coredns/plugin/pkg/proxy/errors.go

package proxy

import (
	"errors"
	"time"
)

var (
	// ErrNoHealthy means no healthy proxies left.
	ErrNoHealthy = errors.New("no healthy proxies")
	// ErrNoForward means no forwarder defined.
	ErrNoForward = errors.New("no forwarder defined")
	// ErrCachedClosed means cached connection was closed by peer.
	ErrCachedClosed = errors.New("cached connection was closed by peer")
	// ErrUnsupportedRequest means the proxy transport cannot represent the request.
	ErrUnsupportedRequest = errors.New("proxy: unsupported request")
)

// Options holds various Options that can be set.
type Options struct {
	// ForceTCP use TCP protocol for upstream DNS request. Has precedence over PreferUDP flag
	ForceTCP bool
	// PreferUDP use UDP protocol for upstream DNS request.
	PreferUDP bool
	// HCRecursionDesired sets recursion desired flag for Proxy healthcheck requests
	HCRecursionDesired bool
	// HCDomain sets domain for Proxy healthcheck requests
	HCDomain string
	// TLSConnectDeadline bounds the TCP dial and TLS handshake for DoT, not the DNS exchange.
	// A zero value leaves the adaptive dial timeout and caller context as the only limits.
	TLSConnectDeadline time.Time
}