open-consul/agent/grpc-internal/handler.go
Dan Upton 34140ff3e0
grpc: rename public/private directories to external/internal (#13721)
Previously, public referred to gRPC services that are both exposed on
the dedicated gRPC port and have their definitions in the proto-public
directory (so were considered usable by 3rd parties). Whereas private
referred to services on the multiplexed server port that are only usable
by agents and other servers.

Now, we're splitting these definitions, such that external/internal
refers to the port and public/private refers to whether they can be used
by 3rd parties.

This is necessary because the peering replication API needs to be
exposed on the dedicated port, but is not (yet) suitable for use by 3rd
parties.
2022-07-13 16:33:48 +01:00

142 lines
3.7 KiB
Go

package internal
import (
"fmt"
"net"
"time"
agentmiddleware "github.com/hashicorp/consul/agent/grpc-middleware"
middleware "github.com/grpc-ecosystem/go-grpc-middleware"
recovery "github.com/grpc-ecosystem/go-grpc-middleware/recovery"
"google.golang.org/grpc"
"google.golang.org/grpc/keepalive"
)
// 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(logger Logger, addr net.Addr, register func(server *grpc.Server)) *Handler {
metrics := defaultMetrics()
// We don't need to pass tls.Config to the server since it's multiplexed
// behind the RPC listener, which already has TLS configured.
recoveryOpts := agentmiddleware.PanicHandlerMiddlewareOpts(logger)
opts := []grpc.ServerOption{
grpc.StatsHandler(newStatsHandler(metrics)),
middleware.WithUnaryServerChain(
// Add middlware interceptors to recover in case of panics.
recovery.UnaryServerInterceptor(recoveryOpts...),
),
middleware.WithStreamServerChain(
// Add middlware interceptors to recover in case of panics.
recovery.StreamServerInterceptor(recoveryOpts...),
(&activeStreamCounter{metrics: metrics}).Intercept,
),
grpc.KeepaliveEnforcementPolicy(keepalive.EnforcementPolicy{
MinTime: 15 * time.Second,
}),
}
// 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(opts...)
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())
}