Use intermediate build layers

frontend/Dockerfile

@@ -2,11 +2,17 @@
 
 FROM node:alpine AS build-image
 
+COPY package.json package-lock.json /app/
+
 WORKDIR /app
 
-COPY . .
+RUN npm ci
 
-RUN npm ci && npm run build
+COPY angular.json karma.conf.js protractor.conf.js README.md tsconfig.app.json tsconfig.json tslint.json /app/
+
+COPY src /app/src
+
+RUN npm run build
 
 # Stage 2