func NewDefaultConfig() *Config {
	return &Config{
		TTL:                env.GetOrDefaultInt(EnvTTL, 10),
		PropagationTimeout: env.GetOrDefaultSecond(EnvPropagationTimeout, 10*time.Minute),
		PollingInterval:    env.GetOrDefaultSecond(EnvPollingInterval, 10*time.Second),
	}
}
NewDefaultConfig returns a default configuration for the DNSProvider.
package designate
import (
	"errors"
	"fmt"
	"log"
	"os"
	"sync"
	"time"
	"github.com/go-acme/lego/v4/challenge/dns01"
	"github.com/go-acme/lego/v4/platform/config/env"
	"github.com/gophercloud/gophercloud"
	"github.com/gophercloud/gophercloud/openstack"
	"github.com/gophercloud/gophercloud/openstack/dns/v2/recordsets"
	"github.com/gophercloud/gophercloud/openstack/dns/v2/zones"
	"github.com/gophercloud/utils/openstack/clientconfig"
)
const (
	envNamespace = "DESIGNATE_"
	EnvTTL                = envNamespace + "TTL"
	EnvPropagationTimeout = envNamespace + "PROPAGATION_TIMEOUT"
	EnvPollingInterval    = envNamespace + "POLLING_INTERVAL"
	envNamespaceClient = "OS_"
	EnvAuthURL       = envNamespaceClient + "AUTH_URL"
	EnvUsername      = envNamespaceClient + "USERNAME"
	EnvPassword      = envNamespaceClient + "PASSWORD"
	EnvUserID        = envNamespaceClient + "USER_ID"
	EnvAppCredID     = envNamespaceClient + "APPLICATION_CREDENTIAL_ID"
	EnvAppCredName   = envNamespaceClient + "APPLICATION_CREDENTIAL_NAME"
	EnvAppCredSecret = envNamespaceClient + "APPLICATION_CREDENTIAL_SECRET"
	EnvTenantName    = envNamespaceClient + "TENANT_NAME"
	EnvRegionName    = envNamespaceClient + "REGION_NAME"
	EnvProjectID     = envNamespaceClient + "PROJECT_ID"
	EnvCloud         = envNamespaceClient + "CLOUD"
)
type Config struct {
	PropagationTimeout time.Duration
	PollingInterval    time.Duration
	TTL                int
	opts               gophercloud.AuthOptions
}