[pve-devel] [RFC common] fix misleading warning caused by Devel::Cycle
Stoiko Ivanov
s.ivanov at proxmox.com
Fri Nov 22 18:21:08 CET 2019
When validating the parameters (or return values) of an API call against the
schema we run the parameter hash through Devel::Cycle::find_cycle.
find_cycle has no handler for GLOB types (e.g. filehandles).
Recently we introduced passing a filehandle as return attribute in
PMG::API2::Quarantine::download
When find_cycle encounters such an object it emits a warning:
`Unhandled type: GLOB at /usr/share/perl5/Devel/Cycle.pm line 109`
which ends up in the journal of pmgproxy (in that example).
Since the line might mislead someone to think that this is a more serious bug
we silence it, by overriding the warnhandler ($SIG{'__WARN__'}, [0,1]) for the
time when find_cycle runs, to ignore messages starting with
'Unhandled type: GLOB at'. The particular location of and in in Devel::Cycle
might change and is left out of the match.
[0] man perlvar
[1] perldoc -f warn
Signed-off-by: Stoiko Ivanov <s.ivanov at proxmox.com>
---
sending as RFC, since the comment above the patch already indicate that we
could do away with the cycle-search on every call
The choice of saving the old handler and restoring it instead of using
local $SIG{'__WARN__'} was done to minimize the effect - although local'izing
is a bit more idiomatic it seems.
Caught this in my PMG's journal - traced it down, by editing
/usr/share/perl5/Devel/Cycle and adding a Carp::cluck at the location the
warning came from)
at /usr/share/perl5/Devel/Cycle.pm line 108.
Devel::Cycle::_find_cycle_dispatch(IO::File=GLOB(0x559b8b002420), HASH(0x559b8ad928b8), CODE(0x559b8acfe4f0), 0, HASH(0x559b8ad36c40), ARRAY(0x559b8acfd088)) called at /usr/share/perl5/Devel/Cycle.pm line 97
Devel::Cycle::_find_cycle(IO::File=GLOB(0x559b8b002420), HASH(0x559b8b0b6c80), CODE(0x559b8acfe4f0), 0, HASH(0x559b8ad36c40), ARRAY(0x559b8acfd088)) called at /usr/share/perl5/Devel/Cycle.pm line 156
Devel::Cycle::_find_cycle_HASH(HASH(0x559b8b002450), HASH(0x559b8ad8d088), CODE(0x559b8acfe4f0), 0, HASH(0x559b8ad36c40)) called at /usr/share/perl5/Devel/Cycle.pm line 114
Devel::Cycle::_find_cycle_dispatch(HASH(0x559b8b002450), HASH(0x559b8ad8d088), CODE(0x559b8acfe4f0), 0, HASH(0x559b8ad36c40)) called at /usr/share/perl5/Devel/Cycle.pm line 97
Devel::Cycle::_find_cycle(HASH(0x559b8b002450), HASH(0x559b87def760), CODE(0x559b8acfe4f0), 0, HASH(0x559b8ad36c40)) called at /usr/share/perl5/Devel/Cycle.pm line 70
Devel::Cycle::find_cycle(HASH(0x559b8b002450), CODE(0x559b8acfe4f0)) called at /usr/share/perl5/PVE/JSONSchema.pm line 1053
PVE::JSONSchema::validate(HASH(0x559b8b002450), HASH(0x559b8ab6d330), "Result verification failed\x{a}") called at /usr/share/perl5/PVE/RESTHandler.pm line 449
PVE::RESTHandler::handle("PMG::API2::Quarantine", HASH(0x559b8ab6d738), HASH(0x559b8ad23c10)) called at /usr/share/perl5/PMG/HTTPServer.pm line 157
eval {...} called at /usr/share/perl5/PMG/HTTPServer.pm line 111
PMG::HTTPServer::rest_handler(PMG::HTTPServer=HASH(0x559b8ac60ad8), "192.168.16.68", "GET", "/quarantine/download", HASH(0x559b8acc0300), HASH(0x559b8706b9c8), "json") called at /usr/share/perl5/PVE/APIServer/AnyEvent.pm line 725
eval {...} called at /usr/share/perl5/PVE/APIServer/AnyEvent.pm line 699
PVE::APIServer::AnyEvent::handle_api2_request(PMG::HTTPServer=HASH(0x559b8ac60ad8), HASH(0x559b8708f268), HASH(0x559b8acc0300), "GET", "/api2/json/quarantine/download") called at /usr/share/perl5/PVE/APIServer/AnyEvent.pm line 950
eval {...} called at /usr/share/perl5/PVE/APIServer/AnyEvent.pm line 942
PVE::APIServer::AnyEvent::handle_request(PMG::HTTPServer=HASH(0x559b8ac60ad8), HASH(0x559b8708f268), HASH(0x559b8acc0300), "GET", "/api2/json/quarantine/download") called at /usr/share/perl5/PVE/APIServer/AnyEvent.pm line 1342
eval {...} called at /usr/share/perl5/PVE/APIServer/AnyEvent.pm line 1160
PVE::APIServer::AnyEvent::__ANON__(AnyEvent::Handle=HASH(0x559b87057838), "", "\x{d}\x{a}") called at /usr/lib/x86_64-linux-gnu/perl5/5.28/AnyEvent/Handle.pm line 1541
AnyEvent::Handle::__ANON__(AnyEvent::Handle=HASH(0x559b87057838)) called at /usr/lib/x86_64-linux-gnu/perl5/5.28/AnyEvent/Handle.pm line 1315
AnyEvent::Handle::_drain_rbuf(AnyEvent::Handle=HASH(0x559b87057838)) called at /usr/lib/x86_64-linux-gnu/perl5/5.28/AnyEvent/Handle.pm line 2100
AnyEvent::Handle::_dotls(AnyEvent::Handle=HASH(0x559b87057838)) called at /usr/lib/x86_64-linux-gnu/perl5/5.28/AnyEvent/Handle.pm line 2013
AnyEvent::Handle::__ANON__(EV::IO=SCALAR(0x559b8acbfcd0), 1) called at /usr/lib/x86_64-linux-gnu/perl5/5.28/AnyEvent/Impl/EV.pm line 88
eval {...} called at /usr/lib/x86_64-linux-gnu/perl5/5.28/AnyEvent/Impl/EV.pm line 88
AnyEvent::CondVar::Base::_wait(AnyEvent::CondVar=HASH(0x559b8708f8b0)) called at /usr/lib/x86_64-linux-gnu/perl5/5.28/AnyEvent.pm line 2026
AnyEvent::CondVar::Base::recv(AnyEvent::CondVar=HASH(0x559b8708f8b0)) called at /usr/share/perl5/PVE/APIServer/AnyEvent.pm line 1623
PVE::APIServer::AnyEvent::run(PMG::HTTPServer=HASH(0x559b8ac60ad8)) called at /usr/share/perl5/PMG/Service/pmgproxy.pm line 132
PMG::Service::pmgproxy::run(PMG::Service::pmgproxy=HASH(0x559b8ac1ca00)) called at /usr/share/perl5/PVE/Daemon.pm line 171
eval {...} called at /usr/share/perl5/PVE/Daemon.pm line 171
PVE::Daemon::__ANON__(PMG::Service::pmgproxy=HASH(0x559b8ac1ca00)) called at /usr/share/perl5/PVE/Daemon.pm line 391
eval {...} called at /usr/share/perl5/PVE/Daemon.pm line 380
PVE::Daemon::__ANON__(PMG::Service::pmgproxy=HASH(0x559b8ac1ca00), 1) called at /usr/share/perl5/PVE/Daemon.pm line 552
eval {...} called at /usr/share/perl5/PVE/Daemon.pm line 550
PVE::Daemon::start(PMG::Service::pmgproxy=HASH(0x559b8ac1ca00), 1) called at /usr/share/perl5/PVE/Daemon.pm line 660
PVE::Daemon::__ANON__(HASH(0x559b8543fbd8)) called at /usr/share/perl5/PVE/RESTHandler.pm line 446
PVE::RESTHandler::handle("PMG::Service::pmgproxy", HASH(0x559b8ac4bf68), HASH(0x559b8543fbd8)) called at /usr/share/perl5/PVE/RESTHandler.pm line 855
eval {...} called at /usr/share/perl5/PVE/RESTHandler.pm line 838
PVE::RESTHandler::cli_handler("PMG::Service::pmgproxy", "pmgproxy start", "start", ARRAY(0x559b8574f330), ARRAY(0x559b8ac55bc0), undef, undef, undef) called at /usr/share/perl5/PVE/CLIHandler.pm line 590
PVE::CLIHandler::__ANON__(ARRAY(0x559b8543ff38), CODE(0x559b85489128), undef) called at /usr/share/perl5/PVE/CLIHandler.pm line 667
PVE::CLIHandler::run_cli_handler("PMG::Service::pmgproxy", "prepare", CODE(0x559b85489128)) called at /usr/bin/pmgproxy line 31
src/PVE/JSONSchema.pm | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/src/PVE/JSONSchema.pm b/src/PVE/JSONSchema.pm
index 51c3881..6954241 100644
--- a/src/PVE/JSONSchema.pm
+++ b/src/PVE/JSONSchema.pm
@@ -1038,8 +1038,22 @@ sub validate {
# todo: cycle detection is only needed for debugging, I guess
# we can disable that in the final release
# todo: is there a better/faster way to detect cycles?
+
+ # override warn handler to suppress log-messages for e.g. File::IO objects
+ # in the API definitions (e.g. PMG::API2::Quarantine::download)
+ my $oldwarn = $SIG{'__WARN__'};
+ $SIG{'__WARN__'} = sub {
+ my ($warn) = @_;
+ if ($warn !~ /^Unhandled type: GLOB at/) {
+ print STDERR "$warn\n";
+ }
+ };
+
my $cycles = 0;
find_cycle($instance, sub { $cycles = 1 });
+
+ $SIG{'__WARN__'} = $oldwarn;
+
if ($cycles) {
add_error($errors, undef, "data structure contains recursive cycles");
} elsif ($schema) {
--
2.20.1
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