preserver BC for people using 'command' option

common/shell-local/run.go

@@ -15,8 +15,9 @@ import (
 )
 
 type ExecuteCommandTemplate struct {
-	Vars   string
-	Script string
+	Vars    string
+	Script  string
+	Command string
 }
 
 func Run(ui packer.Ui, config *Config) (bool, error) {
@@ -106,8 +107,9 @@ func createInlineScriptFile(config *Config) (string, error) {
 // the host OS
 func createInterpolatedCommands(config *Config, script string, flattenedEnvVars string) ([]string, error) {
 	config.Ctx.Data = &ExecuteCommandTemplate{
-		Vars:   flattenedEnvVars,
-		Script: script,
+		Vars:    flattenedEnvVars,
+		Script:  script,
+		Command: script,
 	}
 
 	interpolatedCmds := make([]string, len(config.ExecuteCommand))

website/source/docs/provisioners/shell-local.html.md

@@ -78,18 +78,21 @@ Optional parameters:
     This is treated as a [template engine](/docs/templates/engine.html).
     There are two available variables: `Script`, which is the path to the script
     to run, and `Vars`, which is the list of `environment_vars`, if configured
+
     If you choose to set this option, make sure that the first element in the
-    array is the shell program you want to use (for example, "sh" or
-    "/usr/local/bin/zsh" or even "powershell.exe" although anything other than
-    a flavor of the shell command language is not explicitly supported and may
-    be broken by assumptions made within Packer), and a later element in the
-    array must be `{{.Script}}`.
-
-    For backwards compatability, {{.Command}} is also available to use in
-    `execute_command` but it is decoded the same way as {{.Script}}. We
-    recommend using {{.Script}} for the sake of clarity, as even when you set
-    only a single `command` to run, Packer writes it to a temporary file and
-    then runs it as a script.
+    array is the shell program you want to use (for example, "sh"), and a later
+    element in the array must be `{{.Script}}`.
+
+    This option provides you a great deal of flexibility. You may choose to
+    provide your own shell program, for example "/usr/local/bin/zsh" or even
+    "powershell.exe". However, with great power comes great responsibility -
+    these commands are not officially supported and things like environment
+    variables may not work if you use a different shell than the default.
+
+    For backwards compatability, you may also use {{.Command}}, but it is
+    decoded the same way as {{.Script}}. We recommend using {{.Script}} for the
+    sake of clarity, as even when you set only a single `command` to run,
+    Packer writes it to a temporary file and then runs it as a script.
 
 -   `inline_shebang` (string) - The
     [shebang](http://en.wikipedia.org/wiki/Shebang_%28Unix%29) value to use when