adjust dockerfile again

src/aka.terribledev.io/Dockerfile

@@ -1,16 +1,16 @@
-FROM microsoft/dotnet:2.1.400-sdk-alpine3.7
-
-COPY . /app
-
+FROM microsoft/dotnet:2.1-sdk AS build
 WORKDIR /app
 
-RUN ["dotnet", "restore"]
+# copy csproj and restore as distinct layers
+COPY aka.terribledev.io.csproj .
+RUN dotnet restore
 
-RUN ["dotnet", "build", "--configuration", "Release"]
+# copy everything else and build app
+COPY . .
+RUN dotnet publish -c Release -o out
 
-RUN 'ls'
-ENV ASPNETCORE_ENVIRONMENT Production
-ENV ASPNETCORE_URLS http://*:5000
-EXPOSE 5000/tcp
 
-CMD ["dotnet", "run", "--configuration", "Release"]
+FROM microsoft/dotnet:2.1-aspnetcore-runtime AS runtime
+WORKDIR /app
+COPY --from=build /app/out ./
+ENTRYPOINT ["dotnet", "aka.terribledev.io.dll"]