Daniel Hilst
7d52506a2d
The build lock is released in DESTROY, and perl does not run DESTROY when a signal
ends the process. A build stopped with SIGTERM or SIGINT therefore left its lock
directory behind, and the next build of that checkout died on
FATAL: another build of <path> already holds <dir> (held by [pid=NNNN])
naming a pid that had already exited. Nothing clears it but a person. One such
directory blocked an openSUSE target across three consecutive CI runs before anyone
looked at what the lock actually said.
buildrpms.pl has released its lock on cancellation for some time, through an END
block and an abort handler. This is the Debian builder catching up.
The order matters, and is the reason this is not simply an END block. The command in
flight is stopped BEFORE the lock is released: handing the checkout to a second build
while dpkg-buildpackage is still rewriting debian/changelog and debian/control in it
is worse than holding the lock a moment longer. The wait for that command is bounded,
so a subprocess that ignores the signal cannot hold the lock for ever either.
sh() now forks and execs rather than calling system(), because system() gives no pid
and a handler cannot stop what it cannot name. The child _exits rather than exits, so
it never runs the parent's END block and releases a lock the parent still holds.
The handler is installed by XCAT::BuildUtils::install_build_cancellation rather than
written inline in the builder, so a test can use the same wiring the builder uses. A
test that installs an equivalent handler of its own proves the helper works while
saying nothing about whether anything calls it -- the first version of this test did
exactly that, and passed with the wiring removed.
Release is idempotent: a signal handler and then DESTROY both reach it, and the
second must not remove a directory a LATER build has since taken.
builddebs_lock_cancellation.t terminates the holder, then takes the lock again, and
checks no build subprocess was orphaned. Verified by removing the wiring: assertions
9 through 12 fail, naming the leaked lock, the refused build and the stray process.
Signed-off-by: Daniel Hilst <392820+dhilst@users.noreply.github.com>
xCAT-test/unit
Unit tests. These run against the source tree only -- no xCAT installation, no running daemons, no management node.
They are executed on every pull request by the xcat_test GitHub Actions workflow,
which calls run_unit_tests() in github_action_xcat_test.pl:
prove -r xCAT-test/unit
You can run exactly the same thing from a clean checkout:
cd <xcat-core checkout>
prove -r xCAT-test/unit
What belongs here
A test belongs in unit/ when everything it needs is in the checkout: plugin and
library sources, kickstart/preseed/subiquity templates, postscripts, packaging
metadata. Such a test asserts on rendered output or module logic and reaches the
repository root through FindBin:
use FindBin;
use lib "$FindBin::Bin/../../perl-xCAT";
use lib "$FindBin::Bin/../../xCAT-server/lib/perl";
Because of those FindBin paths the tests only work from a source tree. The copy
installed under /opt/xcat/share/xcat/tools/autotest/unit is not a substitute --
../.. resolves to /opt/xcat/share/xcat/tools there and the tests die or silently
skip. The CI takes a copy of the checkout before the build for this reason; see
preserve_source_tree().
What does not belong here
Anything that needs an installed xCAT, a populated /install, a real service binary
or a live daemon. Those go in ../integration and run on
a management node through xcattest. Both suites run on every pull request -- the
workflow installs xCAT on the runner and then runs the ci_test cases against it --
so putting a test in integration/ does not cost it CI coverage. What differs is what
each suite is allowed to depend on, and that unit tests also run standalone from a
bare checkout with no xCAT at all.
Shell-script unit tests belong in ../bats
and run with BATS. Do not add Perl .t tests that grep shell source when the
behavior can be exercised by sourcing a shell library or script and shadowing the
external commands it calls.
The distinction matters because a test that needs an absent environment does not fail
-- it calls plan skip_all and reports as skipped. A handful of those in a suite of
several hundred assertions is easy to stop reading. Keeping the two kinds in separate
directories means a skip in unit/ is a real signal rather than routine noise.
Guarding on a source file, on the other hand, is fine and common here:
plan skip_all => "compute.subiquity.tmpl not found" unless -f $tmpl_path;
That guard never fires when the tree is intact.