninteractive TZ=Europe/Lisbon apt install php8.2 php8.2-simplexml php8.2-curl php8.2-dom composer npm -y
+
+ENV DB_CONNECTION=mysql 
+ENV DB_HOST=laraveldb 
+ENV DB_DATABASE=laravel
+ENV DB_USERNAME=myuser
+ENV DB_PASSWORD=password
+
+RUN composer install
+
+RUN php artisan key:generate
+
+# seed data if build arg is provided
+RUN if [ "$SEED_DATA" = true ]; then php artisan migrate --seed; fi
+
+EXPOSE 8000
+
+RUN npm install
+RUN npm run build
+
+#Open on port 8000 to all addresses
+ENTRYPOINT php artisan serve --port=8000 --host=0.0.0.0