Add file-server and reverse-proxy subcommands

modules/caddyhttp/reverseproxy/command.go

@@ -0,0 +1,138 @@
+// 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"
+	"log"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"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/mholt/certmagic"
+)
+
+func init() {
+	caddycmd.RegisterCommand(caddycmd.Command{
+		Name:  "reverse-proxy",
+		Func:  cmdReverseProxy,
+		Usage: "[--from <addr>] [--to <addr>]",
+		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 traffic from the --from address to the --to address.
+
+If the --from address has a domain name, Caddy will attempt to serve the
+proxy over HTTPS with a certificate.
+`,
+		Flags: func() *flag.FlagSet {
+			fs := flag.NewFlagSet("file-server", flag.ExitOnError)
+			fs.String("from", "", "Address to receive traffic on")
+			fs.String("to", "", "Upstream address to proxy traffic to")
+			return fs
+		}(),
+	})
+}
+
+func cmdReverseProxy(fs caddycmd.Flags) (int, error) {
+	from := fs.String("from")
+	to := fs.String("to")
+
+	if from == "" {
+		from = "localhost:" + httpcaddyfile.DefaultPort
+	}
+
+	if !strings.Contains(from, "://") {
+		from = "http://" + from
+	}
+
+	fromURL, err := url.Parse(from)
+	if err != nil {
+		fromURL.Host = from
+	}
+
+	toURL, err := url.Parse(to)
+	if err != nil {
+		toURL.Host = to
+	}
+
+	ht := HTTPTransport{}
+	if toURL.Scheme == "https" {
+		ht.TLS = new(TLSConfig)
+	}
+
+	handler := Handler{
+		TransportRaw: caddyconfig.JSONModuleObject(ht, "protocol", "http", nil),
+		Upstreams:    UpstreamPool{{Dial: toURL.Host}},
+		Headers: &headers.Handler{
+			Request: &headers.HeaderOps{
+				Set: http.Header{
+					"Host": []string{"{http.handlers.reverse_proxy.upstream.host}"},
+				},
+			},
+		},
+	}
+
+	route := caddyhttp.Route{
+		HandlersRaw: []json.RawMessage{
+			caddyconfig.JSONModuleObject(handler, "handler", "reverse_proxy", nil),
+		},
+	}
+	if fromURL.Hostname() != "" {
+		route.MatcherSetsRaw = []map[string]json.RawMessage{
+			map[string]json.RawMessage{
+				"host": caddyconfig.JSON(caddyhttp.MatchHost{fromURL.Hostname()}, nil),
+			},
+		}
+	}
+
+	listen := ":" + httpcaddyfile.DefaultPort
+	if certmagic.HostQualifies(fromURL.Hostname()) {
+		listen = ":443"
+	}
+
+	server := &caddyhttp.Server{
+		Routes: caddyhttp.RouteList{route},
+		Listen: []string{listen},
+	}
+
+	httpApp := caddyhttp.App{
+		Servers: map[string]*caddyhttp.Server{"proxy": server},
+	}
+
+	cfg := &caddy.Config{
+		AppsRaw: map[string]json.RawMessage{
+			"http": caddyconfig.JSON(httpApp, nil),
+		},
+	}
+
+	err = caddy.Run(cfg)
+	if err != nil {
+		return caddy.ExitCodeFailedStartup, err
+	}
+
+	log.Printf("Caddy 2 proxying from %s to %s", from, to)
+
+	select {}
+}