fix ci

go.mod

@@ -26,6 +26,7 @@ require (
 	github.com/pingcap/tidb v1.1.0-beta.0.20191213040028-9009da737834
 	github.com/pingcap/tipb v0.0.0-20191209145133-44f75c9bef33
 	github.com/prometheus/client_golang v1.0.0
+	github.com/prometheus/common v0.4.1
 	github.com/sirupsen/logrus v1.4.2
 	github.com/spf13/cobra v0.0.5
 	github.com/spf13/pflag v1.0.3

go.sum

@@ -24,7 +24,9 @@ github.com/StackExchange/wmi v0.0.0-20190523213315-cbe66965904d h1:G0m3OIz70MZUW
 github.com/StackExchange/wmi v0.0.0-20190523213315-cbe66965904d/go.mod h1:3eOhrUMpNV+6aFIbp5/iudMxNCF27Vw2OZgy4xEx0Fg=
 github.com/VividCortex/ewma v1.1.1 h1:MnEK4VOv6n0RSY4vtRe3h11qjxL3+t0B8yOL8iMXdcM=
 github.com/VividCortex/ewma v1.1.1/go.mod h1:2Tkkvm3sRDVXaiyucHiACn4cqf7DpdyLvmxzcbUokwA=
+github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc h1:cAKDfWh5VpdgMhJosfJnn5/FoN2SRZ4p7fJNX58YPaU=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
+github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf h1:qet1QNfXsQxTZqLG4oE62mJzwPIB8+Tee4RNCL9ulrY=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
 github.com/aws/aws-sdk-go v1.26.1 h1:JGQggXhOiNJIqsmbYUl3cYtJZUffeOWlHtxfzGK7WPI=
@@ -567,6 +569,7 @@ google.golang.org/grpc v1.25.1 h1:wdKvqQk7IttEw92GoRyKG2IDrUIpgpj6H6m81yfeMW0=
 google.golang.org/grpc v1.25.1/go.mod h1:c3i+UQWmh7LiEpx4sFZnkU36qjEYZ0imhYfXVyQciAY=
 gopkg.in/airbrake/gobrake.v2 v2.0.9/go.mod h1:/h5ZAUhDkGaJfjzjKLSjv6zCL6O0LLBxU4K+aSYdM/U=
 gopkg.in/alecthomas/gometalinter.v2 v2.0.12/go.mod h1:NDRytsqEZyolNuAgTzJkZMkSQM7FIKyzVzGhjB/qfYo=
+gopkg.in/alecthomas/kingpin.v2 v2.2.6 h1:jMFz6MfLP0/4fUyZle81rXUoxOBFi19VUFKVDOQfozc=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/alecthomas/kingpin.v3-unstable v3.0.0-20180810215634-df19058c872c/go.mod h1:3HH7i1SgMqlzxCcBmUHW657sD4Kvv9sC3HpL3YukzwA=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

pkg/backup/client.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"encoding/hex"
 	"encoding/json"
-	"fmt"
 	"io"
 	"sync"
 	"time"
@@ -123,14 +122,26 @@ func (bc *Client) SetStorage(ctx context.Context, backend *backup.StorageBackend
 
 // SaveBackupTS saves the backup ts at the given path.
 func (bc *Client) SaveBackupTS(ctx context.Context, backupTS uint64) error {
+	if exists, _ := bc.storage.FileExists(ctx, utils.TSFile); exists {
+		return errors.New("this storage has backup file, consider clear this storage or change to new one")
+	}
 	backendURL := storage.FormatBackendURL(bc.backend)
+
 	log.Info("save backup ts", zap.Stringer("path", &backendURL))
-	fileString := fmt.Sprintf(
-		"**************************************"+
-			"\nStarted backup at: %v\nBackupTS: %d\n"+
-			"**************************************",
-		time.Now().Format("2006-01-02 15:04:05"), backupTS)
-	return bc.storage.Write(ctx, utils.TSFile, []byte(fileString))
+	type fileContent struct {
+		StartedAt string `json:"started_at"`
+		BackupTS  uint64 `json:"backup_ts"`
+	}
+	f := &fileContent{
+		StartedAt: time.Now().Format("2006-01-02 15:04:05"),
+		BackupTS:  backupTS,
+	}
+	fileBytes, err := json.MarshalIndent(f, "", "\t")
+	if err != nil {
+		return err
+	}
+
+	return bc.storage.Write(ctx, utils.TSFile, fileBytes)
 }
 
 // GetBackupTS get the backup ts from given path.