feat: allow customization of proxy transport configuration

go.mod

@@ -3,13 +3,14 @@ module forge.cadoles.com/cadoles/bouncer
 go 1.20
 
 require (
-	forge.cadoles.com/Cadoles/go-proxy v0.0.0-20230512083245-e2dc3e1a0333
+	forge.cadoles.com/Cadoles/go-proxy v0.0.0-20230701194111-c6b3d482cca6
 	github.com/Masterminds/sprig/v3 v3.2.3
 	github.com/btcsuite/btcd/btcutil v1.1.3
 	github.com/go-chi/chi/v5 v5.0.8
 	github.com/jedib0t/go-pretty/v6 v6.4.6
 	github.com/mitchellh/mapstructure v1.4.1
 	github.com/ory/dockertest/v3 v3.10.0
+	github.com/prometheus/client_golang v1.16.0
 	github.com/qri-io/jsonschema v0.2.1
 	github.com/redis/go-redis/v9 v9.0.4
 )
@@ -32,11 +33,10 @@ require (
 	github.com/docker/go-units v0.4.0 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/protobuf v1.5.3 // indirect
-	github.com/google/go-cmp v0.5.9 // indirect
 	github.com/google/shlex v0.0.0-20191202100458-e7afc7fbc510 // indirect
 	github.com/huandu/xstrings v1.3.3 // indirect
 	github.com/imdario/mergo v0.3.12 // indirect
-	github.com/kr/pretty v0.3.1 // indirect
+	github.com/kr/text v0.2.0 // indirect
 	github.com/mattn/go-runewidth v0.0.13 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
 	github.com/mitchellh/copystructure v1.0.0 // indirect
@@ -45,7 +45,6 @@ require (
 	github.com/opencontainers/go-digest v1.0.0 // indirect
 	github.com/opencontainers/image-spec v1.0.2 // indirect
 	github.com/opencontainers/runc v1.1.5 // indirect
-	github.com/prometheus/client_golang v1.16.0 // indirect
 	github.com/prometheus/client_model v0.3.0 // indirect
 	github.com/prometheus/common v0.42.0 // indirect
 	github.com/prometheus/procfs v0.10.1 // indirect
@@ -60,7 +59,6 @@ require (
 	github.com/xeipuuv/gojsonschema v1.2.0 // indirect
 	google.golang.org/genproto v0.0.0-20220314164441-57ef72a4c106 // indirect
 	google.golang.org/protobuf v1.30.0 // indirect
-	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 )
 

go.sum

@@ -49,8 +49,8 @@ cloud.google.com/go/storage v1.6.0/go.mod h1:N7U0C8pVQ/+NIKOBQyamJIeKQKkZ+mxpohl
 cloud.google.com/go/storage v1.8.0/go.mod h1:Wv1Oy7z6Yz3DshWRJFhqM/UCfaWIRTdp0RXyy7KQOVs=
 cloud.google.com/go/storage v1.10.0/go.mod h1:FLPqc6j+Ki4BU591ie1oL6qBQGu2Bl/tZ9ullr3+Kg0=
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
-forge.cadoles.com/Cadoles/go-proxy v0.0.0-20230512083245-e2dc3e1a0333 h1:dAajr9wX8WuFPrwjbKNXRmbF+4AaAT7bUj66G7gdZ+c=
+forge.cadoles.com/Cadoles/go-proxy v0.0.0-20230701194111-c6b3d482cca6 h1:FTk0ZoaV5N8Tkps5Da5RrDMZZXSHZIuD67Hy1Y4fsos=
-forge.cadoles.com/Cadoles/go-proxy v0.0.0-20230512083245-e2dc3e1a0333/go.mod h1:o8ZK5v/3J1dRmklFVn1l6WHAyQ3LgegyHjRIT8KLAFw=
+forge.cadoles.com/Cadoles/go-proxy v0.0.0-20230701194111-c6b3d482cca6/go.mod h1:o8ZK5v/3J1dRmklFVn1l6WHAyQ3LgegyHjRIT8KLAFw=
 github.com/Azure/go-ansiterm v0.0.0-20210617225240-d185dfc1b5a1 h1:UQHMgLO+TxOElx5B5HZ4hJQsoJ/PvUvKRhJHDQXO8P8=
 github.com/Azure/go-ansiterm v0.0.0-20210617225240-d185dfc1b5a1/go.mod h1:xomTg63KZ2rFqZQzSB4Vz2SUXa1BpHTVz9L5PTmPC4E=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
@@ -230,7 +230,6 @@ github.com/golang/protobuf v1.4.2/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw
 github.com/golang/protobuf v1.4.3/go.mod h1:oDoupMAO8OvCJWAcko0GGGIgR6R6ocIYbsSw735rRwI=
 github.com/golang/protobuf v1.5.0/go.mod h1:FsONVRAS9T7sI+LIUmWTfcYkHO4aIWwzhcaSAoJOfIk=
 github.com/golang/protobuf v1.5.1/go.mod h1:DopwsBzvsk0Fs44TXzsVbJyPhcCPeIwnvohx4u74HPM=
-github.com/golang/protobuf v1.5.2 h1:ROPKBNFfQgOUMifHyP+KYbvpjbdoFNs+aK7DXlji0Tw=
 github.com/golang/protobuf v1.5.2/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
 github.com/golang/protobuf v1.5.3 h1:KhyjKVUg7Usr/dYsdSqoFveMYd5ko72D+zANwlG1mmg=
 github.com/golang/protobuf v1.5.3/go.mod h1:XVQd3VNwM+JqD3oG2Ue2ip4fOMUkwXdXDdiuN0vRsmY=
@@ -252,7 +251,6 @@ github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
-github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXiIaQGbYVAs8BPL6v8lEs=
 github.com/google/martian/v3 v3.0.0/go.mod h1:y5Zk1BBys9G+gd6Jrk0W3cC1+ELVxBWuIGO+w/tUAp0=
 github.com/google/martian/v3 v3.1.0/go.mod h1:y5Zk1BBys9G+gd6Jrk0W3cC1+ELVxBWuIGO+w/tUAp0=
@@ -311,9 +309,7 @@ github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+o
 github.com/kkdai/bstream v0.0.0-20161212061736-f391b8402d23/go.mod h1:J+Gs4SYgM6CZQHDETBtE9HaSEkGmuNXF86RwHhHUvq4=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
-github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
+github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
-github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
-github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
@@ -386,7 +382,6 @@ github.com/opencontainers/selinux v1.10.0/go.mod h1:2i0OySw99QjzBBQByd1Gr9gSjvuh
 github.com/ory/dockertest/v3 v3.10.0 h1:4K3z2VMe8Woe++invjaTB7VRyQXQy5UY+loujO4aNE4=
 github.com/ory/dockertest/v3 v3.10.0/go.mod h1:nr57ZbRWMqfsdGdFNLHz5jjNdDb7VVFnzAeW1n5N1Lg=
 github.com/oxtoacart/bpool v0.0.0-20190530202638-03653db5a59c/go.mod h1:X07ZCGwUbLaax7L0S3Tw4hpejzu63ZrrQiUe6W0hcy0=
-github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
@@ -413,8 +408,6 @@ github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
-github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
-github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
@@ -607,8 +600,8 @@ golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.1.0 h1:wsuoTGHzEhffawBOhz5CYhcrV4IdKZbEyZjBMuTp12o=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.2.0 h1:PUR+T4wwASmuSTYdKjYHI5TD22Wy5ogLU5qZCOLxBrI=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181128092732-4ed8d59d0b35/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -680,8 +673,6 @@ golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.7.0 h1:3jlCCIQZPdOYu1h8BkNvLz8Kgwtae2cagcG/VamtZRU=
-golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=
 golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
@@ -908,14 +899,12 @@ google.golang.org/protobuf v1.24.0/go.mod h1:r/3tXBNzIEhYS9I1OUVjXDlt8tc493IdKGj
 google.golang.org/protobuf v1.25.0/go.mod h1:9JNX74DMeImyA3h4bdi1ymwjUzf21/xIlbajtzgsN7c=
 google.golang.org/protobuf v1.26.0-rc.1/go.mod h1:jlhhOSvTdKEhbULTjvd4ARK9grFBp09yW+WbY/TyQbw=
 google.golang.org/protobuf v1.26.0/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
-google.golang.org/protobuf v1.27.1 h1:SnqbnDw1V7RiZcXPx5MEeqPv2s79L9i7BJUlG/+RurQ=
 google.golang.org/protobuf v1.27.1/go.mod h1:9q0QmTI4eRPtz6boOQmLYwt+qCgq0jsYwAQnmE0givc=
 google.golang.org/protobuf v1.30.0 h1:kPPoIgf3TsEvrm0PFe15JQ+570QVxYzEvvHqChK+cng=
 google.golang.org/protobuf v1.30.0/go.mod h1:HV8QOd/L58Z+nl8r43ehVNZIU/HEI6OcFqwMG9pJV4I=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
 gopkg.in/fsnotify.v1 v1.4.7/go.mod h1:Tz8NjZHkW78fSQdbUxIjBTcgA1z1m8ZHf0WmKUhAMys=
 gopkg.in/go-playground/assert.v1 v1.2.1 h1:xoYuJVE7KT85PYWrN730RguIQO0ePzVRfFMXadIrXTM=

internal/config/proxy_server.go

@@ -1,13 +1,71 @@
 package config
 
+import "time"
+
 type ProxyServerConfig struct {
 	HTTP      HTTPConfig      `yaml:"http"`
 	Metrics   MetricsConfig   `yaml:"metrics"`
+	Transport TransportConfig `yaml:"transport"`
+	Dial      DialConfig      `yaml:"dial"`
+}
+
+// See https://pkg.go.dev/net/http#Transport
+type TransportConfig struct {
+	ForceAttemptHTTP2      InterpolatedBool      `yaml:"forceAttemptHTTP2"`
+	MaxIdleConns           InterpolatedInt       `yaml:"maxIdleConns"`
+	MaxIdleConnsPerHost    InterpolatedInt       `yaml:"maxIdleConnsPerHost"`
+	MaxConnsPerHost        InterpolatedInt       `yaml:"maxConnsPerHost"`
+	IdleConnTimeout        *InterpolatedDuration `yaml:"idleConnTimeout"`
+	TLSHandshakeTimeout    *InterpolatedDuration `yaml:"tlsHandshakeTimeout"`
+	ExpectContinueTimeout  *InterpolatedDuration `yaml:"expectContinueTimeout"`
+	DisableKeepAlives      InterpolatedBool      `yaml:"disableKeepAlives"`
+	DisableCompression     InterpolatedBool      `yaml:"disableCompression"`
+	ResponseHeaderTimeout  *InterpolatedDuration `yaml:"responseHeaderTimeout"`
+	WriteBufferSize        InterpolatedInt       `yaml:"writeBufferSize"`
+	ReadBufferSize         InterpolatedInt       `yaml:"readBufferSize"`
+	MaxResponseHeaderBytes InterpolatedInt       `yaml:"maxResponseHeaderBytes"`
 }
 
 func NewDefaultProxyServerConfig() ProxyServerConfig {
 	return ProxyServerConfig{
 		HTTP:      NewHTTPConfig("0.0.0.0", 8080),
 		Metrics:   NewDefaultMetricsConfig(),
+		Transport: NewDefaultTransportConfig(),
+		Dial:      NewDefaultDialConfig(),
+	}
+}
+
+// See https://pkg.go.dev/net#Dialer
+type DialConfig struct {
+	Timeout       *InterpolatedDuration `yaml:"timeout"`
+	KeepAlive     *InterpolatedDuration `yaml:"keepAlive"`
+	FallbackDelay *InterpolatedDuration `yaml:"fallbackDelay"`
+	DualStack     InterpolatedBool      `yaml:"dualStack"`
+}
+
+func NewDefaultDialConfig() DialConfig {
+	return DialConfig{
+		Timeout:       NewInterpolatedDuration(30 * time.Second),
+		KeepAlive:     NewInterpolatedDuration(30 * time.Second),
+		FallbackDelay: NewInterpolatedDuration(300 * time.Millisecond),
+		DualStack:     true,
+	}
+}
+
+func NewDefaultTransportConfig() TransportConfig {
+	return TransportConfig{
+		ForceAttemptHTTP2:      true,
+		MaxIdleConns:           100,
+		MaxIdleConnsPerHost:    100,
+		MaxConnsPerHost:        100,
+		IdleConnTimeout:        NewInterpolatedDuration(90 * time.Second),
+		TLSHandshakeTimeout:    NewInterpolatedDuration(10 * time.Second),
+		ExpectContinueTimeout:  NewInterpolatedDuration(1 * time.Second),
+		ResponseHeaderTimeout:  NewInterpolatedDuration(10 * time.Second),
+		DisableCompression:     false,
+		DisableKeepAlives:      false,
+		ReadBufferSize:         4096,
+		WriteBufferSize:        4096,
+		MaxResponseHeaderBytes: 0,
 	}
 }

internal/proxy/server.go

@@ -6,6 +6,9 @@ import (
 	"log"
 	"net"
 	"net/http"
+	"net/http/httputil"
+	"net/url"
+	"time"
 
 	"forge.cadoles.com/Cadoles/go-proxy"
 	bouncerChi "forge.cadoles.com/cadoles/bouncer/internal/chi"
@@ -115,6 +118,7 @@ func (s *Server) run(parentCtx context.Context, addrs chan net.Addr, errs chan e
 			proxy.WithResponseTransformers(
 				director.ResponseTransformer(),
 			),
+			proxy.WithReverseProxyFactory(s.createReverseProxy),
 		)
 
 		r.Handle("/*", handler)
@@ -127,6 +131,49 @@ func (s *Server) run(parentCtx context.Context, addrs chan net.Addr, errs chan e
 	logger.Info(ctx, "http server exiting")
 }
 
+func (s *Server) createReverseProxy(ctx context.Context, target *url.URL) *httputil.ReverseProxy {
+	reverseProxy := httputil.NewSingleHostReverseProxy(target)
+
+	dialConfig := s.serverConfig.Dial
+
+	dialer := &net.Dialer{
+		Timeout:       time.Duration(*dialConfig.Timeout),
+		KeepAlive:     time.Duration(*dialConfig.KeepAlive),
+		FallbackDelay: time.Duration(*dialConfig.FallbackDelay),
+		DualStack:     bool(dialConfig.DualStack),
+	}
+
+	transportConfig := s.serverConfig.Transport
+
+	reverseProxy.Transport = &http.Transport{
+		Proxy:                  http.ProxyFromEnvironment,
+		DialContext:            dialer.DialContext,
+		ForceAttemptHTTP2:      bool(transportConfig.ForceAttemptHTTP2),
+		MaxIdleConns:           int(transportConfig.MaxIdleConns),
+		MaxIdleConnsPerHost:    int(transportConfig.MaxIdleConnsPerHost),
+		MaxConnsPerHost:        int(transportConfig.MaxConnsPerHost),
+		IdleConnTimeout:        time.Duration(*transportConfig.IdleConnTimeout),
+		TLSHandshakeTimeout:    time.Duration(*transportConfig.TLSHandshakeTimeout),
+		ExpectContinueTimeout:  time.Duration(*transportConfig.ExpectContinueTimeout),
+		DisableKeepAlives:      bool(transportConfig.DisableKeepAlives),
+		DisableCompression:     bool(transportConfig.DisableCompression),
+		ResponseHeaderTimeout:  time.Duration(*transportConfig.ResponseHeaderTimeout),
+		WriteBufferSize:        int(transportConfig.WriteBufferSize),
+		ReadBufferSize:         int(transportConfig.ReadBufferSize),
+		MaxResponseHeaderBytes: int64(transportConfig.MaxResponseHeaderBytes),
+	}
+
+	reverseProxy.ErrorHandler = s.errorHandler
+
+	return reverseProxy
+}
+
+func (s *Server) errorHandler(w http.ResponseWriter, r *http.Request, err error) {
+	logger.Error(r.Context(), "proxy error", logger.E(errors.WithStack(err)))
+
+	http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
+}
+
 func NewServer(funcs ...OptionFunc) *Server {
 	opt := defaultOption()
 	for _, fn := range funcs {