cartservice: dockerfile optimizations

Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>

src/cartservice/Dockerfile

@@ -1,9 +1,9 @@
 FROM gcr.io/google-appengine/aspnetcore:2.1.0
-COPY . /app
-WORKDIR /app
-RUN dotnet restore
-RUN dotnet build
-RUN dotnet publish
-WORKDIR /app/bin/Debug/netcoreapp2.0
 RUN apt update && apt install net-tools telnet
+WORKDIR /app
+COPY . .
+RUN dotnet restore && \
+    dotnet build \
+    dotnet publish
+WORKDIR /app/bin/Debug/netcoreapp2.0
 ENTRYPOINT ["dotnet", "cartservice.dll", "start"]

src/frontend/Dockerfile

@@ -5,6 +5,7 @@ WORKDIR /go/src/frontend
 # fetch known dependencies for caching
 RUN go get -d github.com/google/uuid \
     github.com/gorilla/mux \
+    github.com/pkg/errors \
     google.golang.org/grpc \
     google.golang.org/grpc/codes \
     google.golang.org/grpc/status