main: Hide several commands from our help

These are commands that either no longer do anything aside from emitting
an error message or are just backward-compatibility aliases for other
commands.

This generalizes our previous situation where we were specifically
hiding "internal-plugin", and does so in a way that fixes the
long-standing cosmetic bug that the column width in the help output was
chosen based on the hidden command "internal-plugin", which is
unfortunately also the longest command in our command set.

commands.go

@@ -26,6 +26,7 @@ const runningInAutomationEnvName = "TF_IN_AUTOMATION"
 // Commands is the mapping of all the available Terraform commands.
 var Commands map[string]cli.CommandFactory
 var PlumbingCommands map[string]struct{}
+var HiddenCommands map[string]struct{}
 
 // Ui is the cli.Ui used for communicating to the outside world.
 var Ui cli.Ui
@@ -96,9 +97,14 @@ func initCommands(
 	PlumbingCommands = map[string]struct{}{
 		"state":        struct{}{}, // includes all subcommands
 		"force-unlock": struct{}{},
-		"push":         struct{}{},
-		"0.12upgrade":  struct{}{},
-		"0.13upgrade":  struct{}{},
+	}
+
+	HiddenCommands = map[string]struct{}{
+		"0.12upgrade":     struct{}{},
+		"0.13upgrade":     struct{}{},
+		"env":             struct{}{},
+		"internal-plugin": struct{}{},
+		"push":            struct{}{},
 	}
 
 	Commands = map[string]cli.CommandFactory{

help.go

@@ -17,6 +17,12 @@ func helpFunc(commands map[string]cli.CommandFactory) string {
 	plumbing := make(map[string]cli.CommandFactory)
 	maxKeyLen := 0
 	for key, f := range commands {
+		if _, ok := HiddenCommands[key]; ok {
+			// We don't consider hidden commands when deciding the
+			// maximum command length.
+			continue
+		}
+
 		if len(key) > maxKeyLen {
 			maxKeyLen = len(key)
 		}
@@ -65,11 +71,6 @@ func listCommands(commands map[string]cli.CommandFactory, maxKeyLen int) string
 	// key length so they can be aligned properly.
 	keys := make([]string, 0, len(commands))
 	for key, _ := range commands {
-		// This is an internal command that users should never call directly so
-		// we will hide it from the command listing.
-		if key == "internal-plugin" {
-			continue
-		}
 		keys = append(keys, key)
 	}
 	sort.Strings(keys)