dnscheck

type EmptyMetrics struct{}

type Interface interface {
	// Check saves the information about a client's request and returns the
	// appropriate response.  If req is not the right type of request or not
	// a request for the appropriate check domain, both resp and err are nil.
	//
	// All arguments must be non-nil.  req must contain one question, which
	// should be either an A or an AAAA one.
	Check(ctx context.Context, req *dns.Msg, ri *agd.RequestInfo) (resp *dns.Msg, err error)
}

type Metrics interface {
	// HandleError handles the total number of errors by type.  reqType must be
	// [reqMtrcTypeDNS] or [reqMtrcTypeHTTP].  errType must be either
	// [errMtrcTypeTimeout], [errMtrcTypeRatelimit], [errMtrcTypeOther] or an
	// empty string.
	HandleError(ctx context.Context, reqType, errType string)

	// HandleRequest handles the total number of requests by type.  reqType must
	// be [reqMtrcTypeDNS] or [reqMtrcTypeHTTP].
	HandleRequest(ctx context.Context, reqType string, isValid bool)
}

type RemoteKV struct {
	// contains filtered or unexported fields
}

type RemoteKVConfig struct {
	// Logger is used to log the operation of the DNS checker.
	Logger *slog.Logger

	// Messages is the message constructor used to create DNS responses with
	// IPv4 and IPv6 IPs.
	Messages *dnsmsg.Constructor

	// Metrics is used for the collection of the DNSCheck service statistics.
	Metrics Metrics

	// RemoteKV for DNS server checking.
	RemoteKV remotekv.Interface

	// ErrColl is the error collector that is used to collect non-critical
	// errors.
	ErrColl errcoll.Interface

	// Domains are the lower-cased domain names used to detect DNS check requests.
	Domains []string

	// NodeLocation is the location of this server node.
	NodeLocation string

	// NodeName is the name of this server node.
	NodeName string

	// IPv4 are the IPv4 addresses to respond with to A requests.
	IPv4 []netip.Addr

	// IPv6 are the IPv6 addresses to respond with to AAAA requests.
	IPv6 []netip.Addr
}