significantly reduce build time of Dockerfile

Dockerfile

@@ -8,25 +8,19 @@ EXPOSE 46656
 EXPOSE 46657
 
 #-----------------------------------------------------------------------------
-# install eris-db
+# install eris-db's dependencies
 
 # set the source code path and copy the repository in
 ENV ERIS_DB_SRC_PATH $GOPATH/src/github.com/eris-ltd/eris-db
-COPY . $ERIS_DB_SRC_PATH
+ADD glide.yaml $ERIS_DB_SRC_PATH/
+ADD glide.lock $ERIS_DB_SRC_PATH/
+# [csk] if we vendor the dependencies we should import them b4 the glide install, no?
 
-# fetch and install eris-db and its dependencies
-	# install glide for dependency management
+# install glide for dependency management
 RUN go get github.com/Masterminds/glide \
 	# install dependencies for eris-db with glide
 	&& cd $ERIS_DB_SRC_PATH \
-	&& glide install \
-	# build the main eris-db target
-	&& cd $ERIS_DB_SRC_PATH/cmd/eris-db \
-	&& go build \
-	&& cp eris-db $INSTALL_BASE/eris-db \
-	# copy the start script for eris-db \
-	&& cp $ERIS_DB_SRC_PATH/bin/start_eris_db $INSTALL_BASE/erisdb-wrapper \
-	&& chmod 755 $INSTALL_BASE/erisdb-wrapper
+	&& glide install
 
 #-----------------------------------------------------------------------------
 # install mint-client [to be deprecated]
@@ -48,6 +42,21 @@ RUN git clone --quiet https://$ERIS_DB_MINT_REPO . \
 	# && go build -o $INSTALL_BASE/mintgen ./mintgen \
 	# && go build -o $INSTALL_BASE/mintsync ./mintsync
 
+#-----------------------------------------------------------------------------
+# install eris-db
+
+# copy in the entire repo now (after dependencies installed)
+COPY . $ERIS_DB_SRC_PATH
+
+# build the main eris-db target
+RUN cd $ERIS_DB_SRC_PATH/cmd/eris-db \
+	# statically link Alpine's c library to provide X-Linux buildability
+	# [csk] see -> https://github.com/eris-ltd/eris-pm/commit/e24c49c7ba1e62509377adacf8da650b51e84e6a
+	&& go build --ldflags '-extldflags "-static"' -o $INSTALL_BASE/eris-db \
+	# copy the start script for eris-db \
+	&& cp $ERIS_DB_SRC_PATH/bin/start_eris_db $INSTALL_BASE/erisdb-wrapper \
+	&& chmod 755 $INSTALL_BASE/erisdb-wrapper
+
 #-----------------------------------------------------------------------------
 # clean up [build container needs to be separated from shipped container]