moby: Windows docker doesn't honor --dns-search option

PS C:\go\src\github.com> git clone https://github.com/moby/moby.git docker/docker
Cloning into 'docker/docker'...
remote: Counting objects: 242109, done.
remote: Compressing objects: 100% (20/20), done.
remote: Total 242109 (delta 4), reused 4 (delta 3), pack-reused 242086
Receiving objects: 100% (242109/242109), 134.51 MiB | 1.06 MiB/s, done.
Resolving deltas: 100% (161471/161471), done.
PS C:\go\src\github.com> cd C:\go\src\github.com\docker\docker
PS C:\go\src\github.com\docker\docker> docker build -t nativebuildimage -f Dockerfile.windows .
Sending build context to Docker daemon  38.83MB
Step 1/7 : FROM microsoft/windowsservercore
 ---> 1fbef5019583
Step 2/7 : SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
 ---> Using cache
 ---> 5ba4a5492a58
Step 3/7 : ENV GO_VERSION=1.9.2     GIT_VERSION=2.11.1     GOPATH=C:\go     FROM_DOCKERFILE=1
 ---> Using cache
 ---> fe9eb6d7bede
Step 4/7 : RUN   Function Test-Nano() {     $EditionId = (Get-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion' -Name 'EditionID').EditionId;     return (($EditionId -eq 'ServerStandardNano') -or ($EditionId -eq 'ServerDataCenterNano') -or ($EditionId -eq 'NanoServer'));   }    Function Download-File([string] $source, [string] $target) {     if (Test-Nano) {       $handler = New-Object System.Net.Http.HttpClientHandler;       $client = New-Object System.Net.Http.HttpClient($handler);       $client.Timeout = New-Object System.TimeSpan(0, 30, 0);       $cancelTokenSource = [System.Threading.CancellationTokenSource]::new();       $responseMsg = $client.GetAsync([System.Uri]::new($source), $cancelTokenSource.Token);       $responseMsg.Wait();       if (!$responseMsg.IsCanceled) {         $response = $responseMsg.Result;         if ($response.IsSuccessStatusCode) {           $downloadedFileStream = [System.IO.FileStream]::new($target, [System.IO.FileMode]::Create, [System.IO.FileAccess]::Write);           $copyStreamOp = $response.Content.CopyToAsync($downloadedFileStream);           $copyStreamOp.Wait();           $downloadedFileStream.Close();           if ($copyStreamOp.Exception -ne $null) { throw $copyStreamOp.Exception }         }       } else {       Throw ("Failed to download " + $source)       }    } else {       $webClient = New-Object System.Net.WebClient;       $webClient.DownloadFile($source, $target);     }   }     setx /M PATH $('C:\git\cmd;C:\git\usr\bin;'+$Env:PATH+';C:\gcc\bin;C:\go\bin');     Write-Host INFO: Downloading git...;   $location='https://www.nuget.org/api/v2/package/GitForWindows/'+$Env:GIT_VERSION;   Download-File $location C:\gitsetup.zip;     Write-Host INFO: Downloading go...;   Download-File $('https://golang.org/dl/go'+$Env:GO_VERSION+'.windows-amd64.zip') C:\go.zip;     Write-Host INFO: Downloading compiler 1 of 3...;   Download-File https://raw.githubusercontent.com/jhowardmsft/docker-tdmgcc/master/gcc.zip C:\gcc.zip;     Write-Host INFO: Downloading compiler 2 of 3...;   Download-File https://raw.githubusercontent.com/jhowardmsft/docker-tdmgcc/master/runtime.zip C:\runtime.zip;     Write-Host INFO: Downloading compiler 3 of 3...;   Download-File https://raw.githubusercontent.com/jhowardmsft/docker-tdmgcc/master/binutils.zip C:\binutils.zip;     Write-Host INFO: Extracting git...;   Expand-Archive C:\gitsetup.zip C:\git-tmp;   New-Item -Type Directory C:\git | Out-Null;   Move-Item C:\git-tmp\tools\* C:\git\.;   Remove-Item -Recurse -Force C:\git-tmp;     Write-Host INFO: Expanding go...;   Expand-Archive C:\go.zip -DestinationPath C:\;     Write-Host INFO: Expanding compiler 1 of 3...;   Expand-Archive C:\gcc.zip -DestinationPath C:\gcc -Force;   Write-Host INFO: Expanding compiler 2 of 3...;   Expand-Archive C:\runtime.zip -DestinationPath C:\gcc -Force;   Write-Host INFO: Expanding compiler 3 of 3...;   Expand-Archive C:\binutils.zip -DestinationPath C:\gcc -Force;     Write-Host INFO: Removing downloaded files...;   Remove-Item C:\gcc.zip;   Remove-Item C:\runtime.zip;   Remove-Item C:\binutils.zip;   Remove-Item C:\gitsetup.zip;     Write-Host INFO: Creating source directory...;   New-Item -ItemType Directory -Path C:\go\src\github.com\docker\docker | Out-Null;     Write-Host INFO: Configuring git core.autocrlf...;   C:\git\cmd\git config --global core.autocrlf true;     Write-Host INFO: Completed
 ---> Using cache
 ---> f7e069c80bd7
Step 5/7 : ENTRYPOINT ["powershell.exe"]
 ---> Using cache
 ---> 4c0bcd896163
Step 6/7 : WORKDIR C:\go\src\github.com\docker\docker
 ---> Using cache
 ---> 6b897bdb859a
Step 7/7 : COPY . .
 ---> e88b696baa98
Successfully built e88b696baa98
Successfully tagged nativebuildimage:latest
PS C:\go\src\github.com\docker\docker> $DOCKER_GITCOMMIT=(git rev-parse --short HEAD)
PS C:\go\src\github.com\docker\docker> docker run --name binaries -e DOCKER_GITCOMMIT=$DOCKER_GITCOMMIT nativebuildimage hack\make.ps1 -Binary
INFO: make.ps1 starting at 12/07/2017 16:53:41
INFO: Git commit (8fe0a759f) assumed from DOCKER_GITCOMMIT environment variable
INFO: Invoking autogen...
INFO: Building daemon...
INFO: Downloading docker/cli version 17.06.0-ce from edge...

 ________   ____  __.
 \_____  \ |    |/ _|
 /   |   \|      <
 /    |    \    |  \
 \_______  /____|__ \
         \/        \/

INFO: make.ps1 ended at 12/07/2017 16:55:10
PS C:\go\src\github.com\docker\docker> docker cp binaries:C:\go\src\github.com\docker\docker\bundles\docker.exe C:\docker.exe
PS C:\go\src\github.com\docker\docker> docker cp binaries:C:\go\src\github.com\docker\docker\bundles\dockerd.exe C:\dockerd.exe
PS C:\go\src\github.com\docker\docker> Stop-Service Docker
PS C:\go\src\github.com\docker\docker> cp 'C:\Program Files\Docker\docker.exe' C:\docker_old.exe
PS C:\go\src\github.com\docker\docker> cp 'C:\Program Files\Docker\dockerd.exe' C:\dockerd_old.exe
PS C:\go\src\github.com\docker\docker> cp C:\docker.exe 'C:\Program Files\Docker\docker.exe'
PS C:\go\src\github.com\docker\docker> cp C:\dockerd.exe 'C:\Program Files\Docker\dockerd.exe'
PS C:\go\src\github.com\docker\docker> Start-Service Docker
PS C:\go\src\github.com\docker\docker> cd \
PS C:\> docker info
Containers: 17
 Running: 0
 Paused: 0
 Stopped: 17
Images: 3
Server Version: 0.0.0-dev
Storage Driver: windowsfilter
 Windows:
Logging Driver: json-file
Plugins:
 Volume: local
 Network: ics l2bridge l2tunnel nat null overlay transparent
 Log: awslogs etwlogs fluentd gelf json-file logentries splunk syslog
Swarm: inactive
Default Isolation: process
Kernel Version: 10.0 16299 (16299.15.amd64fre.rs3_release.170928-1534)
Operating System: Windows Server Standard
OSType: windows
Architecture: x86_64
CPUs: 4
Total Memory: 7.906GiB
Name: WIN-4S3SHUKUPQF
ID: DKLN:VWWU:YASC:WMTU:2ZEE:WWJL:EI5I:BHDP:PY25:Y26K:H3EH:2IGZ
Docker Root Dir: C:\ProgramData\docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Labels:
Experimental: false
Insecure Registries:
 127.0.0.0/8
Live Restore Enabled: false

PS C:\> docker network create -d nat --gateway 172.2.127.1 --subnet 172.2.127.0/24 -o com.docker.network.windowsshim.dnsservers=4.4.4.4,8.8.8.8 bla
a3cab95d91fb13b735961347db5bdf05f1e148cfb63d64bca6a657ab83b9f2b4
PS C:\> docker network ls
NETWORK ID          NAME                                                               DRIVER              SCOPE
a3cab95d91fb        bla                                                                nat                 local
73bb88756a8c        none                                                               null                local