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/autosnap.go

@@ -5,14 +5,11 @@ import (
 	"github.com/spf13/cobra"
 	"github.com/zrepl/zrepl/jobrun"
 	"github.com/zrepl/zrepl/zfs"
+	"os"
 	"sync"
 	"time"
 )
 
-var autosnapArgs struct {
-	job string
-}
-
 var AutosnapCmd = &cobra.Command{
 	Use:   "autosnap",
 	Short: "perform automatic snapshotting",
@@ -20,7 +17,6 @@ var AutosnapCmd = &cobra.Command{
 }
 
 func init() {
-	AutosnapCmd.Flags().StringVar(&autosnapArgs.job, "job", "", "job to run")
 	RootCmd.AddCommand(AutosnapCmd)
 }
 
@@ -33,34 +29,34 @@ func cmdAutosnap(cmd *cobra.Command, args []string) {
 		runner.Start()
 	}()
 
-	log.Printf("autosnap...")
-
-	for i := range conf.Autosnaps {
-
-		snap := conf.Autosnaps[i]
-
-		if autosnapArgs.job == "" || autosnapArgs.job == snap.Name {
-
-			job := jobrun.Job{
-				Name:           fmt.Sprintf("autosnap.%s", snap.Name),
-				RepeatStrategy: snap.Interval,
-				RunFunc: func(log jobrun.Logger) error {
-					log.Printf("doing autosnap: %v", snap)
-					ctx := AutosnapContext{snap}
-					return doAutosnap(ctx, log)
-				},
-			}
-			runner.AddJob(job)
-
-		}
+	if len(args) < 1 {
+		log.Printf("must specify exactly one job as positional argument")
+		os.Exit(1)
 	}
 
+	snap, ok := conf.Autosnaps[args[0]]
+	if !ok {
+		log.Printf("could not find autosnap job: %s", args[0])
+		os.Exit(1)
+	}
+
+	job := jobrun.Job{
+		Name:           snap.JobName,
+		RepeatStrategy: snap.Interval,
+		RunFunc: func(log jobrun.Logger) error {
+			log.Printf("doing autosnap: %v", snap)
+			ctx := AutosnapContext{snap}
+			return doAutosnap(ctx, log)
+		},
+	}
+	runner.AddJob(job)
+
 	wg.Wait()
 
 }
 
 type AutosnapContext struct {
-	Autosnap Autosnap
+	Autosnap *Autosnap
 }
 
 func doAutosnap(ctx AutosnapContext, log Logger) (err error) {