open-consul/agent/grpc-internal/handler.go
2023-04-04 17:30:06 +01:00

127 lines
3.5 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
package internal
import (
"fmt"
"net"
"time"
"github.com/armon/go-metrics"
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"
"github.com/hashicorp/consul/agent/consul/rate"
)
var (
metricsLabels = []metrics.Label{{
Name: "server_type",
Value: "internal",
}}
)
// 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), metricsObj *metrics.Metrics, rateLimiter rate.RequestLimitsHandler) *Handler {
if metricsObj == nil {
metricsObj = metrics.Default()
}
// 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.InTapHandle(agentmiddleware.ServerRateLimiterMiddleware(rateLimiter, agentmiddleware.NewPanicHandler(logger), logger)),
grpc.StatsHandler(agentmiddleware.NewStatsHandler(metricsObj, metricsLabels)),
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...),
agentmiddleware.NewActiveStreamCounter(metricsObj, metricsLabels).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)
return &Handler{srv: srv, listener: NewListener(addr)}
}
// 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 *Listener
}
// 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
}
// 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{})
Warn(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())
}