caddy/modules/caddyhttp/reverseproxy/command.go

320 lines
10 KiB
Go

// 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"
"fmt"
"net/http"
"strconv"
"strings"
"github.com/spf13/cobra"
"go.uber.org/zap"
caddycmd "github.com/caddyserver/caddy/v2/cmd"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/caddyconfig"
"github.com/caddyserver/caddy/v2/caddyconfig/httpcaddyfile"
"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",
Usage: `[--from <addr>] [--to <addr>] [--change-host-header] [--insecure] [--internal-certs] [--disable-redirects] [--header-up "Field: value"] [--header-down "Field: value"] [--access-log] [--debug]`,
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.
Multiple --to addresses may be specified by repeating the flag.
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 serving HTTPS:
--disable-redirects can be used to avoid binding to the HTTP port.
--internal-certs can be used to force issuance certs using the internal
CA instead of attempting to issue a public certificate.
For proxying:
--header-up can be used to set a request header to send to the upstream.
--header-down can be used to set a response header to send back to the client.
--change-host-header sets the Host header on the request to the address
of the upstream, instead of defaulting to the incoming Host header.
This is a shortcut for --header-up "Host: {http.reverse_proxy.upstream.hostport}".
--insecure disables TLS verification with the upstream. WARNING: THIS
DISABLES SECURITY BY NOT VERIFYING THE UPSTREAM'S CERTIFICATE.
`,
CobraFunc: func(cmd *cobra.Command) {
cmd.Flags().StringP("from", "f", "localhost", "Address on which to receive traffic")
cmd.Flags().StringSliceP("to", "t", []string{}, "Upstream address(es) to which traffic should be sent")
cmd.Flags().BoolP("change-host-header", "c", false, "Set upstream Host header to address of upstream")
cmd.Flags().BoolP("insecure", "", false, "Disable TLS verification (WARNING: DISABLES SECURITY BY NOT VERIFYING TLS CERTIFICATES!)")
cmd.Flags().BoolP("disable-redirects", "r", false, "Disable HTTP->HTTPS redirects")
cmd.Flags().BoolP("internal-certs", "i", false, "Use internal CA for issuing certs")
cmd.Flags().StringSliceP("header-up", "H", []string{}, "Set a request header to send to the upstream (format: \"Field: value\")")
cmd.Flags().StringSliceP("header-down", "d", []string{}, "Set a response header to send back to the client (format: \"Field: value\")")
cmd.Flags().BoolP("access-log", "", false, "Enable the access log")
cmd.Flags().BoolP("debug", "v", false, "Enable verbose debug logs")
cmd.RunE = caddycmd.WrapCommandFuncForCobra(cmdReverseProxy)
},
})
}
func cmdReverseProxy(fs caddycmd.Flags) (int, error) {
caddy.TrapSignals()
from := fs.String("from")
changeHost := fs.Bool("change-host-header")
insecure := fs.Bool("insecure")
disableRedir := fs.Bool("disable-redirects")
internalCerts := fs.Bool("internal-certs")
accessLog := fs.Bool("access-log")
debug := fs.Bool("debug")
httpPort := strconv.Itoa(caddyhttp.DefaultHTTPPort)
httpsPort := strconv.Itoa(caddyhttp.DefaultHTTPSPort)
to, err := fs.GetStringSlice("to")
if err != nil {
return caddy.ExitCodeFailedStartup, fmt.Errorf("invalid to flag: %v", err)
}
if len(to) == 0 {
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
// mixing schemes isn't supported, so use first defined (if available)
toAddresses := make([]string, len(to))
var toScheme string
for i, toLoc := range to {
addr, err := parseUpstreamDialAddress(toLoc)
if err != nil {
return caddy.ExitCodeFailedStartup, fmt.Errorf("invalid upstream address %s: %v", toLoc, err)
}
if addr.scheme != "" && toScheme == "" {
toScheme = addr.scheme
}
toAddresses[i] = addr.dialAddr()
}
// proceed to build the handler and server
ht := HTTPTransport{}
if toScheme == "https" {
ht.TLS = new(TLSConfig)
if insecure {
ht.TLS.InsecureSkipVerify = true
}
}
upstreamPool := UpstreamPool{}
for _, toAddr := range toAddresses {
parsedAddr, err := caddy.ParseNetworkAddress(toAddr)
if err != nil {
return caddy.ExitCodeFailedStartup, fmt.Errorf("invalid upstream address %s: %v", toAddr, err)
}
if parsedAddr.StartPort == 0 && parsedAddr.EndPort == 0 {
// unix networks don't have ports
upstreamPool = append(upstreamPool, &Upstream{
Dial: toAddr,
})
} else {
// expand a port range into multiple upstreams
for i := parsedAddr.StartPort; i <= parsedAddr.EndPort; i++ {
upstreamPool = append(upstreamPool, &Upstream{
Dial: caddy.JoinNetworkAddress("", parsedAddr.Host, fmt.Sprint(i)),
})
}
}
}
handler := Handler{
TransportRaw: caddyconfig.JSONModuleObject(ht, "protocol", "http", nil),
Upstreams: upstreamPool,
}
// set up header_up
headerUp, err := fs.GetStringSlice("header-up")
if err != nil {
return caddy.ExitCodeFailedStartup, fmt.Errorf("invalid header flag: %v", err)
}
if len(headerUp) > 0 {
reqHdr := make(http.Header)
for i, h := range headerUp {
key, val, found := strings.Cut(h, ":")
key, val = strings.TrimSpace(key), strings.TrimSpace(val)
if !found || key == "" || val == "" {
return caddy.ExitCodeFailedStartup, fmt.Errorf("header-up %d: invalid format \"%s\" (expecting \"Field: value\")", i, h)
}
reqHdr.Set(key, val)
}
handler.Headers = &headers.Handler{
Request: &headers.HeaderOps{
Set: reqHdr,
},
}
}
// set up header_down
headerDown, err := fs.GetStringSlice("header-down")
if err != nil {
return caddy.ExitCodeFailedStartup, fmt.Errorf("invalid header flag: %v", err)
}
if len(headerDown) > 0 {
respHdr := make(http.Header)
for i, h := range headerDown {
key, val, found := strings.Cut(h, ":")
key, val = strings.TrimSpace(key), strings.TrimSpace(val)
if !found || key == "" || val == "" {
return caddy.ExitCodeFailedStartup, fmt.Errorf("header-down %d: invalid format \"%s\" (expecting \"Field: value\")", i, h)
}
respHdr.Set(key, val)
}
if handler.Headers == nil {
handler.Headers = &headers.Handler{}
}
handler.Headers.Response = &headers.RespHeaderOps{
HeaderOps: &headers.HeaderOps{
Set: respHdr,
},
}
}
if changeHost {
if handler.Headers == nil {
handler.Headers = new(headers.Handler)
}
if handler.Headers.Request == nil {
handler.Headers.Request = new(headers.HeaderOps)
}
if handler.Headers.Request.Set == nil {
handler.Headers.Request.Set = http.Header{}
}
handler.Headers.Request.Set.Set("Host", "{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},
}
if accessLog {
server.Logs = &caddyhttp.ServerLogConfig{}
}
if fromAddr.Scheme == "http" {
server.AutoHTTPS = &caddyhttp.AutoHTTPSConfig{Disabled: true}
} else if disableRedir {
server.AutoHTTPS = &caddyhttp.AutoHTTPSConfig{DisableRedir: true}
}
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{{
SubjectsRaw: []string{fromAddr.Host},
IssuersRaw: []json.RawMessage{json.RawMessage(`{"module":"internal"}`)},
}},
},
}
appsRaw["tls"] = caddyconfig.JSON(tlsApp, nil)
}
var false bool
cfg := &caddy.Config{
Admin: &caddy.AdminConfig{
Disabled: true,
Config: &caddy.ConfigSettings{
Persist: &false,
},
},
AppsRaw: appsRaw,
}
if debug {
cfg.Logging = &caddy.Logging{
Logs: map[string]*caddy.CustomLog{
"default": {BaseLog: caddy.BaseLog{Level: zap.DebugLevel.CapitalString()}},
},
}
}
err = caddy.Run(cfg)
if err != nil {
return caddy.ExitCodeFailedStartup, err
}
caddy.Log().Info("caddy proxying", zap.String("from", fromAddr.String()), zap.Strings("to", toAddresses))
if len(toAddresses) > 1 {
caddy.Log().Info("using default load balancing policy", zap.String("policy", "random"))
}
select {}
}