func()

in internal/onetime/hanadiskrestore/hanadiskrestore.go [545:648]

• 93 lines of code
• 30 McCabe index (conditional complexity)

func (r *Restorer) checkPreConditions(ctx context.Context, cp *ipb.CloudProperties, checkDataDir getDataPaths, checkLogDir getLogPaths, exec commandlineexecutor.Execute) error {
	var err error
	if r.baseDataPath, r.logicalDataPath, r.physicalDataPath, err = checkDataDir(ctx, exec); err != nil {
		return err
	}
	if r.baseLogPath, r.logicalLogPath, r.physicalLogPath, err = checkLogDir(ctx, exec); err != nil {
		return err
	}
	log.CtxLogger(ctx).Infow("Checking preconditions", "Data directory", r.baseDataPath, "Data file system",
		r.logicalDataPath, "Data physical volume", r.physicalDataPath, "Log directory", r.baseLogPath,
		"Log file system", r.logicalLogPath, "Log physical volume", r.physicalLogPath)

	if strings.Contains(r.physicalDataPath, r.physicalLogPath) {
		return fmt.Errorf("unsupported: HANA data and HANA log are on the same physical disk - %s", r.physicalDataPath)
	}

	if r.DataDiskName == "" || r.DataDiskZone == "" || r.isGroupSnapshot {
		if err := r.readDiskMapping(ctx, cp, &instanceinfo.PhysicalPathReader{OS: runtime.GOOS}); err != nil {
			return fmt.Errorf("failed to read disks backing /hana/data: %v", err)
		}
	}

	// Verify the disk is attached to the instance.
	if !r.isGroupSnapshot {
		dev, ok, err := r.gceService.DiskAttachedToInstance(r.Project, r.DataDiskZone, cp.GetInstanceName(), r.DataDiskName)
		if err != nil {
			return fmt.Errorf("failed to verify if disk %v is attached to the instance", r.DataDiskName)
		}
		if !ok {
			return fmt.Errorf("the disk data-disk-name=%v is not attached to the instance, please pass the current data disk name", r.DataDiskName)
		}
		r.DataDiskDeviceName = dev
	} else {
		if ok, err := r.multiDisksAttachedToInstance(ctx, cp, exec); err != nil {
			return fmt.Errorf("failed to verify if disks are attached to the instance: %v", err)
		} else if !ok {
			return fmt.Errorf("the disks are not attached to the instance, please pass the verify the disks provided are attached to the instance")
		}
	}

	// Verify the snapshot is present.
	if !r.isGroupSnapshot {
		if r.computeService == nil {
			return fmt.Errorf("compute service is nil")
		}
		snapshot, err := r.computeService.Snapshots.Get(r.Project, r.SourceSnapshot).Do()
		if err != nil {
			return fmt.Errorf("failed to check if source-snapshot=%v is present: %v", r.SourceSnapshot, err)
		}
		r.extractLabels(ctx, snapshot)
	} else {
		snapshotList, err := r.gceService.ListSnapshots(ctx, r.Project)
		if err != nil {
			return fmt.Errorf("failed to list snapshots: %v", err)
		}

		var numOfSnapshots int
		for _, snapshot := range snapshotList.Items {
			if snapshot.Labels["goog-sapagent-isg"] == r.GroupSnapshot {
				r.extractLabels(ctx, snapshot)
				numOfSnapshots++
			}
		}
		if numOfSnapshots != len(r.disks) {
			return fmt.Errorf("did not get required number of snapshots for restoration, wanted: %v, got: %v", len(r.disks), numOfSnapshots)
		}
	}

	if r.isGroupSnapshot && r.NewDiskPrefix != "" {
		for diskNum := range len(r.disks) {
			newDiskName := fmt.Sprintf("%s-%s", r.NewDiskPrefix, fmt.Sprintf("%d", diskNum+1))
			disk, err := r.gceService.GetDisk(r.Project, r.DataDiskZone, newDiskName)
			if disk != nil && err == nil {
				return fmt.Errorf("disk with name %v already exists, please choose a different prefix", newDiskName)
			}
		}
	}

	if r.NewDiskType == "" {
		if !r.isGroupSnapshot {
			d, err := r.computeService.Disks.Get(r.Project, r.DataDiskZone, r.DataDiskName).Do()
			if err != nil {
				return fmt.Errorf("failed to read data disk type: %v", err)
			}
			r.NewDiskType = d.Type
			log.CtxLogger(ctx).Infow("New disk type will be same as the data-disk-name", "diskType", r.NewDiskType)
		} else {
			disk, err := r.gceService.GetDisk(r.Project, r.DataDiskZone, r.disks[0].disk.GetDiskName())
			if err != nil {
				return fmt.Errorf("failed to read data disk type: %v", err)
			}
			r.NewDiskType = disk.Type
			log.CtxLogger(ctx).Infow("New disk type will be same as the data-disk-name", "diskType", r.NewDiskType)
		}
	} else {
		r.NewDiskType = fmt.Sprintf("projects/%s/zones/%s/diskTypes/%s", r.Project, r.DataDiskZone, r.NewDiskType)
	}

	if err := r.validateDisksBelongToCG(ctx); err != nil {
		return err
	}

	return nil
}