example: use multistage builds to better demostrate use of dev and prod images

bitnami/node/example/Dockerfile

@@ -1,4 +1,4 @@
-FROM bitnami/node:6-prod
+FROM bitnami/node:6 as builder
 
 ENV NODE_ENV="production"
 
@@ -8,4 +8,14 @@ WORKDIR /app
 
 RUN npm install
 
+FROM bitnami/node:6-prod
+
+ENV NODE_ENV="production"
+
+COPY --from=builder /app /app
+
+WORKDIR /app
+
+EXPOSE 3000
+
 CMD ["npm", "start"]