Re: [pve-devel] [RFC PATCH common] section config: implement array support

["Fabian Grünbichler" <f.gruenbichler@proxmox.com>]

On May 10, 2023 10:18 am, Dominik Csapak wrote:
> enables section configs in the style of:
> 
> ----
> type: id
>     property value
>     property value2
>     property value3
> ----
> 
> can be combined with property strings
> 
> the provided createSchema just uses the name of the property but the
> schema of the inner item
> 
> the api call is supposed to check if the overall entry of the section
> config already exists and if yes, insert a new entry into the array
> 
> the updateSchema works very similar, but has the following addition:
> 
> if it's not a property string, there is an extra 'X-index' parameter
> that indicates the index of the element to be updated (for property
> strings, the api call has to figure out which entry to update, but there
> we have most likely something resembling an id anyway)
> 
> for deletion, we don't provide a schema generator, but a good approach
> would be to have optional parameters for the array id/index and only
> deleting the relevant array entries then

in PBS/Rust, an optional array (Vec) type gets a wholesale updater
derived (SyncJobConfig has one, POM config as well).

> also adds a test case for such array fields
> 
> Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
> ---
> another idea i had with the schemas was to extract the seperate options
> of the property string into the api, but that was weird for the
> following reasons:
> 
> * it's asymmetric if we don't automatically use print_property_string or
> * we'd have to parse those directly with parse_property_string
>   (that would be a major change, since all users that use non-array
>   property strings don't expect that)
> * or have it inconsistent between non-array and array property
>   strings...
> 
> this way we get a property string from the api and the config parsing,
> and the config writer expects property strings, so easy to implement and
> consistent, for the cost of having all api calls use parse/print
> manually (which won't be that many hopefully)
> 
>  src/PVE/SectionConfig.pm    | 88 ++++++++++++++++++++++++++++++-------
>  test/section_config_test.pl | 26 +++++++++++
>  2 files changed, 98 insertions(+), 16 deletions(-)
> 
> diff --git a/src/PVE/SectionConfig.pm b/src/PVE/SectionConfig.pm
> index f36cede..baace66 100644
> --- a/src/PVE/SectionConfig.pm
> +++ b/src/PVE/SectionConfig.pm
> @@ -51,6 +51,17 @@ sub plugindata {
>      return {};
>  }
>  
> +my $copy_property = sub {
> +    my ($src) = @_;
> +
> +    my $res = {};
> +    foreach my $k (keys %$src) {
> +	$res->{$k} = $src->{$k};
> +    }
> +
> +    return $res;
> +};
> +
>  sub createSchema {
>      my ($class, $skip_type) = @_;
>  
> @@ -60,20 +71,15 @@ sub createSchema {
>  
>      my $props = {};
>  
> -    my $copy_property = sub {
> -	my ($src) = @_;
> -
> -	my $res = {};
> -	foreach my $k (keys %$src) {
> -	    $res->{$k} = $src->{$k};
> -	}
> -
> -	return $res;
> -    };
> -
>      foreach my $p (keys %$propertyList) {
>  	next if $skip_type && $p eq 'type';
>  
> +	if ($propertyList->{$p}->{type} eq 'array') {
> +	    $props->{$p} = $copy_property->($propertyList->{$p}->{items});
> +	    $props->{$p}->{optional} = $propertyList->{$p}->{optional} // 0;

is this congruent with the rust SectionConfig schema? IIRC there were
some extra checks there w.r.t. keys set both on the array and the item?

> +	    next;
> +	}
> +
>  	if (!$propertyList->{$p}->{optional}) {
>  	    $props->{$p} = $propertyList->{$p};
>  	    next;
> @@ -124,6 +130,24 @@ sub updateSchema {
>  
>  	next if defined($filter_type) && !defined($copts->{$p});
>  
> +	if ($propertyList->{$p}->{type} eq 'array') {
> +	    $props->{$p} = $copy_property->($propertyList->{$p}->{items});
> +	    $props->{$p}->{optional} = $propertyList->{$p}->{optional} // 0;
> +
> +	    # add index for all non property strings
> +	    if (!defined($propertyList->{$p}->{items}->{format})) {
> +		$props->{$p}->{requires} = "$p-index";
> +		$props->{"$p-index"} = {
> +		    type => 'integer',
> +		    minimum => 0,
> +		    description => "Determines which array element to update (0 is the first element).",
> +		    optional => $propertyList->{$p}->{optional} // 0,
> +		},

this is not how it's implemented in our Rust schema..

I guess we could make the index optional always and implement similar
support on the rust side as well? no index -> wholesale replacement.
index -> partial update? if we do partial updaters for arrays, it would
also be nice to have them for property strings as well (although that is
of course more work to implement, but it would have more potential for
UX improvement) - a property string is just an object after all, so the
key is the "index".

> +	    }
> +
> +	    next;
> +	}
> +
>  	if (!$propertyList->{$p}->{optional}) {
>  	    $props->{$p} = $propertyList->{$p};
>  	    next;
> @@ -254,7 +278,15 @@ sub check_value {
>  
>      if (!$skipSchemaCheck) {
>  	my $errors = {};
> -	PVE::JSONSchema::check_prop($value, $schema, '', $errors);
> +
> +	my $checkschema = $schema;
> +
> +	if ($ct eq 'array') {
> +	    die "no item schema for array" if !defined($schema->{items});
> +	    $checkschema = $schema->{items};
> +	}
> +
> +	PVE::JSONSchema::check_prop($value, $checkschema, '', $errors);
>  	if (scalar(keys %$errors)) {
>  	    die "$errors->{$key}\n" if $errors->{$key};
>  	    die "$errors->{_root}\n" if $errors->{_root};
> @@ -311,6 +343,15 @@ sub parse_config {
>  	}
>      };
>  
> +    my $is_array = sub {
> +	my ($type, $key) = @_;
> +
> +	my $schema = $pdata->{propertyList}->{$key};
> +	die "unknown property type\n" if !$schema;
> +
> +	return $schema->{type} eq 'array';
> +    };
> +
>      my $errors = [];
>      while (@lines) {
>  	my $line = $nextline->();
> @@ -352,11 +393,19 @@ sub parse_config {
>  		    my ($k, $v) = ($1, $3);
>  
>  		    eval {
> -			die "duplicate attribute\n" if defined($config->{$k});
> -			if (!$unknown) {
> -			    $v = $plugin->check_value($type, $k, $v, $sectionId);
> +			if ($is_array->($type, $k)) {
> +			    if (!$unknown) {
> +				$v = $plugin->check_value($type, $k, $v, $sectionId);
> +			    }
> +			    $config->{$k} = [] if !defined($config->{$k});
> +			    push $config->{$k}->@*, $v;
> +			} else {
> +			    die "duplicate attribute\n" if defined($config->{$k});
> +			    if (!$unknown) {
> +				$v = $plugin->check_value($type, $k, $v, $sectionId);
> +			    }
> +			    $config->{$k} = $v;
>  			}
> -			$config->{$k} = $v;
>  		    };
>  		    if (my $err = $@) {
>  			warn "$errprefix (section '$sectionId') - unable to parse value of '$k': $err";
> @@ -448,6 +497,13 @@ my $format_config_line = sub {
>      if ($ct eq 'boolean') {
>  	return "\t$key " . ($value ? 1 : 0) . "\n"
>  	    if defined($value);
> +    } elsif ($ct eq 'array') {
> +	die "property '$key' is not an array" if ref($value) ne 'ARRAY';
> +	my $result = '';
> +	for my $line ($value->@*) {
> +	    $result .= "\t$key $line\n" if $value ne '';

should this here encode the value of each item according to the item
type? e.g., recursively call format_config_line again with the item
schema?

> +	}
> +	return $result;
>      } else {
>  	return "\t$key $value\n" if "$value" ne '';
>      }
> diff --git a/test/section_config_test.pl b/test/section_config_test.pl
> index 22a9643..fc20e4c 100755
> --- a/test/section_config_test.pl
> +++ b/test/section_config_test.pl
> @@ -105,6 +105,25 @@ sub properties {
>  	    minimum => 3,
>  	    maximum => 9,
>  	},
> +	arrayfield => {
> +	    descritpion => "Array Field with property string",
> +	    type => 'array',
> +	    items => {
> +		type => 'string',
> +		descritpion => 'a property string',

nit: description spelled wrong here and below ;)

> +		format => {
> +		    subfield1 => {
> +			type => 'string',
> +			descritpion => 'first subfield'
> +		    },
> +		    subfield2 => {
> +			type => 'integer',
> +			minimum => 0,
> +			optional => 1,
> +		    },
> +		},
> +	    },
> +	},
>      };
>  }
>  
> @@ -113,6 +132,7 @@ sub options {
>  	common => { optional => 1 },
>  	field2 => {},
>  	another => {},
> +	arrayfield => { optional => 1 },
>      };
>  }
>  
> @@ -190,6 +210,10 @@ my $with_unknown_data = {
>  	    type => 'two',
>  	    field2 => 5,
>  	    another => 'even more text',
> +	    arrayfield => [
> +		'subfield1=test,subfield2=2',
> +		'subfield1=test2',
> +	    ],
>  	},
>  	invalid => {
>  	    type => 'bad',
> @@ -214,6 +238,8 @@ bad: invalid
>  two: t3
>  	field2 5
>  	another even more text
> +	arrayfield subfield1=test,subfield2=2
> +	arrayfield subfield1=test2
>  EOF
>  
>  Conf->expect_fail('unknown-forbidden', $with_unknown_data, $with_unknown_text);
> -- 
> 2.30.2
> 
> 
> 
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