[shell] fs log purge (#5344)

* fix: install cronie

* chore: shell delete old logs

* Revert "fix: install cronie"

This reverts commit 920832b04b.

* fix: dayAgo

* fix: Nit: dayAgo => daysAgo

weed/shell/command_fs_log.go

@@ -0,0 +1,53 @@
+package shell
+
+import (
+	"flag"
+	"fmt"
+	"github.com/seaweedfs/seaweedfs/weed/filer"
+	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
+	"io"
+	"time"
+)
+
+func init() {
+	Commands = append(Commands, &commandFsLogPurge{})
+}
+
+type commandFsLogPurge struct {
+}
+
+func (c *commandFsLogPurge) Name() string {
+	return "fs.log.purge"
+}
+
+func (c *commandFsLogPurge) Help() string {
+	return `purge filer logs
+
+	fs.log.purge [-v] [-modifyDayAgo 365]
+`
+}
+
+func (c *commandFsLogPurge) Do(args []string, commandEnv *CommandEnv, writer io.Writer) (err error) {
+	fsLogPurgeCommand := flag.NewFlagSet(c.Name(), flag.ContinueOnError)
+	daysAgo := fsLogPurgeCommand.Uint("daysAgo", 365, "purge logs older than N days")
+	verbose := fsLogPurgeCommand.Bool("v", false, "verbose mode")
+
+	if err = fsLogPurgeCommand.Parse(args); err != nil {
+		return err
+	}
+
+	modificationTimeAgo := time.Now().Add(-time.Hour * 24 * time.Duration(*daysAgo)).Unix()
+	err = filer_pb.ReadDirAllEntries(commandEnv, filer.SystemLogDir, "", func(entry *filer_pb.Entry, isLast bool) error {
+		if entry.Attributes.Mtime > modificationTimeAgo {
+			return nil
+		}
+		if errDel := filer_pb.Remove(commandEnv, filer.SystemLogDir, entry.Name, true, true, true, false, nil); errDel != nil {
+			return errDel
+		}
+		if *verbose {
+			fmt.Fprintf(writer, "delete %s\n", entry.Name)
+		}
+		return nil
+	})
+	return err
+}