USER instruction appears to be ignored for LCOW

[solvingj]

Dockerfile

FROM ubuntu:trusty

RUN useradd -ms /bin/bash testuser \
    && printf "testuser:testuser" | chpasswd \
    && adduser testuser sudo \
    && printf "testuser ALL= NOPASSWD: ALL\\n" >> /etc/sudoers

USER testuser
RUN whoami
CMD whoami

Build Log

c:\Users\me\Desktop>docker build . --platform=linux -t dockeruserfail
Sending build context to Docker daemon  103.4kB
Step 1/5 : FROM ubuntu:trusty
 ---> 3b853789146f
Step 2/5 : RUN useradd -ms /bin/bash testuser     && printf "testuser:testuser" | chpasswd     && adduser testuser sudo     && printf "testuser ALL= NOPASSWD: ALL\\n" >> /etc/sudoers
 ---> Using cache
 ---> b86bffa2a6bf
Step 3/5 : USER testuser
 ---> Using cache
 ---> 94849a0d376c
Step 4/5 : RUN whoami
 ---> Using cache
 ---> d63f59ce1c1e
Step 5/5 : CMD whoami
 ---> Using cache
 ---> e35c44ded873
Successfully built e35c44ded873
Successfully tagged dockeruserfail:latest

c:\Users\me\Desktop>docker run dockeruserfail
root

Environment

Version 18.04.0-ce-win62 (17151)
Channel: edge
e0a85f6
Windows 10 Pro for Workstations Insider Preview
1803
17639.1000

[solvingj]

Additionally, adding a RUN or CMD instruction at the end to su testuser has no effect. You also cannot pass su testuser in the command as in docker run ... /bin/sh -c 'su testuser && whoami'

[spgennard]

I hit the same problem too.