[pve-devel] [PATCH ha-manager v2 06/26] rules: add global checks between location and colocation rules

[Michael Köppl]

On 6/20/25 16:31, Daniel Kral wrote:
> Add checks, which determine infeasible colocation rules, because their
> services are already restricted by their location rules in such a way,
> that these cannot be satisfied or are reasonable to be proven to be
> satisfiable.
> 
> Positive colocation rule services need to have at least one common node
> to be feasible and negative colocation rule services need to have at
> least the amount of nodes available that nodes are restricted to in
> total, i.e. services that are in strict location rules.
> 
> Since location rules allow nodes to be put in priority groups, but the
> information which priority group is relevant depends on the online
> nodes, these checks currently prohibit colocation rules with services,
> which make use of these kinds of location rules.
> 
> Even though location rules are restricted to only allow a service to be
> used in a single location rule, the checks here still go over all
> location rules, as this restriction is bound to be changed in the
> future.
> 
> Signed-off-by: Daniel Kral <d.kral at proxmox.com>
> ---
> changes since v1:
>     - moved global checks from Colocation plugin to base plugin
>     - add check to only allow colocation rules for services which are in
>       single-priority location rules / ha groups because these are quite
>       stateful and cannot be easily verified to be possible
> 
>  src/PVE/HA/Rules.pm | 189 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 189 insertions(+)
> 
> diff --git a/src/PVE/HA/Rules.pm b/src/PVE/HA/Rules.pm
> index 4134283..588e53b 100644
> --- a/src/PVE/HA/Rules.pm
> +++ b/src/PVE/HA/Rules.pm
> @@ -3,6 +3,7 @@ package PVE::HA::Rules;
>  use strict;
>  use warnings;
>  
> +use PVE::HashTools;
>  use PVE::JSONSchema qw(get_standard_option);
>  use PVE::Tools;
>  
> @@ -469,4 +470,192 @@ sub foreach_rule : prototype($$;$) {
>      }
>  }
>  
> +=head1 INTER-PLUGIN RULE CHECKERS
> +
> +=cut
> +
> +=head3 check_single_priority_location_for_colocated_services($location_rules, $colocation_rules)
> +
> +Returns a list of colocation rule ids defined in C<$colocation_rules>, where
> +the services in the colocation rule are in location rules, defined in
> +C<$location_rules>, which have multiple priority groups defined. That is, the
> +colocation rule cannot be statically checked to be feasible as the selection of
> +the priority group is dependent on the currently online nodes.

Might be that I'm misinterpreting this, but doesn't that only apply when
the location rule contains more than 1 node? At the moment, this check
would fail if I have location rules vm:100->node1 and vm:101->node2,
either of them has a priority assigned and I then try to add a
colocation rule that separates them. This would be possible without the
priority assigned.

> +
> +If there are none, the returned list is empty.
> +
> +=cut
> +
> +sub check_single_priority_location_for_colocated_services {
> +    my ($colocation_rules, $location_rules) = @_;
> +
> +    my @errors = ();
> +
> +    while (my ($colocationid, $colocation_rule) = each %$colocation_rules) {
> +        my $priority;
> +        my $services = $colocation_rule->{services};
> +
> +        for my $locationid (keys %$location_rules) {
> +            my $location_rule = $location_rules->{$locationid};
> +
> +            next if PVE::HashTools::sets_are_disjoint($services, $location_rule->{services});
> +
> +            for my $node (values %{ $location_rule->{nodes} }) {
> +                $priority = $node->{priority} if !defined($priority);
> +
> +                if ($priority != $node->{priority}) {
> +                    push @errors, $colocationid;
> +                    last; # early return to check next colocation rule
> +                }
> +            }
> +        }
> +    }
> +