Ubuntu
lsb-release-minimal package

alternative-bin-sh autopkgtest redirect tar to busybox

Bug #2004500 reported by Paride Legovini
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
lsb-release-minimal (Ubuntu)
Fix Released
High
Brian Murray

Bug Description

The alternative-bin-sh autopkgtest is meant to run a set of tests using busybox as /bin/sh, however this somehow happens to also redirect /bin/tar. This causes autopkgtest failures. To reproduce locally fetch the lsb-release-minimal (12.0-1) source tree and run:

autopkgtest --test-name=alternative-bin-sh -s -U --no-built-binaries ./lsb-release-minimal-12.0/ --apt-pocket=proposed=lsb-release-minimal -- lxd ubuntu-daily:lunar

Sample error:

autopkgtest [19:09:08]: test alternative-bin-sh: - - - - - - - - - - results - - - - - - - - - -
alternative-bin-sh PASS
tar: unrecognized option '--warning=none'
BusyBox v1.35.0 (Ubuntu 1:1.35.0-4ubuntu1) multi-call binary.

Usage: tar c|x|t [-ZzJjahmvokO] [-f TARFILE] [-C DIR] [FILE]...

Create, extract, or list files from a tar file

 c Create
 x Extract
 t List
 -f FILE Name of TARFILE ('-' for stdin/out)
 -C DIR Change to DIR before operation
 -v Verbose
 -O Extract to stdout
 -m Don't restore mtime
 -o Don't restore user:group
 -k Don't replace existing files
 -Z (De)compress using compress
 -z (De)compress using gzip
 -J (De)compress using xz
 -j (De)compress using bzip2
 --lzma (De)compress using lzma
 -a (De)compress based on extension
 -h Follow symlinks
 --overwrite Replace existing files
 --strip-components NUM NUM of leading components to strip
 --no-recursion Don't descend in directories
 --numeric-owner Use numeric user:group
 --no-same-permissions Don't restore access permissions
 --to-command COMMAND Pipe files to COMMAND
tar: This does not look like a tar archive
tar: Exiting with failure status due to previous errors
autopkgtest-virt-lxd [19:09:08]: copyup destination failed, status 2

Revision history for this message
Paride Legovini (paride) wrote :

With debugging enabled (autopkgtest --debug):

alternative-bin-sh PASS
autopkgtest: DBG: sending command to testbed: copyup /tmp/autopkgtest.xGweVn/alternative-bin-sh-artifacts/ /tmp/autopkgtest.output.4y26hx9u/artifacts/
tar: unrecognized option '--warning=none'

tags: added: update-excuse
Revision history for this message
Paride Legovini (paride) wrote :

It reasonable to decide that an Ubuntu system with busybox as its /bin/sh is broken, so we don't have a "good" autopkgtest here. Making the autopkgtest undo the /bin/sh redirect should make it pass, but it's still kind of weak test as should a failure happen before the "undo redirect" code we'd and up with a "testbed failure" again.

Do we care about testing with busybox as /bin/sh in Ubuntu?

Revision history for this message
Gioele Barabucci (gioele) wrote :

Thanks Paride for the report and the analysis.

To me this looks like a bug in autopkgtest-virt-lxd: why is the runner executing any command inside an environment that has been modified (and possibly broken) by a test with `Restrictions: breaks-testbed`?

Revision history for this message
Brian Murray (brian-murray) wrote (last edit ):

Reordering the tests so that /bin/bash or /bin/dash are the final symlink for /bin/sh allows tar to proceed. I'll upload something shortly because our workers are currently stuck trying to run this package's tests. We should investigate further the comment regarding running tar in a "broken testbed".

Brian Murray (brian-murray)
Changed in lsb-release-minimal (Ubuntu):
status: New → In Progress
assignee: nobody → Brian Murray (brian-murray)
importance: Undecided → High
Revision history for this message
Gioele Barabucci (gioele) wrote :

Instead of reordering the tests, I'd just add

    trap 'ln -s /bin/dash /bin/sh' EXIT

at the end of the test script. That will fix the testbed regardless of any possible test failure.

Revision history for this message
Paride Legovini (paride) wrote (last edit ):

Hi Gioele,

AIUI from [1] the breaks-testbed restriction does not ensure that no further command gets executed on the testbed system.

The alternative-bin-sh autopkgtest works in Debian because autopkgtest-virt-lxc (like many other virt servers) has the downtmp-host capability, which allows autopkgtest to retrieve artifacts using a directory which is shared with the host system. The lxd and qemu virt servers do not have this capability, so artifacts are retrieved by building a tarball on the testbed system (executing commands there) and then retrieving it (I didn't check exactly how). I don't think we have a bug in autopkgtest(-virt-lxd) here.

I think the trap you suggested should be added to alternative-bin-sh in Debian.

For downtmp-host see [2]. Thanks for chiming in!

[1] https://salsa.debian.org/ci-team/autopkgtest/-/blob/master/doc/README.package-tests.rst
[2] https://salsa.debian.org/ci-team/autopkgtest/-/blob/master/doc/README.virtualisation-server.rst

Revision history for this message
Steve Langasek (vorlon) wrote :

bug was only present in -proposed and is now fixed in -proposed; closing.

Changed in lsb-release-minimal (Ubuntu):
status: In Progress → Fix Released
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