app/vmbackup: added ability to create and delete snapshots during backup (#428)

* app/vmbackup: added ability to create and delete snapshots during backup

Resolves: https://github.com/VictoriaMetrics/VictoriaMetrics/issues/422

* Add snapshot create and delete url flags

* Fixed errcheck warnings in build

app/vmbackup/main.go

@@ -4,7 +4,9 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"strings"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmbackup/snapshot"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/backup/actions"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/backup/common"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/backup/fslocal"
@@ -14,9 +16,13 @@ import (
 )
 
 var (
-	storageDataPath = flag.String("storageDataPath", "victoria-metrics-data", "Path to VictoriaMetrics data. Must match -storageDataPath from VictoriaMetrics or vmstorage")
+	storageDataPath   = flag.String("storageDataPath", "victoria-metrics-data", "Path to VictoriaMetrics data. Must match -storageDataPath from VictoriaMetrics or vmstorage")
-	snapshotName    = flag.String("snapshotName", "", "Name for the snapshot to backup. See https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#how-to-work-with-snapshots")
+	snapshotName      = flag.String("snapshotName", "", "Name for the snapshot to backup. See https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/README.md#how-to-work-with-snapshots")
-	dst             = flag.String("dst", "", "Where to put the backup on the remote storage. "+
+	snapshotCreateURL = flag.String("snapshot.createURL", "", "VictoriaMetrics create snapshot url. When this is given a snapshot will automatically be created during backup."+
+		"Example: http://victoriametrics:8428/snaphsot/create")
+	snapshotDeleteURL = flag.String("snapshot.deleteURL", "", "VictoriaMetrics delete snapshot url. Optional. Will be generated from snapshotCreateURL if not provided. All created snaphosts will be automatically deleted."+
+		"Example: http://victoriametrics:8428/snaphsot/delete")
+	dst = flag.String("dst", "", "Where to put the backup on the remote storage. "+
 		"Example: gcs://bucket/path/to/backup/dir, s3://bucket/path/to/backup/dir or fs:///path/to/local/backup/dir\n"+
 		"-dst can point to the previous backup. In this case incremental backup is performed, i.e. only changed data is uploaded")
 	origin            = flag.String("origin", "", "Optional origin directory on the remote storage with old backup for server-side copying when performing full backup. This speeds up full backups")
@@ -29,6 +35,34 @@ func main() {
 	envflag.Parse()
 	buildinfo.Init()
 
+	if len(*snapshotCreateURL) > 0 {
+		logger.Infof("%s", "Snapshots enabled")
+		logger.Infof("Snapshot create url %s", *snapshotCreateURL)
+		if len(*snapshotDeleteURL) <= 0 {
+			err := flag.Set("snapshot.deleteURL", strings.Replace(*snapshotCreateURL, "/create", "/delete", 1))
+			if err != nil {
+				logger.Fatalf("Failed to set snapshot.deleteURL flag: %v", err)
+			}
+		}
+		logger.Infof("Snapshot delete url %s", *snapshotDeleteURL)
+
+		name, err := snapshot.Create(*snapshotCreateURL)
+		if err != nil {
+			logger.Fatalf("%s", err)
+		}
+		err = flag.Set("snapshotName", name)
+		if err != nil {
+			logger.Fatalf("Failed to set snapshotName flag: %v", err)
+		}
+
+		defer func() {
+			err := snapshot.Delete(*snapshotDeleteURL, name)
+			if err != nil {
+				logger.Fatalf("%s", err)
+			}
+		}()
+	}
+
 	srcFS, err := newSrcFS()
 	if err != nil {
 		logger.Fatalf("%s", err)
@@ -67,7 +101,7 @@ See the docs at https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/a
 
 func newSrcFS() (*fslocal.FS, error) {
 	if len(*snapshotName) == 0 {
-		return nil, fmt.Errorf("`-snapshotName` cannot be empty")
+		return nil, fmt.Errorf("`-snapshotName` or `-snapshot.createURL` must be provided")
 	}
 	snapshotPath := *storageDataPath + "/snapshots/" + *snapshotName
 

app/vmbackup/snapshot/snapshot.go

@@ -0,0 +1,91 @@
+package snapshot
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/logger"
+)
+
+type snapshot struct {
+	Status   string `json:"status"`
+	Snapshot string `json:"snapshot"`
+	Msg      string `json:"msg"`
+}
+
+// Create creates a snapshot and the provided api endpoint and returns
+// the snapshot name
+func Create(createSnapshotURL string) (string, error) {
+	logger.Infof("%s", "Creating snapshot")
+	u, err := url.Parse(createSnapshotURL)
+	if err != nil {
+		return "", err
+	}
+
+	resp, err := http.Get(u.String())
+	if err != nil {
+		return "", err
+	}
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	snap := snapshot{}
+	err = json.Unmarshal(body, &snap)
+	if err != nil {
+		return "", err
+	}
+
+	if snap.Status == "ok" {
+		logger.Infof("Snapshot %s created", snap.Snapshot)
+		return snap.Snapshot, nil
+	} else if snap.Status == "error" {
+		return "", errors.New(snap.Msg)
+	} else {
+		return "", fmt.Errorf("Unkown status: %v", snap.Status)
+	}
+}
+
+// Delete deletes a snapshot and the provided api endpoint returns any failure
+func Delete(deleteSnapshotURL string, snapshotName string) error {
+	logger.Infof("Deleting snapshot %s", snapshotName)
+	formData := url.Values{
+		"snapshot": {snapshotName},
+	}
+
+	u, err := url.Parse(deleteSnapshotURL)
+	if err != nil {
+		return err
+	}
+
+	resp, err := http.PostForm(u.String(), formData)
+	if err != nil {
+		return err
+	}
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+
+	snap := snapshot{}
+	err = json.Unmarshal(body, &snap)
+	if err != nil {
+		return err
+	}
+
+	if snap.Status == "ok" {
+		logger.Infof("Snapshot %s deleted", snapshotName)
+		return nil
+	} else if snap.Status == "error" {
+		return errors.New(snap.Msg)
+	} else {
+		return fmt.Errorf("Unkown status: %v", snap.Status)
+	}
+}

app/vmbackup/snapshot/snapshot_test.go

@@ -0,0 +1,106 @@
+package snapshot
+
+import (
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestCreateSnapshot(t *testing.T) {
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/snapshot/create" {
+			_, err := io.WriteString(w, `{"status":"ok","snapshot":"mysnapshot"}`)
+			if err != nil {
+				t.Fatalf("Failed to write response output: %v", err)
+			}
+		} else {
+			t.Fatalf("Invalid path, got %v", r.URL.Path)
+		}
+	})
+
+	server := httptest.NewServer(http.HandlerFunc(handler))
+	defer server.Close()
+
+	snapshotName, err := Create(server.URL + "/snapshot/create")
+	if err != nil {
+		t.Fatalf("Failed taking snapshot: %v", err)
+	}
+
+	if snapshotName != "mysnapshot" {
+		t.Fatalf("Snapshot name is not correct, got %v", snapshotName)
+	}
+}
+
+func TestCreateSnapshotFailed(t *testing.T) {
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/snapshot/create" {
+			_, err := io.WriteString(w, `{"status":"error","msg":"I am unwell"}`)
+			if err != nil {
+				t.Fatalf("Failed to write response output: %v", err)
+			}
+		} else {
+			t.Fatalf("Invalid path, got %v", r.URL.Path)
+		}
+	})
+
+	server := httptest.NewServer(http.HandlerFunc(handler))
+	defer server.Close()
+
+	snapshotName, err := Create(server.URL + "/snapshot/create")
+	if err == nil {
+		t.Fatalf("Snapshot did not fail, got snapshot: %v", snapshotName)
+	}
+}
+
+func TestDeleteSnapshot(t *testing.T) {
+	snapshotName := "mysnapshot"
+
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/snapshot/delete" {
+			_, err := io.WriteString(w, `{"status":"ok"}`)
+			if err != nil {
+				t.Fatalf("Failed to write response output: %v", err)
+			}
+		} else {
+			t.Fatalf("Invalid path, got %v", r.URL.Path)
+		}
+		if r.FormValue("snapshot") != snapshotName {
+			t.Fatalf("Invalid snapshot name, got %v", snapshotName)
+		}
+	})
+
+	server := httptest.NewServer(http.HandlerFunc(handler))
+	defer server.Close()
+
+	err := Delete(server.URL+"/snapshot/delete", snapshotName)
+	if err != nil {
+		t.Fatalf("Failed to delete snapshot: %v", err)
+	}
+}
+
+func TestDeleteSnapshotFailed(t *testing.T) {
+	snapshotName := "mysnapshot"
+
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.URL.Path == "/snapshot/delete" {
+			_, err := io.WriteString(w, `{"status":"error", "msg":"failed to delete"}`)
+			if err != nil {
+				t.Fatalf("Failed to write response output: %v", err)
+			}
+		} else {
+			t.Fatalf("Invalid path, got %v", r.URL.Path)
+		}
+		if r.FormValue("snapshot") != snapshotName {
+			t.Fatalf("Invalid snapshot name, got %v", snapshotName)
+		}
+	})
+
+	server := httptest.NewServer(http.HandlerFunc(handler))
+	defer server.Close()
+
+	err := Delete(server.URL+"/snapshot/delete", snapshotName)
+	if err == nil {
+		t.Fatalf("Snapshot should have failed, got: %v", err)
+	}
+}