[elbe-devel] [PATCH 1/5] packers: add Packer class implementation

[John Ogness]

Hi Torben,

On 2019-01-28, Torben Hohn <torben.hohn at linutronix.de> wrote:
> using tar as a packer can not be modelled using the tuples
> approach.
>
> Implement a Baseclass and a dict mapping packernames to
> Packer objects. Also implement NoPacker class, which does nothing
> and returns the fname right away.
>
> Signed-off-by: Torben Hohn <torben.hohn at linutronix.de>
> ---
>  elbepack/packers.py | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 77 insertions(+)
>  create mode 100644 elbepack/packers.py
>
> diff --git a/elbepack/packers.py b/elbepack/packers.py
> new file mode 100644
> index 00000000..20680bc4
> --- /dev/null
> +++ b/elbepack/packers.py

[...]

> +class TarArchiver(Packer):
> +    # pylint: disable=too-few-public-methods
> +    def __init__(self, flag, suffix):
> +        self.flag = flag
> +        self.suffix = suffix
> +
> +    def pack_file(self, log, builddir, fname):
> +        try:
> +            fpath = os.path.join(builddir, fname)
> +            dirname = os.path.dirname(fpath)
> +            basename = os.path.basename(fpath)
> +            archname = fpath + self.suffix
> +            log.do('tar cv%sf "%s" --sparse -C "%s" "%s"' % (self.flag,
> +                                                             archname,
> +                                                             dirname,
> +                                                             basename))

Why not do:
               log.do('rm -f "%s"' % fpath)

Since the original file can't be used and it is really big, why waste
initvm space? I think it should be deleted.

> +        except CommandError:
> +            # in case of an error, we just return None
> +            # which means, that the orig file does not
> +            # exist anymore.
> +            #
> +            # Even if it actually exists, it might be
> +            # much to big to download it and remove
> +            # the sparsity.
> +            return None
> +
> +        return fname + self.suffix

John Ogness