Support remote Docker hosts (was: how add -H in docker build in vs)

[gitlsl]

default build will get error in vs2017
docker build -f "E:\vsproject\TestDemo\WebApplication1\Dockerfile" -t webapplication1:dev --target base "E:\vsproject\TestDemo"

next is I need
docker -H tcp://192.168.34.211:2375 build -f "E:\vsproject\TestDemo\WebApplication1\Dockerfile" -t webapplication1:dev --target base "E:\vsproject\TestDemo"

but how can I add this?
thanks a lot

[gitlsl]

DOCKER_HOST add this to PATH is ok
1>docker run -dt -v "C:\Users\Administrator\vsdbg\vs2017u5:/remote_debugger:rw" -v "E:\vsproject\TestDemo\WebApplication1:/app" -v "C:\Users\Administrator\.nuget\packages\:/root/.nuget/fallbackpackages2" -v "C:\Program Files\dotnet\sdk\NuGetFallbackFolder:/root/.nuget/fallbackpackages" -e "DOTNET_USE_POLLING_FILE_WATCHER=1" -e "ASPNETCORE_ENVIRONMENT=Development" -e "NUGET_PACKAGES=/root/.nuget/fallbackpackages2" -e "NUGET_FALLBACK_PACKAGES=/root/.nuget/fallbackpackages;/root/.nuget/fallbackpackages2" -P --entrypoint tail webapplication1:dev -f /dev/null
1>docker: Error response from daemon: Mount denied:

[bwateratmsft]

Hey @gitlsl ,

Using a remote machine as the docker host is not supported by default as volume mapping is much more complicated. Volume mapping is necessary to use Debug mode in all cases, and in Release mode as well if you're using ASP.NET Core 2.1 + HTTPS. There may be a way to enable volume mapping (perhaps using a network drive?) but we have not investigated or tested this.

[gitlsl]

@bwateratmsft OK , wish you can add this feature

[SpoonsJTD]

I have worked around this by removing the Docker for Windows install dir from the env path, and adding a docker.bat into the env path that calls docker.exe directly using the -H option and passing all other options to the exe. As bwateratmsft explained, it does break debugging, but I switch the debugging over to use IIS Express for dev testing, then do full testing after deploying the image to a staging docker environment by 'Publish'ing it to a custom registry running on the staging environment.