1. Invalid references
2. Step 2/13 : WORKDIR C:\src
   the working directory 'C:src' is invalid, it needs to be an absolute path

As per Directions.md

1. Build the web app image
   docker image build -t nerd-dinner/web -f web\Dockerfile .

PS C:\docker\NerdDinner-master\NerdDinner-master> docker image build -t nerd-dinner/web -f web\Dockerfile .
Sending build context to Docker daemon 199.5 MB
Step 1/13 : FROM microsoft/dotnet-framework:4.7.2-sdk AS builder
Error parsing reference: "microsoft/dotnet-framework:4.7.2-sdk AS builder" is not a valid repository/tag: invalid reference format

Environment info using the latest AWS AMI for Windows Server 2016 with containers
(Maybe docker server version is too old and doesn't support format FROM [AS ] ??)

C:\Users\Administrator>docker info
Containers: 3
Running: 0
Paused: 0
Stopped: 3
Images: 24
Server Version: 1.12.2-cs2-ws-beta
Storage Driver: windowsfilter
Windows:
Logging Driver: json-file
Plugins:
Volume: local
Network: nat null overlay
Swarm: inactive
Default Isolation: process
Kernel Version: 10.0 14393 (14393.2430.amd64fre.rs1_release_inmarket_aim.180806-1810)
Operating System: Windows Server 2016 Datacenter
OSType: windows
Architecture: x86_64
CPUs: 4
Total Memory: 16 GiB
Name: EC2AMAZ-SOUFROL
ID: VZIV:QABT:63VB:KUOW:4FOR:BTTB:QULZ:U7KS:CIZK:QWTU:63SI:65EG
Docker Root Dir: C:\ProgramData\docker
Debug Mode (client): false
Debug Mode (server): false
Registry: https://index.docker.io/v1/
Insecure Registries:
127.0.0.0/8
Live Restore Enabled: false

Replacing all backslashes \ with forwardslashes /, and making the directory before setting workdir seems to make it work

escape=`

FROM microsoft/dotnet-framework:4.7.2-sdk

RUN mkdir C:/src
WORKDIR C:/src
COPY *.sln .
COPY NerdDinner/NerdDinner.csproj ./NerdDinner/
RUN nuget restore

COPY . C:/src
RUN msbuild NerdDinner/NerdDinner.csproj /p:OutputPath=c:/out /p:Configuration=Release

app image

FROM microsoft/aspnet:4.7.2-windowsservercore-ltsc2016
SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop';"]

ENV APP_ROOT=C:/web-app

WORKDIR ${APP_ROOT}
RUN Remove-Website -Name 'Default Web Site';New-Website -Name 'web-app' -Port 80 -PhysicalPath $env:APP_ROOT;
New-WebApplication -Name 'app' -Site 'web-app' -PhysicalPath $env:APP_ROOT

#COPY --from=microsoft/dotnet-framework:4.7.2-sdk C:/out/_PublishedWebsites/NerdDinner .