rebuild: Add explicit flag for updating

cmd/rebuild.go

@@ -18,6 +18,7 @@ var Rebuild wisski_distillery.Command = rebuild{}
 type rebuild struct {
 	Parallel int `short:"a" long:"parallel" description:"run on (at most) this many instances in parallel. 0 for no limit." default:"1"`
 
+	System                bool   `short:"s" long:"system-update" description:"Update the system configuration according to other flags"`
 	PHPVersion            string `short:"p" long:"php" description:"update to specific php version to use for instance. Should be one of '8.0', '8.1'."`
 	OPCacheDevelopment    bool   `short:"o" long:"opcache-devel" description:"Include opcache development configuration"`
 	ContentSecurityPolicy string `short:"c" long:"content-security-policy" description:"Setup ContentSecurityPolicy"`
@@ -27,6 +28,21 @@ type rebuild struct {
 	} `positional-args:"true"`
 }
 
+var errRebuildNoSystem = exit.Error{
+	Message:  "flags for system reconfiguration have been set, but `--system' was not provided",
+	ExitCode: exit.ExitCommandArguments,
+}
+
+func (rb rebuild) AfterParse() error {
+	if rb.System {
+		return nil
+	}
+	if rb.PHPVersion != "" || rb.OPCacheDevelopment || rb.ContentSecurityPolicy != "" {
+		return errRebuildNoSystem
+	}
+	return nil
+}
+
 func (rebuild) Description() wisski_distillery.Description {
 	return wisski_distillery.Description{
 		Requirements: cli.Requirements{
@@ -55,11 +71,16 @@ func (rb rebuild) Run(context wisski_distillery.Context) (err error) {
 
 	// and do the actual rebuild
 	return status.WriterGroup(context.Stderr, rb.Parallel, func(instance *wisski.WissKI, writer io.Writer) error {
-		return instance.SystemManager().Apply(context.Context, writer, models.System{
+		sys := instance.System
+		if rb.System {
+			sys = models.System{
 				PHP:                   rb.PHPVersion,
 				OpCacheDevelopment:    rb.OPCacheDevelopment,
 				ContentSecurityPolicy: rb.ContentSecurityPolicy,
-		}, true)
+			}
+		}
+
+		return instance.SystemManager().Apply(context.Context, writer, sys, true)
 	}, wissKIs, status.SmartMessage(func(item *wisski.WissKI) string {
 		return fmt.Sprintf("rebuild %q", item.Slug)
 	}))