add(system): resource and service validation

system/service/permissions.go

@@ -0,0 +1,57 @@
+package service
+
+import (
+	"strings"
+
+	"github.com/pkg/errors"
+)
+
+func validateResource(resource string) error {
+	delimiter := ":"
+
+	resources := map[string]bool{
+		"messaging:channel": true,
+	}
+
+	if result := resources[resource]; result {
+		return nil
+	}
+
+	resourceParts := strings.Split(resource, delimiter)
+	if len(resourceParts) != 3 {
+		return errors.Errorf("Invalid resource format, expected 3, got %d", len(resourceParts))
+	}
+
+	for prefix := range resources {
+		prefix = prefix + delimiter
+		if len(resource) < len(prefix)+1 {
+			continue
+		}
+		if resource[:len(prefix)] == prefix {
+			return nil
+		}
+	}
+
+	return errors.Errorf("Invalid resource name, '%s'", resource)
+}
+
+func validatePermission(service string, resource string, operation string) error {
+	var services = map[string]map[string]bool{
+		"messaging": map[string]bool{
+			"manage.webhooks":    false,
+			"message.send":       true,
+			"message.embed":      true,
+			"message.attach":     true,
+			"message.update_own": true,
+			"message.update_all": true,
+			"message.react":      true,
+		},
+	}
+	if service, ok := services[service]; ok {
+		if op := service[operation]; op {
+			return validateResource(resource)
+		}
+		return errors.Errorf("Unknown operation: '%s'", operation)
+	}
+	return errors.Errorf("Unknown service name: '%s'", service)
+}

system/service/permissions_test.go

@@ -0,0 +1,15 @@
+package service
+
+import (
+	"testing"
+
+	"github.com/crusttech/crust/internal/test"
+)
+
+func TestPermissionsValidation(t *testing.T) {
+	test.Error(t, validatePermission("bogus", "bogus", "bogus"), "expected error")
+	test.Error(t, validatePermission("messaging", "bogus", "bogus"), "expected error")
+	test.Error(t, validatePermission("messaging", "messaging:channel", "bogus"), "expected error")
+	test.Error(t, validatePermission("messaging", "messaging:channel:", "message.send"), "expected error")
+	test.NoError(t, validatePermission("messaging", "messaging:channel:1", "message.send"), "expected valid response")
+}