Update Dockerfile

Dockerfile

-FROM node:latest as build
-RUN apt-get update && apt-get install -y --no-install-recommends git && mkdir -p /usr/src/app/ && rm -rf /var/lib/apt/lists/*
-RUN npm install -g @angular/cli
-RUN npm install -g npm@latest
-ENV NODE_PATH=/usr/local/lib/node_modules/:/usr/local/lib  NODE_ENV=production
-WORKDIR /usr/src/app
-COPY package.json  /usr/src/app/
-RUN npm install
-RUN npm install node-sass@latest
-COPY . /usr/src/app/
-RUN ng build --sourcemap=false
-FROM nginx:latest
+### STAGE 1: Build ###
+
+# We label our stage as 'builder'
+FROM node:9-alpine as builder
+
+COPY package.json package-lock.json ./
+
+RUN npm set progress=false && npm config set depth 0 && npm cache clean --force
+
+## Storing node modules on a separate layer will prevent unnecessary npm installs at each build
+RUN npm i && mkdir /ng-app && cp -R ./node_modules ./ng-app
+
+WORKDIR /ng-app
+
+COPY . .
+
+## Build the angular app in production mode and store the artifacts in dist folder
+RUN $(npm bin)/ng build --prod
+
+
+### STAGE 2: Setup ###
+
+FROM nginx:1.13.3-alpine
+
+## Copy our default nginx config
 COPY nginx/default.conf /etc/nginx/conf.d/
+
+## Remove default nginx website
 RUN rm -rf /usr/share/nginx/html/*
-COPY --from=build /usr/src/app/dist /usr/share/nginx/html
-CMD ["nginx", "-g", "daemon off;"]
\ No newline at end of file
+
+## From 'builder' stage copy over the artifacts in dist folder to default nginx public folder
+COPY --from=builder /ng-app/dist /usr/share/nginx/html
+
+CMD ["nginx", "-g", "daemon off;"]