Build a Docker image using multi-stage builds

Author: foriequal0

.dockerignore

@@ -1,4 +1,6 @@
 /.git/
+/.idea/
 /target/
 /keys/
 /db/
+/docker/

docker/ubuntu/Dockerfile

@@ -1,4 +1,4 @@
-FROM ubuntu:14.04
+FROM ubuntu:14.04 as builder
 WORKDIR /build
 
 # install tools and dependencies
@@ -38,8 +38,14 @@ RUN cd codechain && \
 
 RUN file /build/codechain/target/release/codechain
 
-WORKDIR /build/codechain
 
-EXPOSE 3485 8080
-ENTRYPOINT ["target/release/codechain"]
+FROM ubuntu:14.04
+WORKDIR /app/codechain
+COPY --from=builder /build/codechain/target/release/codechain ./target/release/codechain
+COPY --from=builder /build/codechain/codechain/config/presets/ ./codechain/config/presets
 
+# show backtraces
+ENV RUST_BACKTRACE 1
+
+EXPOSE 3485 8080
+ENTRYPOINT ["target/release/codechain"]