Show `snap prepare-image` stdout for awsome download progress

[Michael Vogt]

Please just connect the stdout from snap prepare-image to the users stdout in ubuntu-image. This will give us nice progress display. Right now there is a long delay in u-i when the download happens without any output.

[Barry Warsaw (barry)]

On Sep 01, 2016, at 09:03 AM, Michael Vogt wrote:

>Please just connect the stdout from snap prepare-image to the users
>stdout in ubuntu-image. This will give us nice progress display. Right
>now there is a long delay in u-i when the download happens without any
>output.

There should be some controls to optionally suppress this. Whether that means
print-by-default with a --quiet option or a don't-print-by-default with a
--verbose option I'm not sure.

[Michael Vogt (mvo)]

https://github.com/CanonicalLtd/ubuntu-image/pull/46/commits/181e288390b225aef72a0cd3a35e9d492cc3b42c

[Michael Vogt (mvo)]

Fixed in latest master.

[Steve Langasek (vorlon)]

ubuntu-image (0.6ubuntu1) yakkety; urgency=medium

  * Add --extra-snaps option to support specifying extra snaps to include.
    LP: #1619219.
  * Show output of snap prep-image, so that the user gets download progress
    instead of long pauses with no activity. LP: #1619194.
  * Only set UBUNTU_IMAGE_SKIP_COPY_UNVERIFIED_MODEL in tests, now that
    model assertions are live. LP: #1619374.