Add support for OR and NOT filters

[cmurphy]

rancher/rancher#40141

OR filters

Currently, multiple filters can be appended on the query string, and each subsequent filter is ANDed with the set. Items that pass through the filter set must match every filter in the set.

This change adds support for OR filters. A single filter key can specify multiple filters, separated by ','. An item that passes this filter can match any filter in the set.

For example, this filter matches items that have either "name" or "namespace" that match "example":

?filter=metadata.name=example,metadata.namespace=example

This filter matches items that have "name" that matches either "foo" or "bar":

?filter=metadata.name=foo,metadata.name=bar

Specifying more than one filter key in the query still ANDs each inner filter set together. This set of filters can match either a name of "foo" or "bar", but must in all cases match namespace "abc":

?filter=metadata.name=foo,metadata.name=bar&filter=metadata.namespace=abc

NOT filters

This change adds support for excluding results using the != operator.

Example to exclude all results with name "example":

?filter=metadata.name!=example

Include all results from namespace "example" but exclude those with name
"example":

?filter=metadata.namespace=example&metadata.name!=example

Exclude results with name "foo" OR exclude results with name "bar"
(effectively includes results of both types):

?filter=metadata.name!=foo,metadata.name!=bar

[KevinJoiner]

Using a string builder is more efficient then concatenations.

Suggested change

	func (f OrFilter) String() string {
	fields := ""
	for i, field := range f.filters {
	fields += strings.Join(field.field, ".")
	fields += "=" + field.match
	if i < len(f.filters)-1 {
	fields += ","
	}
	}
	return fields
	}
	func (f OrFilter) String() string {
	fields := strings.Builder{}
	for i, field := range f.filters {
	fields.WriteString(strings.Join(field.field, "."))
	fields.WriteByte('=')
	fileds.WriteString(field.match)
	if i < len(f.filters)-1 {
	fields.WriteByte(',')
	}
	}
	return fields.String()
	}

[cmurphy]

👍

[KevinJoiner]

use strings.Builder

[cmurphy]

👍

[KevinJoiner]

nit: This doesn't have to be a struct, but this is just stylistic so you can ignore.

Suggested change

	type OrFilter struct {
	filters []Filter
	}
	type OrFilter []Filter

[cmurphy]

For me it makes more sense to think of the OrFilter as a container for one or more Filters, rather than as an alias for a list of filters, but you're right it would be the same.

[rmweir]

LGTM