add duplicate namespace detection

[sky-big]

oci add duplicate namespace detection。

original pr: #1564

[sky-big]

@giuseppe please help reveiew。

[giuseppe]

please use a real name for your Signed-off-by line, run make clang-format and amend the changes.

[sky-big]

please use a real name for your Signed-off-by line, run make clang-format and amend the changes.

done

[giuseppe]

thanks, the DCO test is still failing. I think you need to change the author field in the commit as well. You can use git commit --amend --author="Xingwen Xu <sky_big@yeah.net>"

[sky-big]

thanks, the DCO test is still failing. I think you need to change the author field in the commit as well. You can use git commit --amend --author="Xingwen Xu <sky_big@yeah.net>"

ok, done

[giuseppe]

LGTM