provisioning: only update dashboard if hash of json changed

devenv/setup.sh

@@ -5,7 +5,7 @@ bulkDashboard() {
     requiresJsonnet
 
     COUNTER=0
-    MAX=400
+    MAX=4
     while [  $COUNTER -lt $MAX ]; do
         jsonnet -o "dashboards/bulk-testing/dashboard${COUNTER}.json" -e "local bulkDash = import 'dashboards/bulk-testing/bulkdash.jsonnet'; bulkDash + {  uid: 'uid-${COUNTER}',  title: 'title-${COUNTER}' }"
         let COUNTER=COUNTER+1

pkg/models/dashboards.go

@@ -254,6 +254,7 @@ type DashboardProvisioning struct {
 	DashboardId int64
 	Name        string
 	ExternalId  string
+	CheckSum    string
 	Updated     int64
 }
 

pkg/services/provisioning/dashboards/file_reader.go

@@ -4,12 +4,14 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
 	"time"
 
 	"github.com/grafana/grafana/pkg/services/dashboards"
+	"github.com/grafana/grafana/pkg/util"
 
 	"github.com/grafana/grafana/pkg/bus"
 
@@ -161,13 +163,18 @@ func (fr *fileReader) saveDashboard(path string, folderId int64, fileInfo os.Fil
 	provisionedData, alreadyProvisioned := provisionedDashboardRefs[path]
 	upToDate := alreadyProvisioned && provisionedData.Updated >= resolvedFileInfo.ModTime().Unix()
 
-	dash, err := fr.readDashboardFromFile(path, resolvedFileInfo.ModTime(), folderId)
+	jsonFile, err := fr.readDashboardFromFile(path, resolvedFileInfo.ModTime(), folderId)
 	if err != nil {
 		fr.log.Error("failed to load dashboard from ", "file", path, "error", err)
 		return provisioningMetadata, nil
 	}
 
+	if provisionedData != nil && jsonFile.checkSum == provisionedData.CheckSum {
+		upToDate = true
+	}
+
 	// keeps track of what uid's and title's we have already provisioned
+	dash := jsonFile.dashboard
 	provisioningMetadata.uid = dash.Dashboard.Uid
 	provisioningMetadata.title = dash.Dashboard.Title
 
@@ -185,7 +192,13 @@ func (fr *fileReader) saveDashboard(path string, folderId int64, fileInfo os.Fil
 	}
 
 	fr.log.Debug("saving new dashboard", "file", path)
-	dp := &models.DashboardProvisioning{ExternalId: path, Name: fr.Cfg.Name, Updated: resolvedFileInfo.ModTime().Unix()}
+	dp := &models.DashboardProvisioning{
+		ExternalId: path,
+		Name:       fr.Cfg.Name,
+		Updated:    resolvedFileInfo.ModTime().Unix(),
+		CheckSum:   jsonFile.checkSum,
+	}
+
 	_, err = fr.dashboardService.SaveProvisionedDashboard(dash, dp)
 	return provisioningMetadata, err
 }
@@ -283,14 +296,30 @@ func validateWalkablePath(fileInfo os.FileInfo) (bool, error) {
 	return true, nil
 }
 
-func (fr *fileReader) readDashboardFromFile(path string, lastModified time.Time, folderId int64) (*dashboards.SaveDashboardDTO, error) {
+type dashboardJsonFile struct {
+	dashboard    *dashboards.SaveDashboardDTO
+	checkSum     string
+	lastModified time.Time
+}
+
+func (fr *fileReader) readDashboardFromFile(path string, lastModified time.Time, folderId int64) (*dashboardJsonFile, error) {
 	reader, err := os.Open(path)
 	if err != nil {
 		return nil, err
 	}
 	defer reader.Close()
 
-	data, err := simplejson.NewFromReader(reader)
+	all, err := ioutil.ReadAll(reader)
+	if err != nil {
+		return nil, err
+	}
+
+	checkSum, err := util.Md5SumString(string(all))
+	if err != nil {
+		return nil, err
+	}
+
+	data, err := simplejson.NewJson(all)
 	if err != nil {
 		return nil, err
 	}
@@ -300,7 +329,11 @@ func (fr *fileReader) readDashboardFromFile(path string, lastModified time.Time,
 		return nil, err
 	}
 
-	return dash, nil
+	return &dashboardJsonFile{
+		dashboard:    dash,
+		checkSum:     checkSum,
+		lastModified: lastModified,
+	}, nil
 }
 
 type provisioningMetadata struct {
@@ -328,7 +361,6 @@ func (checker provisioningSanityChecker) track(pm provisioningMetadata) {
 	if len(pm.title) > 0 {
 		checker.titleUsage[pm.title] += 1
 	}
-
 }
 
 func (checker provisioningSanityChecker) logWarnings(log log.Logger) {
@@ -343,5 +375,4 @@ func (checker provisioningSanityChecker) logWarnings(log log.Logger) {
 			log.Error("the same 'title' is used more than once", "title", title, "provider", checker.provisioningProvider)
 		}
 	}
-
 }

pkg/services/sqlstore/migrations/dashboard_mig.go

@@ -211,4 +211,8 @@ func addDashboardMigration(mg *Migrator) {
 		"name":         "name",
 		"external_id":  "external_id",
 	})
+
+	mg.AddMigration("Add check_sum column", NewAddColumnMigration(dashboardExtrasTableV2, &Column{
+		Name: "check_sum", Type: DB_NVarchar, Length: 32, Nullable: true,
+	}))
 }

pkg/util/md5.go

+package util
+
+import (
+	"crypto/md5"
+	"encoding/hex"
+	"io"
+	"strings"
+)
+
+// Md5Sum calculates the md5sum of a stream
+func Md5Sum(reader io.Reader) (string, error) {
+	var returnMD5String string
+	hash := md5.New()
+	if _, err := io.Copy(hash, reader); err != nil {
+		return returnMD5String, err
+	}
+	hashInBytes := hash.Sum(nil)[:16]
+	returnMD5String = hex.EncodeToString(hashInBytes)
+	return returnMD5String, nil
+}
+
+// Md5Sum calculates the md5sum of a string
+func Md5SumString(input string) (string, error) {
+	buffer := strings.NewReader(input)
+	return Md5Sum(buffer)
+}

pkg/util/md5_test.go

+package util
+
+import "testing"
+
+func TestMd5Sum(t *testing.T) {
+	input := "dont hash passwords with md5"
+
+	have, err := Md5SumString(input)
+	if err != nil {
+		t.Fatal("expected err to be nil")
+	}
+
+	want := "2d6a56c82d09d374643b926d3417afba"
+	if have != want {
+		t.Fatalf("expected: %s got: %s", want, have)
+	}
+}