120 lines
2.9 KiB
Go
120 lines
2.9 KiB
Go
/*
|
|
Package grpc provides a Handler and client for agent gRPC connections.
|
|
*/
|
|
package grpc
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
|
|
"google.golang.org/grpc"
|
|
)
|
|
|
|
// NewHandler returns a gRPC server that accepts connections from Handle(conn).
|
|
// The register function will be called with the grpc.Server to register
|
|
// gRPC services with the server.
|
|
func NewHandler(addr net.Addr, register func(server *grpc.Server)) *Handler {
|
|
// We don't need to pass tls.Config to the server since it's multiplexed
|
|
// behind the RPC listener, which already has TLS configured.
|
|
srv := grpc.NewServer(
|
|
grpc.StatsHandler(newStatsHandler(defaultMetrics)),
|
|
grpc.StreamInterceptor((&activeStreamCounter{metrics: defaultMetrics}).Intercept),
|
|
)
|
|
register(srv)
|
|
|
|
lis := &chanListener{addr: addr, conns: make(chan net.Conn), done: make(chan struct{})}
|
|
return &Handler{srv: srv, listener: lis}
|
|
}
|
|
|
|
// Handler implements a handler for the rpc server listener, and the
|
|
// agent.Component interface for managing the lifecycle of the grpc.Server.
|
|
type Handler struct {
|
|
srv *grpc.Server
|
|
listener *chanListener
|
|
}
|
|
|
|
// Handle the connection by sending it to a channel for the grpc.Server to receive.
|
|
func (h *Handler) Handle(conn net.Conn) {
|
|
h.listener.conns <- conn
|
|
}
|
|
|
|
func (h *Handler) Run() error {
|
|
return h.srv.Serve(h.listener)
|
|
}
|
|
|
|
func (h *Handler) Shutdown() error {
|
|
h.srv.Stop()
|
|
return nil
|
|
}
|
|
|
|
// chanListener implements net.Listener for grpc.Server.
|
|
type chanListener struct {
|
|
conns chan net.Conn
|
|
addr net.Addr
|
|
done chan struct{}
|
|
}
|
|
|
|
// Accept blocks until a connection is received from Handle, and then returns the
|
|
// connection. Accept implements part of the net.Listener interface for grpc.Server.
|
|
func (l *chanListener) Accept() (net.Conn, error) {
|
|
select {
|
|
case c := <-l.conns:
|
|
return c, nil
|
|
case <-l.done:
|
|
return nil, &net.OpError{
|
|
Op: "accept",
|
|
Net: l.addr.Network(),
|
|
Addr: l.addr,
|
|
Err: fmt.Errorf("listener closed"),
|
|
}
|
|
}
|
|
}
|
|
|
|
func (l *chanListener) Addr() net.Addr {
|
|
return l.addr
|
|
}
|
|
|
|
func (l *chanListener) Close() error {
|
|
close(l.done)
|
|
return nil
|
|
}
|
|
|
|
// NoOpHandler implements the same methods as Handler, but performs no handling.
|
|
// It may be used in place of Handler to disable the grpc server.
|
|
type NoOpHandler struct {
|
|
Logger Logger
|
|
}
|
|
|
|
type Logger interface {
|
|
Error(string, ...interface{})
|
|
}
|
|
|
|
func (h NoOpHandler) Handle(conn net.Conn) {
|
|
h.Logger.Error("gRPC conn opened but gRPC RPC is disabled, closing",
|
|
"conn", logConn(conn))
|
|
_ = conn.Close()
|
|
}
|
|
|
|
func (h NoOpHandler) Run() error {
|
|
return nil
|
|
}
|
|
|
|
func (h NoOpHandler) Shutdown() error {
|
|
return nil
|
|
}
|
|
|
|
// logConn is a local copy of github.com/hashicorp/memberlist.LogConn, to avoid
|
|
// a large dependency for a minor formatting function.
|
|
// logConn is used to keep log formatting consistent.
|
|
func logConn(conn net.Conn) string {
|
|
if conn == nil {
|
|
return "from=<unknown address>"
|
|
}
|
|
addr := conn.RemoteAddr()
|
|
if addr == nil {
|
|
return "from=<unknown address>"
|
|
}
|
|
|
|
return fmt.Sprintf("from=%s", addr.String())
|
|
}
|