As motivation for this; we have had two breakouts of dib in recent
memory. One was a failure to unmount through symlinks in the core
code (I335316019ef948758392b03e91f9869102a472b9) and the other was
removing host keys on the build-system
(Ib01d71ff9415a0ae04d963f6e380aab9ac2260ce).
For the most part, dib runs unprivileged. Bits of the core code are
hopefully well tested (modulo bugs like the first one!). We give free
reign inside the chroot (although there is still some potential there
for adverse external affects via bind mounts). Where we could be a
bit safer (and could have prevented at least the second of these
breakouts) is with some better checking that the "sudo" calls
*outside* the chroot at least looked sane.
This adds a basic check that we're using chroot or image paths when
calling sudo in those parts of elements that run *outside* the chroot.
Various files are updated to accomodate this check; mostly by just
ignoring it for existing code (I have not audited these calls).
Nobody is pretending this type of checking makes dib magically safe,
or removes the issues with it needing to do things as root during the
build. But this can help find egregious errors like the key removal.
Change-Id: I161a5aea1d29dcdc7236f70d372c53246ec73749
The loopback handling in the Linux kernel limits the filenames of
files associated to loopback devices, see also linux/loop.h.
This is reflected also on userspace, as kpartx will silently do nothing
(exiting with 0) when requesting to remove a filename longer than 64
characters, as that name will obviously not match the truncated
filename. The result of this is that, when extracting qcow2 images for
the first time, if the qcow2 filename is long enough then the loopback
device will not be removed, remaining as stale in the host.
As a workaround, use a temporary file name when convering a qcow2 image
to raw, instead of using the base name of the qcow2 file.
While this still will not fix the issue when manually using a long
temporary directory (e.g. TMP_DIR=/very/long/etc...), at least should
avoid it in other cases.
Change-Id: Ibf46cd313a9d89412c0e1068fa0993be6c5a29db
There is a wide variety of tracing options through the various shell
scripts. Some use "set -eux", others explicity set xtrace and others
do nothing. There is a "-x" option to bin/disk-image-create but it
doesn't flow down to the many scripts it calls.
This adds a global integer variable set by disk-image-create
DIB_DEBUG_TRACE. All scripts have a stanza added to detect this and
turn on tracing. Any other tracing methods are rolled into this. So
the standard header is
---
if [ "${DIB_DEBUG_TRACE:-0}" -gt 0 ]; then
set -x
fi
set -eu
set -o pipefail
---
Multiple -x options can be specified to dib-create-image, which
increases the value of DIB_DEBUG_TRACE. If script authors feel their
script should only trace at higher levels, they should modify the
"-gt" value. If they feel it should trace by default, they can modify
the default value also.
Changes to pachset 16 : scripts which currently trace themselves by
default have retained this behaviour with DIB_DEBUG_TRACE defaulting
to "1". This was done by running [1] on patch set 15. See the thread
beginning at [2]
dib-lint is also updated to look for the variable being matched.
[1] https://gist.github.com/ianw/71bbda9e6acc74ccd0fd
[2] http://lists.openstack.org/pipermail/openstack-dev/2014-November/051575.html
Change-Id: I6c5a962260741dcf6f89da9a33b96372a719b7b0
Ubuntu has recently release their "Snappy Ubuntu Core" which is a
minimal base-layer for running docker applications. Seems like the sort
of thing someone might want to use for tasks.
Change-Id: I6cb724451d1862121dee4ccf1f599ab8938f0b7f
