feat: support --skip-if-unchanged

internal/orchestrator/repo/repo.go

@@ -169,13 +169,13 @@ func (r *RepoOrchestrator) Backup(ctx context.Context, plan *v1.Plan, progressCa
 
 	ctx, flush := forwardResticLogs(ctx)
 	defer flush()
-	l.Debug("starting backup", zap.String("repo", r.repoConfig.Id), zap.String("plan", plan.Id))
+	l.Debug("starting backup", zap.String("plan", plan.Id))
 	summary, err := r.repo.Backup(ctx, plan.Paths, progressCallback, opts...)
 	if err != nil {
 		return summary, fmt.Errorf("failed to backup: %w", err)
 	}
 
-	l.Debug("backup completed", zap.String("repo", r.repoConfig.Id), zap.Duration("duration", time.Since(startTime)))
+	l.Debug("backup completed", zap.Duration("duration", time.Since(startTime)))
 	return summary, nil
 }
 

internal/orchestrator/tasks/hookvars.go

@@ -41,6 +41,8 @@ func (v HookVars) EventName(cond v1.Hook_Condition) string {
 		return "snapshot warning"
 	case v1.Hook_CONDITION_SNAPSHOT_SUCCESS:
 		return "snapshot success"
+	case v1.Hook_CONDITION_SNAPSHOT_SKIPPED:
+		return "snapshot skipped"
 	case v1.Hook_CONDITION_CHECK_START:
 		return "check start"
 	case v1.Hook_CONDITION_CHECK_ERROR:

internal/orchestrator/tasks/hookvars_test.go

@@ -0,0 +1,23 @@
+package tasks
+
+import (
+	"testing"
+
+	v1 "github.com/garethgeorge/backrest/gen/go/v1"
+)
+
+func TestHookVarsEventName(t *testing.T) {
+	// for every value of condition, check that the event name is correct
+	values := v1.Hook_Condition(0).Descriptor().Values()
+	for i := 0; i < values.Len(); i++ {
+		condition := v1.Hook_Condition(values.Get(i).Number())
+		if condition == v1.Hook_CONDITION_UNKNOWN {
+			continue
+		}
+
+		vars := HookVars{}
+		if vars.EventName(condition) == "unknown" {
+			t.Errorf("unexpected event name for condition %v", condition)
+		}
+	}
+}

internal/orchestrator/tasks/taskbackup.go

@@ -212,11 +212,6 @@ func (t *BackupTask) Run(ctx context.Context, st ScheduledTask, runner TaskRunne
 			v1.Hook_CONDITION_SNAPSHOT_WARNING,
 			v1.Hook_CONDITION_SNAPSHOT_END,
 		}, vars)
-	} else {
-		runner.ExecuteHooks(ctx, []v1.Hook_Condition{
-			v1.Hook_CONDITION_SNAPSHOT_SUCCESS,
-			v1.Hook_CONDITION_SNAPSHOT_END,
-		}, vars)
 	}
 
 	op.SnapshotId = summary.SnapshotId
@@ -227,15 +222,28 @@ func (t *BackupTask) Run(ctx context.Context, st ScheduledTask, runner TaskRunne
 
 	l.Info("backup complete", zap.String("plan", plan.Id), zap.Duration("duration", time.Since(startTime)), zap.Any("summary", backupOp.OperationBackup.LastStatus))
 
-	// schedule followup tasks
-	at := time.Now()
-	if _, ok := plan.Retention.GetPolicy().(*v1.RetentionPolicy_PolicyKeepAll); plan.Retention != nil && !ok {
-		if err := runner.ScheduleTask(NewOneoffForgetTask(t.RepoID(), t.PlanID(), op.FlowId, at), TaskPriorityForget); err != nil {
-			return fmt.Errorf("failed to schedule forget task: %w", err)
+	if summary.SnapshotId == "" { // support --skip-if-unchanged which returns an operation with an empty snapshot ID
+		op.DisplayMessage = "No snapshot added, possibly due to no changes in the source data."
+		runner.ExecuteHooks(ctx, []v1.Hook_Condition{
+			v1.Hook_CONDITION_SNAPSHOT_SKIPPED,
+			v1.Hook_CONDITION_SNAPSHOT_END,
+		}, vars)
+	} else {
+		runner.ExecuteHooks(ctx, []v1.Hook_Condition{
+			v1.Hook_CONDITION_SNAPSHOT_SUCCESS,
+			v1.Hook_CONDITION_SNAPSHOT_END,
+		}, vars)
+
+		// schedule followup tasks if a snapshot was added
+		at := time.Now()
+		if _, ok := plan.Retention.GetPolicy().(*v1.RetentionPolicy_PolicyKeepAll); plan.Retention != nil && !ok {
+			if err := runner.ScheduleTask(NewOneoffForgetTask(t.RepoID(), t.PlanID(), op.FlowId, at), TaskPriorityForget); err != nil {
+				return fmt.Errorf("failed to schedule forget task: %w", err)
+			}
+		}
+		if err := runner.ScheduleTask(NewOneoffIndexSnapshotsTask(t.RepoID(), at), TaskPriorityIndexSnapshots); err != nil {
+			return fmt.Errorf("failed to schedule index snapshots task: %w", err)
 		}
-	}
-	if err := runner.ScheduleTask(NewOneoffIndexSnapshotsTask(t.RepoID(), at), TaskPriorityIndexSnapshots); err != nil {
-		return fmt.Errorf("failed to schedule index snapshots task: %w", err)
 	}
 
 	return nil

pkg/restic/outputs.go

@@ -116,10 +116,7 @@ type BackupProgressEntry struct {
 }
 
 func (b *BackupProgressEntry) Validate() error {
-	if b.MessageType == "summary" {
-		if b.SnapshotId == "" {
-			return errors.New("summary message must have snapshot_id")
-		}
+	if b.MessageType == "summary" && b.SnapshotId != "" {
 		if err := ValidateSnapshotId(b.SnapshotId); err != nil {
 			return err
 		}

proto/v1/config.proto

@@ -54,6 +54,8 @@ message Plan {
   RetentionPolicy retention = 7 [json_name="retention"]; // retention policy for snapshots.
   repeated Hook hooks = 8 [json_name="hooks"]; // hooks to run on events for this plan.
   repeated string backup_flags = 10 [json_name="backup_flags"]; // extra flags to set when running a backup command.
+  bool skip_if_unchanged = 13 [json_name="skipIfUnchanged"]; // skip the backup if no changes are detected.
+  reserved 3, 6, 11; // deprecated
 }
 
 message CommandPrefix {
@@ -132,6 +134,7 @@ message Hook {
     CONDITION_SNAPSHOT_ERROR = 4; // snapshot failed.
     CONDITION_SNAPSHOT_WARNING = 5; // snapshot completed with warnings.
     CONDITION_SNAPSHOT_SUCCESS = 6; // snapshot succeeded.
+    CONDITION_SNAPSHOT_SKIPPED = 7; // snapshot was skipped e.g. due to no changes.
 
     // prune conditions
     CONDITION_PRUNE_START = 100; // prune started.

webui/gen/ts/v1/config_pb.ts

@@ -342,6 +342,13 @@ export class Plan extends Message<Plan> {
    */
   backupFlags: string[] = [];
 
+  /**
+   * skip the backup if no changes are detected.
+   *
+   * @generated from field: bool skip_if_unchanged = 13;
+   */
+  skipIfUnchanged = false;
+
   constructor(data?: PartialMessage<Plan>) {
     super();
     proto3.util.initPartial(data, this);
@@ -359,6 +366,7 @@ export class Plan extends Message<Plan> {
     { no: 7, name: "retention", kind: "message", T: RetentionPolicy },
     { no: 8, name: "hooks", kind: "message", T: Hook, repeated: true },
     { no: 10, name: "backup_flags", jsonName: "backup_flags", kind: "scalar", T: 9 /* ScalarType.STRING */, repeated: true },
+    { no: 13, name: "skip_if_unchanged", kind: "scalar", T: 8 /* ScalarType.BOOL */ },
   ]);
 
   static fromBinary(bytes: Uint8Array, options?: Partial<BinaryReadOptions>): Plan {
@@ -986,6 +994,13 @@ export enum Hook_Condition {
    */
   SNAPSHOT_SUCCESS = 6,
 
+  /**
+   * snapshot was skipped e.g. due to no changes.
+   *
+   * @generated from enum value: CONDITION_SNAPSHOT_SKIPPED = 7;
+   */
+  SNAPSHOT_SKIPPED = 7,
+
   /**
    * prune conditions
    *
@@ -1041,6 +1056,7 @@ proto3.util.setEnumType(Hook_Condition, "v1.Hook.Condition", [
   { no: 4, name: "CONDITION_SNAPSHOT_ERROR" },
   { no: 5, name: "CONDITION_SNAPSHOT_WARNING" },
   { no: 6, name: "CONDITION_SNAPSHOT_SUCCESS" },
+  { no: 7, name: "CONDITION_SNAPSHOT_SKIPPED" },
   { no: 100, name: "CONDITION_PRUNE_START" },
   { no: 101, name: "CONDITION_PRUNE_ERROR" },
   { no: 102, name: "CONDITION_PRUNE_SUCCESS" },

webui/src/components/OperationRow.tsx

@@ -495,7 +495,9 @@ const BackupOperationStatus = ({
       <>
         <Typography.Text>
           <Typography.Text strong>Snapshot ID: </Typography.Text>
-          {normalizeSnapshotId(sum.snapshotId!)}
+          {sum.snapshotId !== ""
+            ? normalizeSnapshotId(sum.snapshotId!)
+            : "No Snapshot Created"}
         </Typography.Text>
         <Row gutter={16}>
           <Col span={8}>

webui/src/components/OperationTree.tsx

@@ -85,9 +85,12 @@ export const OperationTree = ({
         event === OperationEventType.EVENT_UPDATED
       ) {
         for (const flowID of flowIDs) {
-          const displayInfo = displayInfoForFlow(
-            logState.getByFlowID(flowID) || []
-          );
+          const ops = logState.getByFlowID(flowID);
+          if (!ops || ops[0].op.case === "operationRunHook") {
+            continue;
+          }
+
+          const displayInfo = displayInfoForFlow(ops);
           if (!displayInfo.hidden) {
             backupInfoByFlowID.set(flowID, displayInfo);
           } else {

webui/src/state/oplog.ts

@@ -60,6 +60,7 @@ export const unsubscribeFromOperations = (
 export const shouldHideOperation = (operation: Operation) => {
   return (
     operation.op.case === "operationStats" ||
+    (operation.status === OperationStatus.STATUS_SUCCESS && operation.op.case === "operationBackup" && !operation.snapshotId) ||
     shouldHideStatus(operation.status)
   );
 };

webui/src/views/PlanView.tsx

@@ -117,7 +117,7 @@ export const PlanView = ({ plan }: React.PropsWithChildren<{ plan: Plan }>) => {
           },
           {
             key: "2",
-            label: "Operation List",
+            label: "Full Operation History",
             children: (
               <>
                 <h2>Backup Action History</h2>

webui/src/views/RepoView.tsx

@@ -125,7 +125,7 @@ export const RepoView = ({ repo }: React.PropsWithChildren<{ repo: Repo }>) => {
     },
     {
       key: "2",
-      label: "Operation List",
+      label: "Full Operation History",
       children: (
         <>
           <h3>Backup Action History</h3>