Simplify CLI by requiring explicit job names.

Job names are derived from job type + user-defined name in config file
CLI now has subcommands corresponding 1:1 to the config file sections:

        push,pull,autosnap,prune

A subcommand always expects a job name, thus executes exactly one job.

Dict-style syntax also used for PullACL and Sink sections.

jobrun package is currently only used for autosnap, all others need to
be invoked repeatedly via external tool.
Plan is to re-integrate jobrun in an explicit daemon-mode (subcommand).

cmd/stdinserver.go

@@ -11,18 +11,13 @@ import (
 	"os"
 )
 
-var stdinserver struct {
-	identity string
-}
-
 var StdinserverCmd = &cobra.Command{
-	Use:   "stdinserver",
+	Use:   "stdinserver CLIENT_IDENTITY",
 	Short: "start in stdin server mode (from authorized_keys file)",
 	Run:   cmdStdinServer,
 }
 
 func init() {
-	StdinserverCmd.Flags().StringVar(&stdinserver.identity, "identity", "", "")
 	RootCmd.AddCommand(StdinserverCmd)
 }
 
@@ -36,37 +31,36 @@ func cmdStdinServer(cmd *cobra.Command, args []string) {
 		}
 	}()
 
-	if stdinserver.identity == "" {
-		err = fmt.Errorf("identity flag not set")
+	if len(args) != 1 || args[0] == "" {
+		err = fmt.Errorf("must specify client identity as positional argument")
+		return
+	}
+	identity := args[0]
+
+	pullACL := conf.PullACLs[identity]
+	if pullACL == nil {
+		err = fmt.Errorf("could not find PullACL for identity '%s'", identity)
 		return
 	}
-	identity := stdinserver.identity
 
 	var sshByteStream io.ReadWriteCloser
 	if sshByteStream, err = sshbytestream.Incoming(); err != nil {
 		return
 	}
 
-	findMapping := func(cm []ClientMapping, identity string) zfs.DatasetMapping {
-		for i := range cm {
-			if cm[i].From == identity {
-				return cm[i].Mapping
-			}
-		}
-		return nil
-	}
-	sinkMapping := func(identity string) (sink zfs.DatasetMapping, err error) {
-		if sink = findMapping(conf.Sinks, identity); sink == nil {
+	sinkMapping := func(identity string) (m zfs.DatasetMapping, err error) {
+		sink := conf.Sinks[identity]
+		if sink == nil {
 			return nil, fmt.Errorf("could not find sink for dataset")
 		}
-		return
+		return sink.Mapping, nil
 	}
 
 	sinkLogger := golog.New(logOut, fmt.Sprintf("sink[%s] ", identity), logFlags)
 	handler := Handler{
 		Logger:          sinkLogger,
 		SinkMappingFunc: sinkMapping,
-		PullACL:         findMapping(conf.PullACLs, identity),
+		PullACL:         pullACL.Mapping,
 	}
 
 	if err = rpc.ListenByteStreamRPC(sshByteStream, identity, handler, sinkLogger); err != nil {