cmd/gomote: add gomote rdp subcommand to open an RDP proxy to a Windows buildlet
Fixes golang/go#26090
Change-Id: Ib58fb7767384778b67d0d62d34c1132d70d75c23
Reviewed-on: https://go-review.googlesource.com/c/build/+/207378
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
diff --git a/buildlet/buildletclient.go b/buildlet/buildletclient.go
index ea7f56b..3c51e08 100644
--- a/buildlet/buildletclient.go
+++ b/buildlet/buildletclient.go
@@ -188,7 +188,7 @@
// RemoteName returns the name of this client's buildlet on the
// coordinator. If this buildlet isn't a remote buildlet created via
-// a buildlet, this returns the empty string.
+// gomote, this returns the empty string.
func (c *Client) RemoteName() string {
return c.remoteBuildlet
}
@@ -258,6 +258,37 @@
return c.httpClient.Do(req)
}
+// ProxyTCP connects to the given port on the remote buildlet.
+// The buildlet client must currently be a gomote client (RemoteName != "")
+// and the target type must be a VM type running on GCE. This was primarily
+// created for RDP to Windows machines, but it might get reused for other
+// purposes in the future.
+func (c *Client) ProxyTCP(port int) (io.ReadWriteCloser, error) {
+ if c.RemoteName() == "" {
+ return nil, errors.New("ProxyTCP currently only supports gomote-created buildlets")
+ }
+ req, err := http.NewRequest("POST", c.URL()+"/tcpproxy", nil)
+ if err != nil {
+ return nil, err
+ }
+ req.Header.Add("X-Target-Port", fmt.Sprint(port))
+ res, err := c.do(req)
+ if err != nil {
+ return nil, err
+ }
+ if res.StatusCode != http.StatusSwitchingProtocols {
+ slurp, _ := ioutil.ReadAll(io.LimitReader(res.Body, 4<<10))
+ res.Body.Close()
+ return nil, fmt.Errorf("wanted 101 Switching Protocols; unexpected response: %v, %q", res.Status, slurp)
+ }
+ rwc, ok := res.Body.(io.ReadWriteCloser)
+ if !ok {
+ res.Body.Close()
+ return nil, fmt.Errorf("tcpproxy response was not a Writer")
+ }
+ return rwc, nil
+}
+
// ProxyRoundTripper returns a RoundTripper that sends HTTP requests directly
// through to the underlying buildlet, adding auth and X-Buildlet-Proxy headers
// as necessary. This is really only intended for use by the coordinator.
diff --git a/cmd/gomote/gomote.go b/cmd/gomote/gomote.go
index 7114eb0..87ec0ca 100644
--- a/cmd/gomote/gomote.go
+++ b/cmd/gomote/gomote.go
@@ -34,6 +34,7 @@
put14 put Go 1.4 in place
puttar extract a tar.gz to a buildlet
rm delete files or directories
+ rdp RDP (Remote Desktop Protocol) to a Windows buildlet
run run a command on a buildlet
ssh ssh to a buildlet
@@ -149,6 +150,7 @@
registerCommand("put", "put files on a buildlet", put)
registerCommand("put14", "put Go 1.4 in place", put14)
registerCommand("puttar", "extract a tar.gz to a buildlet", putTar)
+ registerCommand("rdp", "RDP (Remote Desktop Protocol) to a Windows buildlet", rdp)
registerCommand("rm", "delete files or directories", rm)
registerCommand("run", "run a command on a buildlet", run)
registerCommand("ssh", "ssh to a buildlet", ssh)
diff --git a/cmd/gomote/rdp.go b/cmd/gomote/rdp.go
new file mode 100644
index 0000000..4ecae62
--- /dev/null
+++ b/cmd/gomote/rdp.go
@@ -0,0 +1,88 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+ "context"
+ "errors"
+ "flag"
+ "fmt"
+ "io"
+ "log"
+ "net"
+ "os"
+
+ "golang.org/x/build/buildlet"
+ "golang.org/x/sync/errgroup"
+)
+
+const rdpPort = 3389
+
+func rdp(args []string) error {
+ fs := flag.NewFlagSet("rdp", flag.ContinueOnError)
+ fs.Usage = func() {
+ fmt.Fprintln(os.Stderr, "rdp usage: gomote rdp [--listen=...] <instance>")
+ fs.PrintDefaults()
+ os.Exit(1)
+ }
+ var listen string
+ fs.StringVar(&listen, "listen", "localhost:"+fmt.Sprint(rdpPort), "local address to listen on")
+ fs.Parse(args)
+ if fs.NArg() != 1 {
+ fs.Usage()
+ }
+ name := fs.Arg(0)
+ bc, err := remoteClient(name)
+ if err != nil {
+ return err
+ }
+
+ ln, err := net.Listen("tcp", listen)
+ if err != nil {
+ return err
+ }
+ log.Printf("Listening on %v to proxy RDP.", ln.Addr())
+ for {
+ c, err := ln.Accept()
+ if err != nil {
+ return err
+ }
+ go handleRDPConn(bc, c)
+ }
+}
+
+func handleRDPConn(bc *buildlet.Client, c net.Conn) {
+ const Lmsgprefix = 64 // new in Go 1.14, harmless before
+ log := log.New(os.Stderr, c.RemoteAddr().String()+": ", log.LstdFlags|Lmsgprefix)
+ log.Printf("accepted connection, dialing buildlet via coordinator proxy...")
+ rwc, err := bc.ProxyTCP(rdpPort)
+ if err != nil {
+ c.Close()
+ log.Printf("failed to connect to buildlet via coordinator: %v", err)
+ return
+ }
+
+ log.Printf("connected to buildlet; proxying data.")
+
+ grp, ctx := errgroup.WithContext(context.Background())
+ grp.Go(func() error {
+ _, err := io.Copy(rwc, c)
+ if err == nil {
+ return errors.New("local client closed")
+ }
+ return fmt.Errorf("error copying from local to remote: %v", err)
+ })
+ grp.Go(func() error {
+ _, err := io.Copy(c, rwc)
+ if err == nil {
+ return errors.New("remote server closed")
+ }
+ return fmt.Errorf("error copying from remote to local: %v", err)
+ })
+ <-ctx.Done()
+ rwc.Close()
+ c.Close()
+ log.Printf("closing RDP connection: %v", grp.Wait())
+}
