fixup! Update go.mod and go.sum (#48)

internal/config/validator.go

@@ -2,12 +2,39 @@ package config
 
 import (
 	"fmt"
+	"regexp"
 	"strings"
+	"time"
 )
 
 const (
 	MinPort = 1
 	MaxPort = 65535
+
+	// DNS1123LabelMaxLength is the maximum length of a DNS label (RFC 1123)
+	DNS1123LabelMaxLength = 63
+	// DNS1123SubdomainMaxLength is the maximum length of a DNS subdomain name
+	DNS1123SubdomainMaxLength = 253
+)
+
+var (
+	// dns1123LabelRegexp matches valid DNS labels (RFC 1123)
+	// Must consist of lowercase alphanumeric characters or '-', start with alphanumeric, end with alphanumeric
+	dns1123LabelRegexp = regexp.MustCompile(`^[a-z0-9]([-a-z0-9]*[a-z0-9])?$`)
+
+	// dns1123SubdomainRegexp matches valid DNS subdomain names
+	// A series of DNS labels separated by dots (no consecutive dots allowed)
+	dns1123SubdomainRegexp = regexp.MustCompile(`^[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*$`)
+
+	// contextNameRegexp matches valid context names
+	// Allows alphanumeric characters, hyphens, and underscores (to support various kubeconfig naming conventions)
+	contextNameRegexp = regexp.MustCompile(`^[a-zA-Z0-9]([a-zA-Z0-9_-]*[a-zA-Z0-9])?$`)
+
+	// validResourceTypes contains the allowed Kubernetes resource types
+	validResourceTypes = []string{"pod", "service"}
+
+	// validHealthCheckMethods contains the allowed health check methods
+	validHealthCheckMethods = []string{"tcp-dial", "data-transfer"}
 )
 
 // IsValidPort returns true if the port number is within the valid range (1-65535).
@@ -51,6 +78,7 @@ func (v *Validator) ValidateConfigWithOptions(cfg *Config, allowEmpty bool) []Va
 	// If empty configs are allowed and this config is empty, skip structure validation
 	if allowEmpty && cfg.IsEmpty() {
 		// Still validate health check and reliability if present (they don't require forwards)
+		errs = append(errs, v.validateSpecDurations(cfg)...)
 		return errs
 	}
 
@@ -74,6 +102,9 @@ func (v *Validator) ValidateConfigWithOptions(cfg *Config, allowEmpty bool) []Va
 		errs = append(errs, v.validateMDNS(cfg)...)
 	}
 
+	// Validate duration fields in specs
+	errs = append(errs, v.validateSpecDurations(cfg)...)
+
 	return errs
 }
 
@@ -95,6 +126,11 @@ func (v *Validator) validateStructure(cfg *Config) []ValidationError {
 				Field:   fmt.Sprintf("contexts[%d].name", i),
 				Message: "Context name cannot be empty",
 			})
+		} else {
+			// Validate context name format (alphanumeric, hyphens, underscores)
+			if err := validateContextName(ctx.Name, fmt.Sprintf("contexts[%d].name", i)); err != nil {
+				errs = append(errs, *err)
+			}
 		}
 
 		if len(ctx.Namespaces) == 0 {
@@ -111,6 +147,11 @@ func (v *Validator) validateStructure(cfg *Config) []ValidationError {
 					Field:   fmt.Sprintf("contexts[%d].namespaces[%d].name", i, j),
 					Message: fmt.Sprintf("Namespace name cannot be empty in context '%s'", ctx.Name),
 				})
+			} else {
+				// Validate namespace name follows DNS subdomain conventions (Kubernetes requirement)
+				if err := validateNamespaceName(ns.Name, fmt.Sprintf("contexts[%d].namespaces[%d].name", i, j)); err != nil {
+					errs = append(errs, *err)
+				}
 			}
 
 			if len(ns.Forwards) == 0 {
@@ -139,29 +180,38 @@ func (v *Validator) validateForward(fwd *Forward) []ValidationError {
 		errs = append(errs, v.validateResource(fwd)...)
 	}
 
-	// Validate protocol
-	if fwd.Protocol != "" && fwd.Protocol != "tcp" && fwd.Protocol != "udp" {
+	// Validate protocol - only "tcp" is currently supported
+	if fwd.Protocol != "" && fwd.Protocol != "tcp" {
 		errs = append(errs, ValidationError{
 			Field:   "protocol",
-			Message: fmt.Sprintf("Invalid protocol '%s' for forward %s (must be 'tcp' or 'udp')", fwd.Protocol, fwd.ID()),
+			Message: fmt.Sprintf("Invalid protocol '%s' for forward %s (only 'tcp' is supported)", fwd.Protocol, fwd.ID()),
 		})
 	}
 
 	// Validate ports
-	if fwd.Port < MinPort || fwd.Port > MaxPort {
+	if !IsValidPort(fwd.Port) {
 		errs = append(errs, ValidationError{
 			Field:   "port",
 			Message: fmt.Sprintf("Invalid port %d for forward %s (must be between %d and %d)", fwd.Port, fwd.ID(), MinPort, MaxPort),
 		})
 	}
 
-	if fwd.LocalPort < MinPort || fwd.LocalPort > MaxPort {
+	if !IsValidPort(fwd.LocalPort) {
 		errs = append(errs, ValidationError{
 			Field:   "localPort",
 			Message: fmt.Sprintf("Invalid localPort %d for forward %s (must be between %d and %d)", fwd.LocalPort, fwd.ID(), MinPort, MaxPort),
 		})
 	}
 
+	// Note: Alias validation is handled in validateMDNS since aliases are primarily
+	// used for mDNS hostname registration. We only validate alias format when mDNS
+	// is enabled to avoid unnecessary restrictions on non-mDNS usage.
+
+	// Validate HTTP log configuration if enabled
+	if fwd.HTTPLog != nil && fwd.HTTPLog.Enabled {
+		errs = append(errs, v.validateHTTPLog(fwd)...)
+	}
+
 	return errs
 }
 
@@ -169,18 +219,44 @@ func (v *Validator) validateForward(fwd *Forward) []ValidationError {
 func (v *Validator) validateResource(fwd *Forward) []ValidationError {
 	var errs []ValidationError
 
+	// Validate resource format (must be "type/name" or just "type" for pod with selector)
 	parts := strings.SplitN(fwd.Resource, "/", 2)
 	resourceType := parts[0]
 
-	// Valid resource types: pod, service
-	if resourceType != "pod" && resourceType != "service" {
+	// Validate resource type
+	if !isValidResourceType(resourceType) {
 		errs = append(errs, ValidationError{
 			Field:   "resource",
-			Message: fmt.Sprintf("Invalid resource type '%s' for forward %s (must be 'pod' or 'service')", resourceType, fwd.ID()),
+			Message: fmt.Sprintf("Invalid resource type '%s' for forward %s (must be one of: %s)", resourceType, fwd.ID(), strings.Join(validResourceTypes, ", ")),
 		})
 		return errs
 	}
 
+	// Validate resource name if provided
+	if len(parts) == 2 {
+		resourceName := parts[1]
+		if resourceName == "" {
+			// Use resource-type-specific error message for better clarity
+			entityType := "Resource"
+			switch resourceType {
+			case "pod":
+				entityType = "Pod"
+			case "service":
+				entityType = "Service"
+			}
+			errs = append(errs, ValidationError{
+				Field:   "resource",
+				Message: fmt.Sprintf("%s name cannot be empty for forward %s", entityType, fwd.ID()),
+			})
+		} else {
+			// Validate resource name follows DNS subdomain conventions
+			if err := validateDNS1123Subdomain(resourceName, "resource", "Resource name"); err != nil {
+				err.Message = fmt.Sprintf("%s for forward %s", err.Message, fwd.ID())
+				errs = append(errs, *err)
+			}
+		}
+	}
+
 	// For pod resources
 	if resourceType == "pod" {
 		if len(parts) == 2 {
@@ -191,14 +267,6 @@ func (v *Validator) validateResource(fwd *Forward) []ValidationError {
 					Message: fmt.Sprintf("Forward %s uses explicit pod name (%s) and should not have a selector", fwd.ID(), fwd.Resource),
 				})
 			}
-
-			// Validate pod name is not empty
-			if parts[1] == "" {
-				errs = append(errs, ValidationError{
-					Field:   "resource",
-					Message: fmt.Sprintf("Pod name cannot be empty for forward %s", fwd.ID()),
-				})
-			}
 		} else if fwd.Selector == "" {
 			// pod (no name) - must have selector
 			errs = append(errs, ValidationError{
@@ -213,7 +281,7 @@ func (v *Validator) validateResource(fwd *Forward) []ValidationError {
 		if len(parts) < 2 || parts[1] == "" {
 			errs = append(errs, ValidationError{
 				Field:   "resource",
-				Message: fmt.Sprintf("Service name cannot be empty for forward %s", fwd.ID()),
+				Message: fmt.Sprintf("Service name cannot be empty for forward %s (format: service/name)", fwd.ID()),
 			})
 		}
 
@@ -259,6 +327,109 @@ func (v *Validator) validateDuplicatePorts(cfg *Config) []ValidationError {
 	return errs
 }
 
+// validateSpecDurations validates duration strings in HealthCheck and Reliability specs.
+func (v *Validator) validateSpecDurations(cfg *Config) []ValidationError {
+	var errs []ValidationError
+
+	// Validate HealthCheck durations
+	if cfg.HealthCheck != nil {
+		if cfg.HealthCheck.Interval != "" {
+			if _, err := time.ParseDuration(cfg.HealthCheck.Interval); err != nil {
+				errs = append(errs, ValidationError{
+					Field:   "healthCheck.interval",
+					Message: fmt.Sprintf("Invalid health check interval '%s': %v", cfg.HealthCheck.Interval, err),
+				})
+			}
+		}
+
+		if cfg.HealthCheck.Timeout != "" {
+			if _, err := time.ParseDuration(cfg.HealthCheck.Timeout); err != nil {
+				errs = append(errs, ValidationError{
+					Field:   "healthCheck.timeout",
+					Message: fmt.Sprintf("Invalid health check timeout '%s': %v", cfg.HealthCheck.Timeout, err),
+				})
+			}
+		}
+
+		if cfg.HealthCheck.MaxConnectionAge != "" {
+			if _, err := time.ParseDuration(cfg.HealthCheck.MaxConnectionAge); err != nil {
+				errs = append(errs, ValidationError{
+					Field:   "healthCheck.maxConnectionAge",
+					Message: fmt.Sprintf("Invalid max connection age '%s': %v", cfg.HealthCheck.MaxConnectionAge, err),
+				})
+			}
+		}
+
+		if cfg.HealthCheck.MaxIdleTime != "" {
+			if _, err := time.ParseDuration(cfg.HealthCheck.MaxIdleTime); err != nil {
+				errs = append(errs, ValidationError{
+					Field:   "healthCheck.maxIdleTime",
+					Message: fmt.Sprintf("Invalid max idle time '%s': %v", cfg.HealthCheck.MaxIdleTime, err),
+				})
+			}
+		}
+
+		// Validate health check method
+		if cfg.HealthCheck.Method != "" && !isValidHealthCheckMethod(cfg.HealthCheck.Method) {
+			errs = append(errs, ValidationError{
+				Field:   "healthCheck.method",
+				Message: fmt.Sprintf("Invalid health check method '%s' (must be one of: %s)", cfg.HealthCheck.Method, strings.Join(validHealthCheckMethods, ", ")),
+			})
+		}
+	}
+
+	// Validate Reliability durations
+	if cfg.Reliability != nil {
+		if cfg.Reliability.TCPKeepalive != "" {
+			if _, err := time.ParseDuration(cfg.Reliability.TCPKeepalive); err != nil {
+				errs = append(errs, ValidationError{
+					Field:   "reliability.tcpKeepalive",
+					Message: fmt.Sprintf("Invalid TCP keepalive duration '%s': %v", cfg.Reliability.TCPKeepalive, err),
+				})
+			}
+		}
+
+		if cfg.Reliability.DialTimeout != "" {
+			if _, err := time.ParseDuration(cfg.Reliability.DialTimeout); err != nil {
+				errs = append(errs, ValidationError{
+					Field:   "reliability.dialTimeout",
+					Message: fmt.Sprintf("Invalid dial timeout '%s': %v", cfg.Reliability.DialTimeout, err),
+				})
+			}
+		}
+
+		if cfg.Reliability.WatchdogPeriod != "" {
+			if _, err := time.ParseDuration(cfg.Reliability.WatchdogPeriod); err != nil {
+				errs = append(errs, ValidationError{
+					Field:   "reliability.watchdogPeriod",
+					Message: fmt.Sprintf("Invalid watchdog period '%s': %v", cfg.Reliability.WatchdogPeriod, err),
+				})
+			}
+		}
+	}
+
+	return errs
+}
+
+// validateHTTPLog validates HTTP log configuration.
+func (v *Validator) validateHTTPLog(fwd *Forward) []ValidationError {
+	var errs []ValidationError
+
+	if fwd.HTTPLog == nil {
+		return errs
+	}
+
+	// Validate maxBodySize is non-negative
+	if fwd.HTTPLog.MaxBodySize < 0 {
+		errs = append(errs, ValidationError{
+			Field:   "httpLog.maxBodySize",
+			Message: fmt.Sprintf("Invalid maxBodySize %d for forward %s (must be non-negative)", fwd.HTTPLog.MaxBodySize, fwd.ID()),
+		})
+	}
+
+	return errs
+}
+
 // FormatValidationErrors formats validation errors into a human-readable string.
 func FormatValidationErrors(errs []ValidationError) string {
 	if len(errs) == 0 {
@@ -334,7 +505,7 @@ func (v *Validator) validateMDNS(cfg *Config) []ValidationError {
 // Hostnames must start with alphanumeric, contain only alphanumeric and hyphens,
 // and be 1-63 characters long.
 func isValidHostname(name string) bool {
-	if len(name) == 0 || len(name) > 63 {
+	if len(name) == 0 || len(name) > DNS1123LabelMaxLength {
 		return false
 	}
 
@@ -363,3 +534,149 @@ func isValidHostname(name string) bool {
 func isAlphanumeric(c byte) bool {
 	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9')
 }
+
+// isValidResourceType returns true if the resource type is valid.
+func isValidResourceType(resourceType string) bool {
+	for _, rt := range validResourceTypes {
+		if rt == resourceType {
+			return true
+		}
+	}
+	return false
+}
+
+// isValidHealthCheckMethod returns true if the health check method is valid.
+func isValidHealthCheckMethod(method string) bool {
+	for _, m := range validHealthCheckMethods {
+		if m == method {
+			return true
+		}
+	}
+	return false
+}
+
+// validateContextName validates that a context name follows the allowed format.
+// Context names must consist of alphanumeric characters, hyphens, or underscores,
+// and must start and end with an alphanumeric character.
+// This more permissive validation supports various kubeconfig naming conventions
+// (e.g., "gke_project_zone_cluster", "minikube", "docker-desktop").
+func validateContextName(name, field string) *ValidationError {
+	if len(name) > DNS1123SubdomainMaxLength {
+		return &ValidationError{
+			Field:   field,
+			Message: fmt.Sprintf("Context name '%s' exceeds maximum length of %d characters", name, DNS1123SubdomainMaxLength),
+		}
+	}
+
+	if !contextNameRegexp.MatchString(name) {
+		return &ValidationError{
+			Field:   field,
+			Message: fmt.Sprintf("Context name '%s' is not valid (must consist of alphanumeric characters, hyphens, or underscores, and start/end with alphanumeric)", name),
+		}
+	}
+
+	return nil
+}
+
+// validateNamespaceName validates that a namespace name is a valid DNS subdomain (RFC 1123).
+// Kubernetes namespaces must follow DNS subdomain format which allows dots for subdomain separation.
+// This is more permissive than DNS labels and supports names like "kube-system", "my-app.ns".
+func validateNamespaceName(name, field string) *ValidationError {
+	if len(name) > DNS1123SubdomainMaxLength {
+		return &ValidationError{
+			Field:   field,
+			Message: fmt.Sprintf("Namespace name '%s' exceeds maximum length of %d characters", name, DNS1123SubdomainMaxLength),
+		}
+	}
+
+	if !dns1123SubdomainRegexp.MatchString(name) {
+		return &ValidationError{
+			Field:   field,
+			Message: fmt.Sprintf("Namespace name '%s' is not a valid DNS subdomain (must consist of lowercase alphanumeric characters, '-', or '.', start with alphanumeric, end with alphanumeric)", name),
+		}
+	}
+
+	return nil
+}
+
+// validateDNS1123Label validates that a name is a valid DNS label (RFC 1123).
+// Used for context names and namespace names.
+func validateDNS1123Label(name, field, entityType string) *ValidationError {
+	if len(name) > DNS1123LabelMaxLength {
+		return &ValidationError{
+			Field:   field,
+			Message: fmt.Sprintf("%s name '%s' exceeds maximum length of %d characters", entityType, name, DNS1123LabelMaxLength),
+		}
+	}
+
+	if !dns1123LabelRegexp.MatchString(name) {
+		return &ValidationError{
+			Field:   field,
+			Message: fmt.Sprintf("%s name '%s' is not a valid DNS label (must consist of lowercase alphanumeric characters or '-', start with alphanumeric, end with alphanumeric)", entityType, name),
+		}
+	}
+
+	return nil
+}
+
+// validateDNS1123Subdomain validates that a name is a valid DNS subdomain name (RFC 1123).
+// Used for resource names which can contain dots.
+func validateDNS1123Subdomain(name, field, entityType string) *ValidationError {
+	if len(name) > DNS1123SubdomainMaxLength {
+		return &ValidationError{
+			Field:   field,
+			Message: fmt.Sprintf("%s '%s' exceeds maximum length of %d characters", entityType, name, DNS1123SubdomainMaxLength),
+		}
+	}
+
+	if !dns1123SubdomainRegexp.MatchString(name) {
+		return &ValidationError{
+			Field:   field,
+			Message: fmt.Sprintf("%s '%s' is not a valid DNS subdomain name (must consist of lowercase alphanumeric characters, '-', or '.', start with alphanumeric, end with alphanumeric)", entityType, name),
+		}
+	}
+
+	return nil
+}
+
+// ValidatePort validates a port number and returns an error if invalid.
+// This is a public function that can be used externally.
+func ValidatePort(port int, name string) error {
+	if !IsValidPort(port) {
+		return fmt.Errorf("%s must be between %d and %d, got %d", name, MinPort, MaxPort, port)
+	}
+	return nil
+}
+
+// ValidateResourceFormat validates that a resource string is in the correct format.
+// This is a public function that can be used externally.
+func ValidateResourceFormat(resource string) error {
+	parts := strings.SplitN(resource, "/", 2)
+	if len(parts) != 2 {
+		return fmt.Errorf("resource must be in format 'type/name', got: %s", resource)
+	}
+
+	resourceType := parts[0]
+	if !isValidResourceType(resourceType) {
+		return fmt.Errorf("invalid resource type '%s' (must be one of: %s)", resourceType, strings.Join(validResourceTypes, ", "))
+	}
+
+	if parts[1] == "" {
+		return fmt.Errorf("resource name cannot be empty in '%s'", resource)
+	}
+
+	return nil
+}
+
+// ValidateDuration validates that a string is a valid duration.
+// This is a public function that can be used externally.
+func ValidateDuration(duration, name string) error {
+	if duration == "" {
+		return nil // Empty durations are allowed (will use defaults)
+	}
+	_, err := time.ParseDuration(duration)
+	if err != nil {
+		return fmt.Errorf("invalid %s '%s': %v", name, duration, err)
+	}
+	return nil
+}