consul/agent/grpc-external/server.go

120 lines
4.1 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package external
import (
"context"
"fmt"
"strings"
"time"
"github.com/armon/go-metrics"
middleware "github.com/grpc-ecosystem/go-grpc-middleware"
recovery "github.com/grpc-ecosystem/go-grpc-middleware/recovery"
"github.com/hashi-derek/grpc-proxy/proxy"
"github.com/hashicorp/go-hclog"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/credentials"
"google.golang.org/grpc/keepalive"
"google.golang.org/grpc/metadata"
"google.golang.org/grpc/status"
"github.com/hashicorp/consul/agent/consul/rate"
agentmiddleware "github.com/hashicorp/consul/agent/grpc-middleware"
"github.com/hashicorp/consul/tlsutil"
)
const FORWARD_SERVICE_NAME_PREFIX = "/hashicorp.consul."
var (
metricsLabels = []metrics.Label{{
Name: "server_type",
Value: "external",
}}
)
// NewServer constructs a gRPC server for the external gRPC port, to which
// handlers can be registered.
func NewServer(
logger hclog.Logger,
metricsObj *metrics.Metrics,
tls *tlsutil.Configurator,
limiter rate.RequestLimitsHandler,
keepaliveParams keepalive.ServerParameters,
serverConn *grpc.ClientConn,
) *grpc.Server {
if metricsObj == nil {
metricsObj = metrics.Default()
}
recoveryOpts := agentmiddleware.PanicHandlerMiddlewareOpts(logger)
unaryInterceptors := []grpc.UnaryServerInterceptor{
// Add middlware interceptors to recover in case of panics.
recovery.UnaryServerInterceptor(recoveryOpts...),
}
streamInterceptors := []grpc.StreamServerInterceptor{
// Add middlware interceptors to recover in case of panics.
recovery.StreamServerInterceptor(recoveryOpts...),
agentmiddleware.NewActiveStreamCounter(metricsObj, metricsLabels).Intercept,
}
if tls != nil {
// Attach TLS middleware if TLS is provided.
authInterceptor := agentmiddleware.AuthInterceptor{TLS: tls, Logger: logger}
unaryInterceptors = append(unaryInterceptors, authInterceptor.InterceptUnary)
streamInterceptors = append(streamInterceptors, authInterceptor.InterceptStream)
}
opts := []grpc.ServerOption{
grpc.MaxConcurrentStreams(2048),
grpc.MaxRecvMsgSize(50 * 1024 * 1024),
grpc.InTapHandle(agentmiddleware.ServerRateLimiterMiddleware(limiter, agentmiddleware.NewPanicHandler(logger), logger)),
grpc.StatsHandler(agentmiddleware.NewStatsHandler(metricsObj, metricsLabels)),
middleware.WithUnaryServerChain(unaryInterceptors...),
middleware.WithStreamServerChain(streamInterceptors...),
grpc.KeepaliveParams(keepaliveParams),
grpc.KeepaliveEnforcementPolicy(keepalive.EnforcementPolicy{
// This must be less than the keealive.ClientParameters Time setting, otherwise
// the server will disconnect the client for sending too many keepalive pings.
// Currently the client param is set to 30s.
MinTime: 15 * time.Second,
}),
}
// forward FORWARD_SERVICE_NAME_PREFIX services from client agent to server agent
if serverConn != nil {
opts = append(opts, grpc.UnknownServiceHandler(proxy.TransparentHandler(makeDirector(serverConn, logger))))
}
if tls != nil {
// Attach TLS credentials, if provided.
tlsCreds := agentmiddleware.NewOptionalTransportCredentials(
credentials.NewTLS(tls.IncomingGRPCConfig()),
logger)
opts = append(opts, grpc.Creds(tlsCreds))
}
return grpc.NewServer(opts...)
}
func makeDirector(serverConn *grpc.ClientConn, logger hclog.Logger) func(ctx context.Context, fullMethodName string) (context.Context, *grpc.ClientConn, error) {
return func(ctx context.Context, fullMethodName string) (context.Context, *grpc.ClientConn, error) {
var mdCopy metadata.MD
md, ok := metadata.FromIncomingContext(ctx)
if !ok {
mdCopy = metadata.MD{}
} else {
mdCopy = md.Copy()
}
outCtx := metadata.NewOutgoingContext(ctx, mdCopy)
logger.Debug("forwarding the request to the consul server", "method", fullMethodName)
// throw unimplemented error if the method is not meant to be forwarded
if !strings.HasPrefix(fullMethodName, FORWARD_SERVICE_NAME_PREFIX) {
return outCtx, nil, status.Errorf(codes.Unimplemented, fmt.Sprintf("Unknown method %s", fullMethodName))
}
return outCtx, serverConn, nil
}
}