You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: health_checker.go
    path of file: ./repos/cockroach/pkg/cmd/roachtest/roachtestutil
    
    the code of the file until where you have to start completion: // Copyright 2023 The Cockroach Authors.
//
// Use of this software is governed by the Business Source License
// included in the file licenses/BSL.txt.
//
// As of the Change Date specified in that file, in accordance with
// the Business Source License, use of t
    
func (hc *HealthChecker) Runner(ctx context.Context) (err error) {
	var nodeIdx int
	logger, err := hc.t.L().ChildLogger("health")
	if err != nil {
		return err
	}
	defer func() {
		logger.Printf("health check terminated on node %d with %v\n", nodeIdx, err)
	}()

	ticker := time.NewTicker(5 * time.Second)
	defer ticker.Stop()
	for {
		select {
		case <-ctx.Done():
			return ctx.Err()
		case <-hc.doneCh:
			return nil
		case <-ticker.C:
		}

		tBegin := timeutil.Now()

		nodeIdx = 1 + rand.Intn(len(hc.nodes))
		db, err := hc.c.ConnE(ctx, hc.t.L(), nodeIdx)
		if err != nil {
			return err
		}
		// TODO(tschottdorf): remove replicate queue failures when the cluster first starts.
		// Ditto queue.raftsnapshot.process.failure.
		_, err = db.Exec(`USE system`)
		if err != nil {
			return err
		}
		rows, err := db.QueryContext(ctx, `SELECT * FROM crdb_internal.gossip_alerts ORDER BY node_id ASC, store_id ASC `)
		_ = db.Close()
		if err != nil {
			return err
		}
		var rr gossipAlerts
		for rows.Next() {
			a := gossipAlert{StoreID: -1}
			var storeID gosql.NullInt64
			if err := rows.Scan(&a.NodeID, &storeID, &a.Category, &a.Description, &a.Value); err != nil {
				return err
			}
			if storeID.Valid {
				a.StoreID = int(storeID.Int64)
			}
			rr = append(rr, a)
		}
		if len(rr) > 0 {
			logger.Printf(rr.String() + "\n")
			// TODO(tschottdorf): see method comment.
			// return errors.New(rr.String())
		}

		if elapsed := timeutil.Since(tBegin); elapsed > 10*time.Second {
			err := errors.Errorf("health check against node %d took %s", nodeIdx, elapsed)
			logger.Printf("%+v", err)
			// TODO(tschottdorf): see method comment.
			// return err
		}
	}
}