Merge pull request #4554 from smazmi/fix-buildkit-cni-symlink-docs

fix: filter non-executable files when symlinking buildkit-cni plugins (#4553)

Author: AkihiroSuda

Dockerfile

@@ -167,7 +167,7 @@ RUN BUILDKIT_VERSION=${BUILDKIT_VERSION%%@*}; \
   grep "${fname}" "/SHA256SUMS.d/buildkit-${BUILDKIT_VERSION}" | sha256sum -c && \
   tar xzf "${fname}" -C /out && \
   rm -f "${fname}" /out/bin/buildkit-qemu-* /out/bin/buildkit-cni-* /out/bin/buildkit-runc && \
-  for f in /out/libexec/cni/*; do ln -s ../libexec/cni/$(basename $f) /out/bin/buildkit-cni-$(basename $f); done && \
+  for f in /out/libexec/cni/*; do [ -x "$f" ] && [ -f "$f" ] && ln -s ../libexec/cni/$(basename $f) /out/bin/buildkit-cni-$(basename $f); done && \
   echo "- BuildKit: ${BUILDKIT_VERSION}" >> /out/share/doc/nerdctl-full/README.md
 # NOTE: github.com/moby/buildkit/examples/systemd is not included in BuildKit v0.8.x, will be included in v0.9.x
 RUN cd /out/lib/systemd/system && \