server

type Configuration struct {
	// Server listening address.
	ListenAddress string `yaml:"listenAddress" validate:"nonzero"`

	// Retry mechanism configuration.
	Retry retry.Configuration `yaml:"retry"`

	// Whether keep alives are enabled on connections.
	KeepAliveEnabled *bool `yaml:"keepAliveEnabled"`

	// KeepAlive period.
	KeepAlivePeriod *time.Duration `yaml:"keepAlivePeriod"`

	// TLS configuration
	TLS *TLSConfiguration `yaml:"tls"`
}

type Handler interface {
	// Handle handles the data received on the connection, this function
	// should be blocking until the connection is closed or received error.
	Handle(conn net.Conn)

	// Close closes the handler.
	Close()
}

type Options interface {
	// SetInstrumentOptions sets the instrument options
	SetInstrumentOptions(value instrument.Options) Options

	// InstrumentOptions returns the instrument options
	InstrumentOptions() instrument.Options

	// SetRetryOptions sets the retry options
	SetRetryOptions(value retry.Options) Options

	// RetryOptions returns the retry options
	RetryOptions() retry.Options

	// SetTCPConnectionKeepAlive sets the keep alive state for tcp connections.
	SetTCPConnectionKeepAlive(value bool) Options

	// TCPConnectionKeepAlive returns the keep alive state for tcp connections.
	TCPConnectionKeepAlive() bool

	// SetTCPConnectionKeepAlivePeriod sets the keep alive period for tcp connections.
	// NB(xichen): on Linux this modifies both the idle time (i.e,. the time when the
	// last packet is sent from the client and when the first keepAlive probe is sent)
	// as well as the interval between keepAlive probes.
	SetTCPConnectionKeepAlivePeriod(value time.Duration) Options

	// TCPConnectionKeepAlivePeriod returns the keep alive period for tcp connections.
	TCPConnectionKeepAlivePeriod() time.Duration

	// SetListenerOptions sets the listener options for the server.
	SetListenerOptions(value xnet.ListenerOptions) Options

	// ListenerOptions sets the listener options for the server.
	ListenerOptions() xnet.ListenerOptions

	// SetTLSOptions sets the tls options for the server
	SetTLSOptions(value xtls.Options) Options

	// TLSOptions returns the tls options for the server
	TLSOptions() xtls.Options
}

type Server interface {
	// ListenAndServe forever listens to new incoming connections and
	// handles data from those connections.
	ListenAndServe() error

	// Serve accepts and handles incoming connections on the listener l forever.
	Serve(l net.Listener) error

	// Close closes the server.
	Close()
}

type StoppableServer interface {
	Server
	Stop()
}

type TLSConfiguration struct {
	// Mode is the tls server mode
	// disabled - allows plaintext connections only
	// permissive - allows both plaintext and TLS connections
	// enforced - allows TLS connections only
	Mode string `yaml:"mode" validate:"nonzero,regexp=^(disabled|permissive|enforced)$"`

	// CertFile path to a server certificate file
	CertFile string `yaml:"certFile"`

	// KeyFile path to a server key file
	KeyFile string `yaml:"keyFile"`

	// ClientCAFile path to a CA file for verifying clients
	ClientCAFile string `yaml:"clientCAFile"`

	// CertificatesTTL is a time duration certificates are stored in memory
	CertificatesTTL time.Duration `yaml:"certificatesTTL"`

	// MutualTLSEnabled sets mTLS
	MutualTLSEnabled bool `yaml:"mTLSEnabled"`
}