Build backend in docker for production with env vars

backend/Dockerfile

@@ -0,0 +1,23 @@
+FROM node:14 as build-deps
+
+WORKDIR /usr/src/app
+COPY package*.json ./
+RUN npm install
+
+COPY . .
+RUN npm run build
+
+RUN apt-get update && apt-get install -y wget
+ENV DOCKERIZE_VERSION v0.6.1
+RUN wget https://github.com/jwilder/dockerize/releases/download/$DOCKERIZE_VERSION/dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz \
+    && tar -C /usr/local/bin -xzvf dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz \
+    && rm dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz
+
+ENV NODE_ENV=production
+ENV PORT=3000
+
+EXPOSE 3000
+
+ENTRYPOINT dockerize -wait tcp://${DB_HOST}:3306 \
+  && npx sequelize db:migrate \
+  && node dist/server.js