1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
|
// Copyright 2015 Matthew Holt and The Caddy Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package reverseproxy
import (
"context"
"crypto/tls"
"crypto/x509"
"encoding/base64"
"fmt"
"net"
"net/http"
"reflect"
"time"
"github.com/caddyserver/caddy/v2"
)
func init() {
caddy.RegisterModule(HTTPTransport{})
}
// HTTPTransport is essentially a configuration wrapper for http.Transport.
// It defines a JSON structure useful when configuring the HTTP transport
// for Caddy's reverse proxy.
type HTTPTransport struct {
// TODO: It's possible that other transports (like fastcgi) might be
// able to borrow/use at least some of these config fields; if so,
// move them into a type called CommonTransport and embed it
TLS *TLSConfig `json:"tls,omitempty"`
KeepAlive *KeepAlive `json:"keep_alive,omitempty"`
Compression *bool `json:"compression,omitempty"`
MaxConnsPerHost int `json:"max_conns_per_host,omitempty"` // TODO: NOTE: we use our health check stuff to enforce max REQUESTS per host, but this is connections
DialTimeout caddy.Duration `json:"dial_timeout,omitempty"`
FallbackDelay caddy.Duration `json:"dial_fallback_delay,omitempty"`
ResponseHeaderTimeout caddy.Duration `json:"response_header_timeout,omitempty"`
ExpectContinueTimeout caddy.Duration `json:"expect_continue_timeout,omitempty"`
MaxResponseHeaderSize int64 `json:"max_response_header_size,omitempty"`
WriteBufferSize int `json:"write_buffer_size,omitempty"`
ReadBufferSize int `json:"read_buffer_size,omitempty"`
RoundTripper http.RoundTripper `json:"-"`
}
// CaddyModule returns the Caddy module information.
func (HTTPTransport) CaddyModule() caddy.ModuleInfo {
return caddy.ModuleInfo{
Name: "http.handlers.reverse_proxy.transport.http",
New: func() caddy.Module { return new(HTTPTransport) },
}
}
// Provision sets up h.RoundTripper with a http.Transport
// that is ready to use.
func (h *HTTPTransport) Provision(_ caddy.Context) error {
dialer := &net.Dialer{
Timeout: time.Duration(h.DialTimeout),
FallbackDelay: time.Duration(h.FallbackDelay),
// TODO: Resolver
}
rt := &http.Transport{
DialContext: func(ctx context.Context, network, address string) (net.Conn, error) {
// the proper dialing information should be embedded into the request's context
if dialInfoVal := ctx.Value(DialInfoCtxKey); dialInfoVal != nil {
dialInfo := dialInfoVal.(DialInfo)
network = dialInfo.Network
address = dialInfo.Address
}
return dialer.DialContext(ctx, network, address)
},
MaxConnsPerHost: h.MaxConnsPerHost,
ResponseHeaderTimeout: time.Duration(h.ResponseHeaderTimeout),
ExpectContinueTimeout: time.Duration(h.ExpectContinueTimeout),
MaxResponseHeaderBytes: h.MaxResponseHeaderSize,
WriteBufferSize: h.WriteBufferSize,
ReadBufferSize: h.ReadBufferSize,
}
if h.TLS != nil {
rt.TLSHandshakeTimeout = time.Duration(h.TLS.HandshakeTimeout)
var err error
rt.TLSClientConfig, err = h.TLS.MakeTLSClientConfig()
if err != nil {
return fmt.Errorf("making TLS client config: %v", err)
}
}
if h.KeepAlive != nil {
dialer.KeepAlive = time.Duration(h.KeepAlive.ProbeInterval)
if enabled := h.KeepAlive.Enabled; enabled != nil {
rt.DisableKeepAlives = !*enabled
}
rt.MaxIdleConns = h.KeepAlive.MaxIdleConns
rt.MaxIdleConnsPerHost = h.KeepAlive.MaxIdleConnsPerHost
rt.IdleConnTimeout = time.Duration(h.KeepAlive.IdleConnTimeout)
}
if h.Compression != nil {
rt.DisableCompression = !*h.Compression
}
h.RoundTripper = rt
return nil
}
// RoundTrip implements http.RoundTripper with h.RoundTripper.
func (h HTTPTransport) RoundTrip(req *http.Request) (*http.Response, error) {
return h.RoundTripper.RoundTrip(req)
}
// Cleanup implements caddy.CleanerUpper and closes any idle connections.
func (h HTTPTransport) Cleanup() error {
if ht, ok := h.RoundTripper.(*http.Transport); ok {
ht.CloseIdleConnections()
}
return nil
}
// TLSConfig holds configuration related to the
// TLS configuration for the transport/client.
type TLSConfig struct {
RootCAPool []string `json:"root_ca_pool,omitempty"`
// TODO: Should the client cert+key config use caddytls.CertificateLoader modules?
ClientCertificateFile string `json:"client_certificate_file,omitempty"`
ClientCertificateKeyFile string `json:"client_certificate_key_file,omitempty"`
InsecureSkipVerify bool `json:"insecure_skip_verify,omitempty"`
HandshakeTimeout caddy.Duration `json:"handshake_timeout,omitempty"`
}
// MakeTLSClientConfig returns a tls.Config usable by a client to a backend.
// If there is no custom TLS configuration, a nil config may be returned.
func (t TLSConfig) MakeTLSClientConfig() (*tls.Config, error) {
cfg := new(tls.Config)
// client auth
if t.ClientCertificateFile != "" && t.ClientCertificateKeyFile == "" {
return nil, fmt.Errorf("client_certificate_file specified without client_certificate_key_file")
}
if t.ClientCertificateFile == "" && t.ClientCertificateKeyFile != "" {
return nil, fmt.Errorf("client_certificate_key_file specified without client_certificate_file")
}
if t.ClientCertificateFile != "" && t.ClientCertificateKeyFile != "" {
cert, err := tls.LoadX509KeyPair(t.ClientCertificateFile, t.ClientCertificateKeyFile)
if err != nil {
return nil, fmt.Errorf("loading client certificate key pair: %v", err)
}
cfg.Certificates = []tls.Certificate{cert}
}
// trusted root CAs
if len(t.RootCAPool) > 0 {
rootPool := x509.NewCertPool()
for _, encodedCACert := range t.RootCAPool {
caCert, err := decodeBase64DERCert(encodedCACert)
if err != nil {
return nil, fmt.Errorf("parsing CA certificate: %v", err)
}
rootPool.AddCert(caCert)
}
cfg.RootCAs = rootPool
}
// throw all security out the window
cfg.InsecureSkipVerify = t.InsecureSkipVerify
// only return a config if it's not empty
if reflect.DeepEqual(cfg, new(tls.Config)) {
return nil, nil
}
cfg.NextProtos = []string{"h2", "http/1.1"} // TODO: ensure that this actually enables HTTP/2
return cfg, nil
}
// decodeBase64DERCert base64-decodes, then DER-decodes, certStr.
func decodeBase64DERCert(certStr string) (*x509.Certificate, error) {
// decode base64
derBytes, err := base64.StdEncoding.DecodeString(certStr)
if err != nil {
return nil, err
}
// parse the DER-encoded certificate
return x509.ParseCertificate(derBytes)
}
// KeepAlive holds configuration pertaining to HTTP Keep-Alive.
type KeepAlive struct {
Enabled *bool `json:"enabled,omitempty"`
ProbeInterval caddy.Duration `json:"probe_interval,omitempty"`
MaxIdleConns int `json:"max_idle_conns,omitempty"`
MaxIdleConnsPerHost int `json:"max_idle_conns_per_host,omitempty"`
IdleConnTimeout caddy.Duration `json:"idle_timeout,omitempty"` // how long should connections be kept alive when idle
}
// Interface guards
var (
_ caddy.Provisioner = (*HTTPTransport)(nil)
_ http.RoundTripper = (*HTTPTransport)(nil)
_ caddy.CleanerUpper = (*HTTPTransport)(nil)
)
|
