Re: [PATCH] tests/functional/qemu_test/asset.py: Don't use setxattr when it doesn't exist

["Alex Bennée" <alex.bennee@linaro.org>]

Peter Maydell <peter.maydell@linaro.org> writes:

> The Python os.setxattr() API is Linux-specific, so trying to use
> it on other OSes triggers a failure:
>
>   File "/Users/pm215/src/qemu/tests/functional/qemu_test/asset.py",
> line 227, in fetch
>     os.setxattr(str(tmp_cache_file), "user.qemu-asset-url",
>     ^^^^^^^^^^^
> AttributeError: module 'os' has no attribute 'setxattr'
>
> Since we only set the attributes here for informational
> purposes, skip them when os.setxattr() isn't available.
>
> Cc: qemu-stable@nongnu.org
> Fixes: 9903217a4ed013 ("tests/functional: add a module for handling asset download & caching")
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  tests/functional/qemu_test/asset.py | 13 ++++++++-----
>  1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/tests/functional/qemu_test/asset.py b/tests/functional/qemu_test/asset.py
> index 51a434b2b7..0abd89e0a3 100644
> --- a/tests/functional/qemu_test/asset.py
> +++ b/tests/functional/qemu_test/asset.py
> @@ -223,11 +223,14 @@ def fetch(self):
>              raise AssetError(self, "Download retries exceeded", transient=True)
>  
>          try:
> -            # Set these just for informational purposes
> -            os.setxattr(str(tmp_cache_file), "user.qemu-asset-url",
> -                        self.url.encode('utf8'))
> -            os.setxattr(str(tmp_cache_file), "user.qemu-asset-hash",
> -                        self.hash.encode('utf8'))
> +            # Set these just for informational purposes. Note that
> +            # setxattr is Linux-only; as this is only informational
> +            # we can simply skip it on other platforms.
> +            if hasattr(os, "setxattr"):
> +                os.setxattr(str(tmp_cache_file), "user.qemu-asset-url",
> +                            self.url.encode('utf8'))
> +                os.setxattr(str(tmp_cache_file), "user.qemu-asset-hash",
> +                            self.hash.encode('utf8'))

Well TIL:

  attr -g qemu-asset-url /home/alex/.cache/qemu/download/ff9d7dd7c6bdba325bd85ee85c02db61ff653e129558aeffe6aff55bffb6763a
  Attribute "qemu-asset-url" had a 73 byte value for /home/alex/.cache/qemu/download/ff9d7dd7c6bdba325bd85ee85c02db61ff653e129558aeffe6aff55bffb6763a:
  https://qemu-advcal.gitlab.io/qac-best-of-multiarch/download/day20.tar.xz

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

>          except OSError as e:
>              self.log.debug("Unable to set xattr on %s: %s", tmp_cache_file, e)

-- 
Alex Bennée
Virtualisation Tech Lead @ Linaro