func FileChecker(f string) health.Checker {
	return health.CheckFunc(func() error {
		if _, err := os.Stat(f); err == nil {
			return errors.New("file exists")
		}
		return nil
	})
}
FileChecker checks the existence of a file and returns an error
if the file exists.
package checks
import (
	"errors"
	"net"
	"net/http"
	"os"
	"strconv"
	"time"
	"github.com/docker/distribution/health"
)