[#26] schema: Add resource name validation method

Close #26

Signed-off-by: Airat Arifullin <aarifullin@yadro.com>

docs/resource.md

@@ -0,0 +1,20 @@
+# Resource
+
+From the point of the access policy engine, a resource is an object to which a request is being performed. 
+This can be an object in a container within a namespace, or all objects in a container,
+or all containers within the root namespace etc.
+
+A resource can be viewed from two sides:
+ - As part of a [request](../pkg/resource/resource.go). In this case a resource has a name and properties.
+ - As part of rule [chain](../pkg/chain/chain.go): a resource has just a name.
+
+## Resource name
+
+A resource name must have a such format that can be processed by a chain router that matches a request
+either with local overrides or with rules within policy contract to get if this request is allowed to be performed.
+The main idea of this format is for the chain router to match by full name (`native:object//cnrID/objID`) or
+wildcard (`native:object//cnrID/*`).
+
+Check out formats that are defined in the schema: [native formats](../schema/native/consts.go), [s3 formats](../schema/s3/consts.go).
+You should validate a resource name using [util](../schema/native/util/validation.go) before instantiating a request or
+before putting it to either to local override storage or the policy contract storage.

schema/native/util/validation.go

@@ -0,0 +1,45 @@
+package util
+
+import (
+	"strings"
+
+	"git.frostfs.info/TrueCloudLab/policy-engine/schema/native"
+)
+
+var nativePatterns = []string{
+	native.ResourceFormatNamespaceObjects, native.ResourceFormatNamespaceContainerObjects,
+	native.ResourceFormatNamespaceContainerObject, native.ResourceFormatRootObjects,
+	native.ResourceFormatRootContainerObjects, native.ResourceFormatRootContainerObject,
+	native.ResourceFormatAllObjects, native.ResourceFormatNamespaceContainer,
+	native.ResourceFormatNamespaceContainers, native.ResourceFormatRootContainer,
+	native.ResourceFormatRootContainers, native.ResourceFormatAllContainers,
+}
+
+func match(resource, pattern string) bool {
+	rTokens := strings.Split(resource, "/")
+	pToken := strings.Split(pattern, "/")
+
+	if len(rTokens) != len(pToken) {
+		return false
+	}
+
+	for i := range rTokens {
+		if pToken[i] == "%s" {
+			continue
+		}
+		if pToken[i] != rTokens[i] {
+			return false
+		}
+	}
+
+	return true
+}
+
+func IsNativeResourceNameValid(resource string) bool {
+	for _, pattern := range nativePatterns {
+		if match(resource, pattern) {
+			return true
+		}
+	}
+	return false
+}

schema/native/util/validation_test.go

@@ -0,0 +1,97 @@
+package util
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+var tests = []struct {
+	name     string
+	expected bool
+	resource string
+}{
+	{
+		name:     "ResourceFormatNamespaceObjects",
+		expected: true,
+		resource: "native:object/RootNamespace/*",
+	},
+	{
+		name:     "ResourceFormatNamespaceContainerObjects",
+		expected: true,
+		resource: "native:object/RootNamespace/BzQw5HH3feoxFDD5tCT87Y1726qzgLfxEE7wgtoRzB3R/*",
+	},
+	{
+		name:     "ResourceFormatNamespaceContainerObject",
+		expected: true,
+		resource: "native:object/RootNamespace/BzQw5HH3feoxFDD5tCT87Y1726qzgLfxEE7wgtoRzB3R/AeZa5HH3feoxFDD5tCT87Y1726qzgLfxEE7wgtoRzB4E",
+	},
+	{
+		name:     "ResourceFormatRootObjects",
+		expected: true,
+		resource: "native:object//*",
+	},
+	{
+		name:     "ResourceFormatRootContainerObjects",
+		expected: true,
+		resource: "native:object//BzQw5HH3feoxFDD5tCT87Y1726qzgLfxEE7wgtoRzB3R/*",
+	},
+	{
+		name:     "ResourceFormatRootContainerObject",
+		expected: true,
+		resource: "native:object//BzQw5HH3feoxFDD5tCT87Y1726qzgLfxEE7wgtoRzB3R/AeZa5HH3feoxFDD5tCT87Y1726qzgLfxEE7wgtoRzB4E",
+	},
+	{
+		name:     "ResourceFormatAllObjects",
+		expected: true,
+		resource: "native:object/*",
+	},
+	{
+		name:     "ResourceFormatNamespaceContainer",
+		expected: true,
+		resource: "native:container/RootNamespace/BzQw5HH3feoxFDD5tCT87Y1726qzgLfxEE7wgtoRzB3R",
+	},
+	{
+		name:     "ResourceFormatNamespaceContainers",
+		expected: true,
+		resource: "native:container/RootNamespace/*",
+	},
+	{
+		name:     "ResourceFormatRootContainers",
+		expected: true,
+		resource: "native:container//*",
+	},
+	{
+		name:     "ResourceFormatAllContainers",
+		expected: true,
+		resource: "native:container/*",
+	},
+	{
+		name:     "Invalid resource 1",
+		expected: false,
+		resource: "native:::container/*",
+	},
+	{
+		name:     "Invalid resource 2",
+		expected: false,
+		resource: "native:container/RootNamespace/w5HH3feoxFDD5tCTtoRzB3R/Bz726qzgLfxEE7wgtoRzB3R/RootNamespace",
+	},
+}
+
+func TestIsNativeResourceNameValid(t *testing.T) {
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			require.Equal(t, test.expected, IsNativeResourceNameValid(test.resource))
+		})
+	}
+}
+
+func BenchmarkIsNativeResourceNameValid(b *testing.B) {
+	for _, test := range tests {
+		b.Run(test.name, func(b *testing.B) {
+			for i := 0; i < b.N; i++ {
+				_ = IsNativeResourceNameValid(test.resource)
+			}
+		})
+	}
+}