add basic test for resource scheduling

currently only used to test the installed version and not
automatically during build. See the FIXME note for why.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>

pve-rs/test/Makefile

@@ -0,0 +1,4 @@
+.PHONY: test
+test:
+	@echo "-- running pve-rs tests --"
+	./resource_scheduling.pl

pve-rs/test/README

@@ -0,0 +1,2 @@
+Note that these tests are not run during build currently! See the FIXME note in
+resource_scheduling.pl for why.

pve-rs/test/resource_scheduling.pl

@@ -0,0 +1,70 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+# FIXME ensure that the just built library is loaded rather than the installed one and add a test
+# target to pve-rs/Makefile afterwards. Issue is that the loader looks into an $PATH/auto directory,
+# so it's not enough to use lib qw(../target/release)
+# Also might be a good idea to test for existence of the files to avoid surprises if the directory
+# structure changes in the future.
+#use lib qw(..);
+#use lib qw(../target/release);
+use PVE::RS::ResourceScheduling::Static;
+
+sub assert_num_eq {
+    my ($left, $right) = @_;
+    my (undef, undef, $line) = caller();
+    die "assertion failed: '$left != $right' at line $line\n" if $left != $right;
+}
+
+sub assert_str_eq {
+    my ($left, $right) = @_;
+    my (undef, undef, $line) = caller();
+    die "assertion failed: '$left ne $right' at line $line\n" if $left ne $right;
+}
+
+sub assert {
+    my ($bool) = @_;
+    my (undef, undef, $line) = caller();
+    die "assertion failed at line $line\n" if !$bool;
+}
+
+my $static = PVE::RS::ResourceScheduling::Static->new();
+assert_num_eq(scalar($static->list_nodes()->@*), 0);
+$static->add_node("A", 10, 100_000_000_000);
+assert_num_eq(scalar($static->list_nodes()->@*), 1);
+$static->add_node("B", 20, 200_000_000_000);
+assert_num_eq(scalar($static->list_nodes()->@*), 2);
+$static->add_node("C", 30, 300_000_000_000);
+assert_num_eq(scalar($static->list_nodes()->@*), 3);
+$static->remove_node("C");
+assert_num_eq(scalar($static->list_nodes()->@*), 2);
+assert($static->contains_node("A"));
+assert($static->contains_node("B"));
+assert(!$static->contains_node("C"));
+
+my $service = {
+    maxcpu => 4,
+    maxmem => 20_000_000_000,
+};
+
+for (my $i = 0; $i < 15; $i++) {
+    my $score_list = $static->score_nodes_to_start_service($service);
+
+    # imitate HA manager
+    my $scores = { map { $_->[0] => -$_->[1] } $score_list->@* };
+    my @nodes = sort {
+	$scores->{$a} <=> $scores->{$b} || $a cmp $b
+    } keys $scores->%*;
+
+    if ($i % 3 == 2) {
+	assert_str_eq($nodes[0], "A");
+	assert_str_eq($nodes[1], "B");
+    } else {
+	assert_str_eq($nodes[0], "B");
+	assert_str_eq($nodes[1], "A");
+    }
+
+    $static->add_service_usage_to_node($nodes[0], $service);
+}