nginx serving Angular 4 application built as Docker multi-stage image

Dockerfile

FROM node:8.1.2-onbuild as builder
ARG TARGET=production
RUN npm install @angular/cli
RUN node_modules/.bin/ng build -aot --target ${TARGET}

FROM nginx:1.13-alpine
COPY nginx.conf /etc/nginx/conf.d/
COPY --from=builder /usr/src/app/dist /usr/src/app

nginx.conf

server {
  listen 80;
  sendfile on;
  default_type application/octet-stream;

  gzip on;
  gzip_http_version 1.1;
  gzip_disable      "MSIE [1-6]\.";
  gzip_min_length   256;
  gzip_vary         on;
  gzip_proxied      expired no-cache no-store private auth;
  gzip_types        text/plain text/css application/json application/javascript application/x-javascript text/xml application/xml application/xml+rss text/javascript;
  gzip_comp_level   9;

  root /usr/src/app;

  location / {
    try_files $uri $uri/ /index.html =404;
  }
}