Add Scheduler

- Renamed previously called scheduler to forwarder to resolve name
  conflicts

tools/asynq/cmd/cron.go

@@ -0,0 +1,102 @@
+// Copyright 2020 Kentaro Hibino. All rights reserved.
+// Use of this source code is governed by a MIT license
+// that can be found in the LICENSE file.
+
+package cmd
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"sort"
+
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	rootCmd.AddCommand(cronCmd)
+	cronCmd.AddCommand(cronListCmd)
+	cronCmd.AddCommand(cronHistoryCmd)
+}
+
+var cronCmd = &cobra.Command{
+	Use:   "cron",
+	Short: "Manage cron",
+}
+
+var cronListCmd = &cobra.Command{
+	Use:   "ls",
+	Short: "List cron entries",
+	Run:   cronList,
+}
+
+var cronHistoryCmd = &cobra.Command{
+	Use:   "history",
+	Short: "Show history of each cron tasks",
+	Args:  cobra.MinimumNArgs(1),
+	Run:   cronHistory,
+}
+
+func cronList(cmd *cobra.Command, args []string) {
+	r := createRDB()
+
+	entries, err := r.ListSchedulerEntries()
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+	if len(entries) == 0 {
+		fmt.Println("No scheduler entries")
+		return
+	}
+
+	// Sort entries by spec.
+	sort.Slice(entries, func(i, j int) bool {
+		x, y := entries[i], entries[j]
+		return x.Spec < y.Spec
+	})
+
+	cols := []string{"EntryID", "Spec", "Type", "Payload", "Options", "Next", "Prev"}
+	printRows := func(w io.Writer, tmpl string) {
+		for _, e := range entries {
+			fmt.Fprintf(w, tmpl, e.ID, e.Spec, e.Type, e.Payload, e.Opts, e.Next, e.Prev)
+		}
+	}
+	printTable(cols, printRows)
+}
+
+func cronHistory(cmd *cobra.Command, args []string) {
+	r := createRDB()
+	for i, entryID := range args {
+		if i > 0 {
+			fmt.Printf("\n%s\n", separator)
+		}
+		fmt.Println()
+
+		fmt.Printf("Entry: %s\n\n", entryID)
+
+		events, err := r.ListSchedulerEnqueueEvents(entryID)
+		if err != nil {
+			fmt.Printf("error: %v\n", err)
+			continue
+		}
+		if len(events) == 0 {
+			fmt.Printf("No scheduler enqueue events found for entry: %s\n", entryID)
+			continue
+		}
+
+		// Sort entries by enqueuedAt timestamp.
+		sort.Slice(events, func(i, j int) bool {
+			x, y := events[i], events[j]
+			return x.EnqueuedAt.Unix() > y.EnqueuedAt.Unix()
+		})
+
+		cols := []string{"TaskID", "EnqueuedAt"}
+		printRows := func(w io.Writer, tmpl string) {
+			for _, e := range events {
+				fmt.Fprintf(w, tmpl, e.TaskID, e.EnqueuedAt)
+			}
+		}
+		printTable(cols, printRows)
+	}
+}