"Build from a remote build context, using a Dockerfile from stdin" example code fail

[durandg12]

File: develop/develop-images/dockerfile_best-practices.md

In the section Pipe Dockerfile through stdin, in the subsection named "Build from a remote build context, using a Dockerfile from stdin", the following piece of code fails:

docker build -t myimage:latest -f- https://github.com/docker-library/hello-world.git <<EOF
FROM busybox
COPY README.md .
EOF

Error message: COPY failed: stat /var/lib/docker/tmp/docker-builder857130722/README.md: no such file or directory.

After doing some research, I discovered the cause: .md files are listed in the .dockerignore file of the hello-world repo.

[docker-robott]

There hasn't been any activity on this issue for a long time.
If the problem is still relevant, mark the issue as fresh with a /remove-lifecycle stale comment.
If not, this issue will be closed in 14 days. This helps our maintainers focus on the active issues.

Prevent issues from auto-closing with a /lifecycle frozen comment.

/lifecycle stale

[durandg12]

/remove-lifecycle stale

[durandg12]

/lifecycle frozen

[durandg12]

I still see md files excluded from the dockerignore file

[dvdksn]

I can't reproduce this issue. I see that *.md is indeed included in the .dockerignore of the remote context, but the snippet builds just fine for me. @jedevc how does buildx/buildkit deal with .dockerignore in a remote context? Maybe this is a difference in the legacy builder vs buildkit.