currencyservice: Optimized Docker image with multi stage builds, and using alpine as a base image. (#70)

src/currencyservice/Dockerfile

@@ -1,10 +1,32 @@
-FROM node:8
+FROM node:8-alpine as base
+
+FROM base as builder
+
+# Some packages (e.g. @google-cloud/profiler) require additional
+# deps for post-install scripts
+RUN apk add --update --no-cache \
+    python \
+    make \
+    g++
+
+WORKDIR /usr/src/app
+
+COPY package*.json ./
+
+RUN npm install --only=production
+
+FROM base
+
 RUN GRPC_HEALTH_PROBE_VERSION=v0.1.0-alpha.1 && \
     wget -qO/bin/grpc_health_probe https://github.com/grpc-ecosystem/grpc-health-probe/releases/download/${GRPC_HEALTH_PROBE_VERSION}/grpc_health_probe-linux-amd64 && \
     chmod +x /bin/grpc_health_probe
+
 WORKDIR /usr/src/app
-COPY package*.json ./
-RUN npm install --only=production
+
+COPY --from=builder /usr/src/app/node_modules ./node_modules
+
 COPY . .
+
 EXPOSE 7000
-CMD [ "node", "server.js" ]
+
+ENTRYPOINT [ "node", "server.js" ]