Disallows setting build.platform

.web-docs/components/builder/docker/README.md

@@ -297,8 +297,6 @@ You must specify (only) one of `commit`, `discard`, or `export_path`.
   containers, because our normal docker bindings do not work for them.
 
 - `platform` (string) - Set platform if server is multi-platform capable
-
-  This cannot be used at the same time as `build`; instead, use `build.platform`
 
 - `login` (bool) - This is used to login to a private docker repository (e.g., dockerhub)
   to build or pull a private base container. For pushing to a private
@@ -396,8 +394,6 @@ source "docker" "example" {
 - `arguments` (map[string]string) - A mapping of additional build args to provide. The key of
   the object is the argument name, the value is the argument value.
 
-- `platform` (string) - Set platform if server is multi-platform capable
-
 - `pull` (boolean) - Pull the image when building the base docker image.
 
   Note: defaults to true, to disable this, explicitly set it to false.

builder/docker/config.go

@@ -140,8 +140,6 @@ type Config struct {
 	// containers, because our normal docker bindings do not work for them.
 	WindowsContainer bool `mapstructure:"windows_container" required:"false"`
 	// Set platform if server is multi-platform capable
-	//
-	// This cannot be used at the same time as `build`; instead, use `build.platform`
 	Platform string `mapstructure:"platform" required:"false"`
 
 	// This is used to login to a private docker repository (e.g., dockerhub)
@@ -224,9 +222,9 @@ func (c *Config) Prepare(raws ...interface{}) ([]string, error) {
 		}
 
 		if c.Platform != "" {
-			errs = packersdk.MultiErrorAppend(errs, errors.New("when running a bootstrap build, the `platform` option cannot be specified (use `build.platform` instead)"))
+			c.BuildConfig.Platform = c.Platform
 		}
-		c.Platform = c.BuildConfig.Platform
+
 	} else {
 		// Default Pull if it wasn't set
 		hasPull := false

builder/docker/dockerfile_config.go

@@ -36,8 +36,7 @@ type DockerfileBootstrapConfig struct {
 	// the object is the argument name, the value is the argument value.
 	Arguments map[string]string `mapstructure:"arguments" required:"false"`
 
-	// Set platform if server is multi-platform capable
-	Platform string `mapstructure:"platform" required:"false"`
+	Platform string `mapstructure-to-hcl2:",skip"`
 
 	// Pull the image when building the base docker image.
 	//

docs-partials/builder/docker/Config-not-required.mdx

@@ -99,8 +99,6 @@
   containers, because our normal docker bindings do not work for them.
 
 - `platform` (string) - Set platform if server is multi-platform capable
-
-  This cannot be used at the same time as `build`; instead, use `build.platform`
 
 - `login` (bool) - This is used to login to a private docker repository (e.g., dockerhub)
   to build or pull a private base container. For pushing to a private

docs-partials/builder/docker/DockerfileBootstrapConfig-not-required.mdx

@@ -7,8 +7,6 @@
 - `arguments` (map[string]string) - A mapping of additional build args to provide. The key of
   the object is the argument name, the value is the argument value.
 
-- `platform` (string) - Set platform if server is multi-platform capable
-
 - `pull` (boolean) - Pull the image when building the base docker image.
 
   Note: defaults to true, to disable this, explicitly set it to false.