Added property to force http server to bind only to IPv4 address

cmd/packer-sdc/internal/renderdocs/docs-partials/packer-plugin-sdk/multistep/commonsteps/HTTPConfig-not-required.mdx

@@ -34,4 +34,6 @@
 - `http_bind_address` (string) - This is the bind address for the HTTP server. Defaults to 0.0.0.0 so that
   it will work with any network interface.
 
+- `http_only_ipv4` (bool) - If true the HTTP server will only be bound to an IPv4 interface
+
 <!-- End of code generated from the comments of the HTTPConfig struct in multistep/commonsteps/http_config.go; -->

multistep/commonsteps/http_config.go

@@ -58,6 +58,8 @@ type HTTPConfig struct {
 	// interface with a non-loopback address. Either `http_bind_address` or
 	// `http_interface` can be specified.
 	HTTPInterface string `mapstructure:"http_interface" undocumented:"true"`
+	// If true the HTTP server will only be bound to an IPv4 interface
+	HTTPOnlyIPv4 bool `mapstructure:"http_only_ipv4"`
 }
 
 func (c *HTTPConfig) Prepare(ctx *interpolate.Context) []error {

multistep/commonsteps/step_http_server.go

@@ -20,11 +20,12 @@ import (
 
 func HTTPServerFromHTTPConfig(cfg *HTTPConfig) *StepHTTPServer {
 	return &StepHTTPServer{
-		HTTPDir:     cfg.HTTPDir,
-		HTTPContent: cfg.HTTPContent,
-		HTTPPortMin: cfg.HTTPPortMin,
-		HTTPPortMax: cfg.HTTPPortMax,
-		HTTPAddress: cfg.HTTPAddress,
+		HTTPDir:      cfg.HTTPDir,
+		HTTPContent:  cfg.HTTPContent,
+		HTTPPortMin:  cfg.HTTPPortMin,
+		HTTPPortMax:  cfg.HTTPPortMax,
+		HTTPAddress:  cfg.HTTPAddress,
+		HTTPOnlyIPv4: cfg.HTTPOnlyIPv4,
 	}
 }
 
@@ -40,11 +41,12 @@ func HTTPServerFromHTTPConfig(cfg *HTTPConfig) *StepHTTPServer {
 //
 //	http_port int - The port the HTTP server started on.
 type StepHTTPServer struct {
-	HTTPDir     string
-	HTTPContent map[string]string
-	HTTPPortMin int
-	HTTPPortMax int
-	HTTPAddress string
+	HTTPDir      string
+	HTTPContent  map[string]string
+	HTTPPortMin  int
+	HTTPPortMax  int
+	HTTPAddress  string
+	HTTPOnlyIPv4 bool
 
 	l *net.Listener
 }
@@ -102,11 +104,15 @@ func (s *StepHTTPServer) Run(ctx context.Context, state multistep.StateBag) mult
 
 	// Find an available TCP port for our HTTP server
 	var err error
+	network := "tcp"
+	if s.HTTPOnlyIPv4 {
+		network = "tcp4"
+	}
 	s.l, err = net.ListenRangeConfig{
 		Min:     s.HTTPPortMin,
 		Max:     s.HTTPPortMax,
 		Addr:    s.HTTPAddress,
-		Network: "tcp",
+		Network: network,
 	}.Listen(ctx)
 
 	if err != nil {