Class confinement for Python snaps
didier.roche at canonical.com
Fri Mar 10 15:52:08 UTC 2017
Le 10/03/2017 à 16:14, Barry Warsaw a écrit :
> I'm converting ubuntu-image from a devmode snap to a classic snap, but I'm
> running into some problems. ubuntu-image is a Python 3 application, and I'm
> using snapcraft 2.27.1+17.4 on Zesty.
> The first problem I'm having is I think directly related to LP: #1670749.
Note as well that I opened
https://bugs.launchpad.net/snapcraft/+bug/1670388 against the snapcraft
project a couple of days ago.
I think snapcraft should at least fail the build to warn you about this.
> ended up reopening this because while Corey found that he ultimately only
> needed to set the $PATH environment variable, I still also had to $PYTHONPATH
> and I had to make sure the snap versions come before the system versions:
> PATH: $SNAP/bin/:$PATH
> PYTHONPATH: $SNAP/lib/python3.5/site-packages:$PYTHONPATH
> This gets me pretty close, but then I run into my second problem which is that
> we depend on pyparted, in Ubuntu as python3-pyparted. This package contains
> both Python source and an extension module and to further complicate things,
> its tarball is only released on GitHub, not on PyPI, so adding it to
> python-packages in the ubuntu-image part doesn't work. Further, it doesn't
> help to add python3-parted to stage-packages because it appears that with
> classic confinement, none of those Python packages end up in the snap.
> I tried to add a scriptlet to copy things over, but that also fails. E.g.:
> plugin: python
> source: https://github.com/CanonicalLtd/ubuntu-image.git
> source-type: git
> - PyYAML
> - attrs
> - voluptuous
> - bin/ubuntu-image
> - usr
> - lib
> - sbin
> - e2fsprogs
> - mtools
> - python3-debian
> - python3-parted
> - util-linux
> install: |
> cp -a ../install/usr/lib/python3/dist-packages/parted ../stage/lib/python3.5/site-packages
> cp -a ../install/usr/lib/python3/dist-packages/pyparted-*.egg-info ../stage/lib/python3.5/site-packages
> $ snapcraft
> cp: cannot create directory '../stage/lib/python3.5/site-packages': No such file or directory
> cp: cannot create regular file '../stage/lib/python3.5/site-packages': No such file or directory
> Command '['/bin/sh', '/tmp/tmpfeczxcco', '/tmp/tmp2__1bdau']' returned non-zero exit status 1
> This happens because ./stage/ is empty at the point that the install scriptlet
> is run.
> I can think of a couple of approaches that might be useful.
> * Allow python-packages specifications to pip install from repositories other
> than PyPI.
> * Allow python-packages to come from git and/or https URLs (I tried this and
> it didn't work).
> * Integrate dirtbike and wheels into the Python parts building phases.
> (dirtbike is a tool that Debian/Ubuntu uses in very limited cases to turn
> installed distro packages into .whl files.)
> * Provide a scriptlet hook that runs after the normal part installation step.
> My current WIP snapcraft.yaml file is here:
> I'm going to keep trying a few things, but any suggestions are welcome. I'm
> happy to file bugs as needed.
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