Validate key existence before proceeding

lib/OpenQA/WebAPI/Plugin/ObsRsync.pm

@@ -532,7 +532,7 @@ sub _for_every_batch {
 
 # Based on https://www.suse.com/c/multi-factor-authentication-on-suses-build-service/
 sub _bs_ssh_sign ($key, $realm, $value) {
-
+    die "SSH Key File not found at $key" unless (-e $key || -z $key);
     # This needs to be a bit portable for CI testing
     my $tmp = Mojo::File::tempfile->spew($value);
     my @lines = split "\n", qx/ssh-keygen -Y sign -f "$key" -q -n "$realm" < $tmp/;

t/ui/27-plugin_obs_rsync_obs_status.t

@@ -214,11 +214,11 @@ $t->get_ok('/admin/obs_rsync/queue')->status_is(200, 'jobs list')->content_like(
 $t->get_ok('/admin/obs_rsync/')->status_is(200, 'project list')->content_like(qr/published/)->content_like(qr/dirty/)
   ->content_like(qr/publishing/);
 
-subtest 'test build service ssh authentication' => sub {
+subtest 'build service ssh authentication' => sub {
     is($helper->is_status_dirty('ProjWithAuth'), 1, 're-authenticate with ssh auth');
 };
 
-subtest 'test build service authentication signature generation' => sub {
+subtest 'build service authentication: signature generation' => sub {
     $mocked_time = 1664187470;
     note "time right now: " . time();
 
@@ -228,6 +228,20 @@ subtest 'test build service authentication signature generation' => sub {
     $mocked_time = undef;
 };
 
+subtest 'build service authentication: error handling' => sub {
+    $ssh_keyfile->remove();
+    throws_ok {
+        $helper->is_status_dirty('ProjTestingSignature')
+    }
+    qr/SSH Key File not found at/, 'Unexpected key detected';
+
+    $ssh_keyfile->touch();
+    throws_ok {
+        $helper->is_status_dirty('ProjTestingSignature')
+    }
+    qr/SSH Key File not found at/, 'Unexpected key detected';
+};
+
 $server_instance->stop;
 done_testing();