docker - 将文件复制到root时构建失败

Question

I'm getting a docker build error when I try to add a shell script to the root directory (/entrypoint.sh)

Dockerfile:

FROM ubuntu:trusty
COPY ./entrypoint.sh /
ENTRYPOINT ["/entrypoint.sh"]

Output:

Sending build context to Docker daemon 3.072 kB
Step 1 : FROM ubuntu:trusty
 ---> 1e0c3dd64ccd
Step 2 : COPY ./entrypoint.sh /
stat /var/lib/docker/aufs/mnt/5570570a77deddea426b95bd0f706beff4b5195a2fba4a8f70dcac4671bca225/entrypoint.sh: no such file or directory

The file is present at the root of the build context, and when I change / to a subdirectory such as /opt/, it works. Any idea what could be going wrong?

Answer 1

It turns out restarting the daemon solves the issue. See https://github.com/docker/docker/issues/25925 .