Re: [RFC pve-common v2 02/17] jsonschema: support 'patternProperties' and allow 'x-' keywords

[Jakob Klocker <j.klocker@proxmox.com>]

comments inline

On 7/17/26 5:49 PM, Max R. Carrara wrote:
> by adding the necessary validation code before the
> `additionalProperties` handling in `check_object()` and extending the
> default schema (the schema for JSON schemas).
> 
> At the same time, allow all keywords beginning with 'x-' to be
> included in a given schema. This makes it possible specify custom
> extension keywords that can be used for e.g. hints, flags, and other
> things.
> 
> Signed-off-by: Max R. Carrara <m.carrara@proxmox.com>
> ---
> NOTE: This patch is experimental and thus marked as RFC.
> 
>  src/PVE/JSONSchema.pm    | 61 +++++++++++++++++++++++++++++++++++-----
>  test/json-schema-test.pl |  2 +-
>  2 files changed, 55 insertions(+), 8 deletions(-)
> 
> diff --git a/src/PVE/JSONSchema.pm b/src/PVE/JSONSchema.pm
> index 49f6aa6..1bfa5f6 100644
> --- a/src/PVE/JSONSchema.pm
> +++ b/src/PVE/JSONSchema.pm
> @@ -1073,6 +1073,9 @@ sub parse_property_string {
>      # In property strings we default to not allowing additional properties
>      $additional_properties = 0 if !defined($additional_properties);
> 
> +    # In property strings we do not allow pattern properties at all
> +    my $pattern_properties = 0;
> +
>      # Support named formats here, too:
>      my $validator;
>      if (!ref($format)) {
> @@ -1141,7 +1144,7 @@ sub parse_property_string {
>      }
> 
>      my $errors = {};
> -    check_object($path, $format, $res, $additional_properties, $errors);
> +    check_object($path, $format, $res, $pattern_properties, $additional_properties, $errors);
>      if (scalar(%$errors)) {
>          raise "format error\n", errors => $errors;
>      }
> @@ -1294,7 +1297,7 @@ my sub get_instance_type {
>  }
> 
>  sub check_object {
> -    my ($path, $schema, $value, $additional_properties, $errors) = @_;
> +    my ($path, $schema, $value, $pattern_properties, $additional_properties, $errors) = @_;
> 
>      # print "Check Object " . Dumper($value) . "\nSchema: " . Dumper($schema);
> 
> @@ -1367,6 +1370,23 @@ sub check_object {
>              next if $matched_type; # value is already checked above
>          }
> 
> +        if (defined($pattern_properties) && $pattern_properties) {

checking if the variable is defined and then the variable itself seems
redundant - if `$pattern_properties` is undef the `if` check would be
false anyway
> +            my $has_err = 0;
> +            my $pattern_schema = undef;
> +
> +            for my $pattern (keys $pattern_properties->%*) {
> +                if ($k =~ $pattern) {
> +                    $pattern_schema = $pattern_properties->{$pattern};
> +                    last;
> +                }
> +            }
> +
> +            next if $has_err;

`$has_err` is initialized to 0 and never changed, so this next is dead
code. Was it meant to handle the case where no pattern matches $k?
> +
> +            check_prop($value->{$k}, $pattern_schema, $newpath, $errors);
> +            next;
> +        }
> +
>          if (defined($additional_properties) && !$additional_properties) {
>              add_error(
>                  $errors,
[snip]