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
|
// 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 (
"encoding/json"
"flag"
"fmt"
"net/http"
"strconv"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/caddyconfig"
"github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile"
caddycmd "github.com/caddyserver/caddy/v2/cmd"
"github.com/caddyserver/caddy/v2/modules/caddyhttp"
"github.com/caddyserver/caddy/v2/modules/caddyhttp/headers"
"github.com/caddyserver/caddy/v2/modules/caddytls"
)
func init() {
caddycmd.RegisterCommand(caddycmd.Command{
Name: "reverse-proxy",
Func: cmdReverseProxy,
Usage: "[--from <addr>] [--to <addr>] [--change-host-header]",
Short: "A quick and production-ready reverse proxy",
Long: `
A simple but production-ready reverse proxy. Useful for quick deployments,
demos, and development.
Simply shuttles HTTP(S) traffic from the --from address to the --to address.
Unless otherwise specified in the addresses, the --from address will be
assumed to be HTTPS if a hostname is given, and the --to address will be
assumed to be HTTP.
If the --from address has a host or IP, Caddy will attempt to serve the
proxy over HTTPS with a certificate (unless overridden by the HTTP scheme
or port).
If --change-host-header is set, the Host header on the request will be modified
from its original incoming value to the address of the upstream. (Otherwise, by
default, all incoming headers are passed through unmodified.)
`,
Flags: func() *flag.FlagSet {
fs := flag.NewFlagSet("reverse-proxy", flag.ExitOnError)
fs.String("from", "localhost", "Address on which to receive traffic")
fs.String("to", "", "Upstream address to which traffic should be sent")
fs.Bool("change-host-header", false, "Set upstream Host header to address of upstream")
fs.Bool("insecure", false, "Disable TLS verification (WARNING: DISABLES SECURITY BY NOT VERIFYING SSL CERTIFICATES!)")
fs.Bool("internal-certs", false, "Use internal CA for issuing certs")
return fs
}(),
})
}
func cmdReverseProxy(fs caddycmd.Flags) (int, error) {
caddy.TrapSignals()
from := fs.String("from")
to := fs.String("to")
changeHost := fs.Bool("change-host-header")
insecure := fs.Bool("insecure")
internalCerts := fs.Bool("internal-certs")
httpPort := strconv.Itoa(caddyhttp.DefaultHTTPPort)
httpsPort := strconv.Itoa(caddyhttp.DefaultHTTPSPort)
if to == "" {
return caddy.ExitCodeFailedStartup, fmt.Errorf("--to is required")
}
// set up the downstream address; assume missing information from given parts
fromAddr, err := httpcaddyfile.ParseAddress(from)
if err != nil {
return caddy.ExitCodeFailedStartup, fmt.Errorf("invalid downstream address %s: %v", from, err)
}
if fromAddr.Path != "" {
return caddy.ExitCodeFailedStartup, fmt.Errorf("paths are not allowed: %s", from)
}
if fromAddr.Scheme == "" {
if fromAddr.Port == httpPort || fromAddr.Host == "" {
fromAddr.Scheme = "http"
} else {
fromAddr.Scheme = "https"
}
}
if fromAddr.Port == "" {
if fromAddr.Scheme == "http" {
fromAddr.Port = httpPort
} else if fromAddr.Scheme == "https" {
fromAddr.Port = httpsPort
}
}
// set up the upstream address; assume missing information from given parts
toAddr, toScheme, err := parseUpstreamDialAddress(to)
if err != nil {
return caddy.ExitCodeFailedStartup, fmt.Errorf("invalid upstream address %s: %v", to, err)
}
// proceed to build the handler and server
ht := HTTPTransport{}
if toScheme == "https" {
ht.TLS = new(TLSConfig)
if insecure {
ht.TLS.InsecureSkipVerify = true
}
}
handler := Handler{
TransportRaw: caddyconfig.JSONModuleObject(ht, "protocol", "http", nil),
Upstreams: UpstreamPool{{Dial: toAddr}},
}
if changeHost {
handler.Headers = &headers.Handler{
Request: &headers.HeaderOps{
Set: http.Header{
"Host": []string{"{http.reverse_proxy.upstream.hostport}"},
},
},
}
}
route := caddyhttp.Route{
HandlersRaw: []json.RawMessage{
caddyconfig.JSONModuleObject(handler, "handler", "reverse_proxy", nil),
},
}
if fromAddr.Host != "" {
route.MatcherSetsRaw = []caddy.ModuleMap{
{
"host": caddyconfig.JSON(caddyhttp.MatchHost{fromAddr.Host}, nil),
},
}
}
server := &caddyhttp.Server{
Routes: caddyhttp.RouteList{route},
Listen: []string{":" + fromAddr.Port},
}
httpApp := caddyhttp.App{
Servers: map[string]*caddyhttp.Server{"proxy": server},
}
appsRaw := caddy.ModuleMap{
"http": caddyconfig.JSON(httpApp, nil),
}
if internalCerts && fromAddr.Host != "" {
tlsApp := caddytls.TLS{
Automation: &caddytls.AutomationConfig{
Policies: []*caddytls.AutomationPolicy{{
Subjects: []string{fromAddr.Host},
IssuersRaw: []json.RawMessage{json.RawMessage(`{"module":"internal"}`)},
}},
},
}
appsRaw["tls"] = caddyconfig.JSON(tlsApp, nil)
}
cfg := &caddy.Config{
Admin: &caddy.AdminConfig{Disabled: true},
AppsRaw: appsRaw,
}
err = caddy.Run(cfg)
if err != nil {
return caddy.ExitCodeFailedStartup, err
}
fmt.Printf("Caddy proxying %s -> %s\n", fromAddr.String(), toAddr)
select {}
}
|
