Require GruTask in database before running a minion job

It can happen that a GruTasks entry is added in a transaction and the minion
job already enqueued and started before the transaction is committed.

In that case we shouldn't start the minion job (the transaction could have
been rollbacked even).

The task needs to be deleted by the minion job in order to go on with
processing a job, and it can't delete it if it doesn't see the entry in the
database.

But requiring the entry before the start of the job is even more correct IMHO.

Issue: https://progress.opensuse.org/issues/165866

lib/OpenQA/Shared/GruJob.pm

@@ -10,6 +10,12 @@ sub execute {
     my $self = shift;
 
     my $gru_id = $self->info->{notes}{gru_id};
+    if ($gru_id and not $self->info->{finished}) {
+        # We have a gru_id and this is the first run of the job
+        my $gru = $self->minion->app->schema->resultset('GruTasks')->find($gru_id);
+        # GruTask might not yet have landed in database due to open transaction
+        return $self->retry({delay => 2}) unless $gru;
+    }
     my $err = $self->SUPER::execute;
 
     # Non-Gru tasks

t/14-grutasks.t

@@ -127,6 +127,7 @@ $t->app->minion->add_task(
         return $job->retry({delay => 30})
           unless my $guard = $job->minion->guard('limit_gru_retry_task', ONE_HOUR);
     });
+$t->app->minion->add_task(wait_for_grutask => sub (@) { undef });
 
 # Gru task that reached failed/finished manually
 # uncoverable statement
@@ -574,6 +575,18 @@ subtest 'Gru tasks retry' => sub {
     is $t->app->minion->job($ids->{minion_id})->info->{state}, 'finished', 'minion job is finished';
 };
 
+subtest 'waiting gru job' => sub {
+    my $enq = $app->gru->enqueue(wait_for_grutask => {});
+    # Simulate that the gru task is not yet visible for the minion server
+    $schema->resultset('GruTasks')->find($enq->{gru_id})->delete;
+    my $worker = $app->minion->worker->register;
+    my $job = $worker->dequeue(0, {id => $enq->{minion_id}});
+    $job->execute;
+    is $job->info->{retries}, 1, 'job retried because there is no GruTasks entry';
+    is $job->info->{state}, 'inactive', 'state inactive because there is no GruTasks entry';
+    is $job->info->{finished}, undef, 'finished is not defined';
+};
+
 # prevent writing to a log file to enable use of combined_like in the following tests
 $t->app->log(Mojo::Log->new(level => 'debug'));