func restorePolicies()

in monitoring/alert/alert.go [186:269]
77 lines of code
16 McCabe index (conditional complexity)

func restorePolicies(w io.Writer, projectID string, r io.Reader) error {
	b := backup{}
	if err := json.NewDecoder(r).Decode(&b); err != nil {
		return err
	}
	sameProject := projectID == b.ProjectID

	ctx := context.Background()

	alertClient, err := monitoring.NewAlertPolicyClient(ctx)
	if err != nil {
		return err
	}
	defer alertClient.Close()
	channelClient, err := monitoring.NewNotificationChannelClient(ctx)
	if err != nil {
		return err
	}
	defer channelClient.Close()

	// When a channel is recreated, rather than updated, it will get
	// a new name.  We have to update the AlertPolicy with the new
	// name.  channelNames keeps track of the new names.
	channelNames := make(map[string]string)
	for _, c := range b.Channels {
		fmt.Fprintf(w, "Updating channel %q\n", c.GetDisplayName())
		c.VerificationStatus = monitoringpb.NotificationChannel_VERIFICATION_STATUS_UNSPECIFIED
		updated := false
		if sameProject {
			req := &monitoringpb.UpdateNotificationChannelRequest{
				NotificationChannel: c.NotificationChannel,
			}
			_, err := channelClient.UpdateNotificationChannel(ctx, req)
			if err == nil {
				updated = true
			}
		}
		if !updated {
			req := &monitoringpb.CreateNotificationChannelRequest{
				Name:                "projects/" + projectID,
				NotificationChannel: c.NotificationChannel,
			}
			oldName := c.GetName()
			c.Name = ""
			newC, err := channelClient.CreateNotificationChannel(ctx, req)
			if err != nil {
				return err
			}
			channelNames[oldName] = newC.GetName()
		}
	}

	for _, policy := range b.AlertPolicies {
		fmt.Fprintf(w, "Updating alert %q\n", policy.GetDisplayName())
		policy.CreationRecord = nil
		policy.MutationRecord = nil
		for i, aChannel := range policy.GetNotificationChannels() {
			if c, ok := channelNames[aChannel]; ok {
				policy.NotificationChannels[i] = c
			}
		}
		updated := false
		if sameProject {
			req := &monitoringpb.UpdateAlertPolicyRequest{
				AlertPolicy: policy.AlertPolicy,
			}
			_, err := alertClient.UpdateAlertPolicy(ctx, req)
			if err == nil {
				updated = true
			}
		}
		if !updated {
			req := &monitoringpb.CreateAlertPolicyRequest{
				Name:        "projects/" + projectID,
				AlertPolicy: policy.AlertPolicy,
			}
			if _, err = alertClient.CreateAlertPolicy(ctx, req); err != nil {
				log.Fatal(err)
			}
		}
	}
	fmt.Fprintf(w, "Successfully restored alerts.")
	return nil
}