X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/4046a93e9f5b47771b10cd48c4357a452ed6dc6a..a42604972cccf8dd9c8341c260927a6c48c62b84:/cmd/arvados-client/container_gateway.go

diff --git a/cmd/arvados-client/container_gateway.go b/cmd/arvados-client/container_gateway.go
index a638000ae6..55f8c33bc7 100644
--- a/cmd/arvados-client/container_gateway.go
+++ b/cmd/arvados-client/container_gateway.go
@@ -5,6 +5,7 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"flag"
 	"fmt"
@@ -12,9 +13,11 @@ import (
 	"net/url"
 	"os"
 	"os/exec"
+	"path/filepath"
 	"strings"
 	"syscall"
 
+	"git.arvados.org/arvados.git/lib/cmd"
 	"git.arvados.org/arvados.git/lib/controller/rpc"
 	"git.arvados.org/arvados.git/sdk/go/arvados"
 )
@@ -25,25 +28,11 @@ type shellCommand struct{}
 
 func (shellCommand) RunCommand(prog string, args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	f := flag.NewFlagSet(prog, flag.ContinueOnError)
-	f.SetOutput(stderr)
-	f.Usage = func() {
-		fmt.Fprint(stderr, prog+`: open an interactive shell on a running container.
-
-Usage: `+prog+` [options] [username@]container-uuid [ssh-options] [remote-command [args...]]
-
-Options:
-`)
-		f.PrintDefaults()
-	}
 	detachKeys := f.String("detach-keys", "ctrl-],ctrl-]", "set detach key sequence, as in docker-attach(1)")
-	err := f.Parse(args)
-	if err != nil {
-		fmt.Fprintln(stderr, err)
-		return 2
-	}
-
-	if f.NArg() < 1 {
-		f.Usage()
+	if ok, code := cmd.ParseFlags(f, prog, args, "[username@]container-uuid [ssh-options] [remote-command [args...]]", stderr); !ok {
+		return code
+	} else if f.NArg() < 1 {
+		fmt.Fprintf(stderr, "missing required argument: container-uuid (try -help)\n")
 		return 2
 	}
 	target := f.Args()[0]
@@ -52,6 +41,32 @@ Options:
 	}
 	sshargs := f.Args()[1:]
 
+	// Try setting up a tunnel, and exit right away if it
+	// fails. This tunnel won't get used -- we'll set up a new
+	// tunnel when running as SSH client's ProxyCommand child --
+	// but in most cases where the real tunnel setup would fail,
+	// we catch the problem earlier here. This makes it less
+	// likely that an error message about tunnel setup will get
+	// hidden behind noisy errors from SSH client like this:
+	//
+	// [useful tunnel setup error message here]
+	// kex_exchange_identification: Connection closed by remote host
+	// Connection closed by UNKNOWN port 65535
+	// exit status 255
+	//
+	// In case our target is a container request, the probe also
+	// resolves it to a container, so we don't connect to two
+	// different containers in a race.
+	var probetarget bytes.Buffer
+	exitcode := connectSSHCommand{}.RunCommand(
+		"arvados-client connect-ssh",
+		[]string{"-detach-keys=" + *detachKeys, "-probe-only=true", target},
+		&bytes.Buffer{}, &probetarget, stderr)
+	if exitcode != 0 {
+		return exitcode
+	}
+	target = strings.Trim(probetarget.String(), "\n")
+
 	selfbin, err := os.Readlink("/proc/self/exe")
 	if err != nil {
 		fmt.Fprintln(stderr, err)
@@ -84,20 +99,24 @@ func (connectSSHCommand) RunCommand(prog string, args []string, stdin io.Reader,
 	f := flag.NewFlagSet(prog, flag.ContinueOnError)
 	f.SetOutput(stderr)
 	f.Usage = func() {
+		_, prog := filepath.Split(prog)
 		fmt.Fprint(stderr, prog+`: connect to the gateway service for a running container.
 
+NOTE: You almost certainly don't want to use this command directly. It
+is meant to be used internally. Use "arvados-client shell" instead.
+
 Usage: `+prog+` [options] [username@]container-uuid
 
 Options:
 `)
 		f.PrintDefaults()
 	}
+	probeOnly := f.Bool("probe-only", false, "do not transfer IO, just setup tunnel, print target UUID, and exit")
 	detachKeys := f.String("detach-keys", "", "set detach key sequence, as in docker-attach(1)")
-	if err := f.Parse(args); err != nil {
-		fmt.Fprintln(stderr, err)
-		return 2
+	if ok, code := cmd.ParseFlags(f, prog, args, "[username@]container-uuid", stderr); !ok {
+		return code
 	} else if f.NArg() != 1 {
-		f.Usage()
+		fmt.Fprintf(stderr, "missing required argument: [username@]container-uuid\n")
 		return 2
 	}
 	targetUUID := f.Args()[0]
@@ -106,6 +125,10 @@ Options:
 		loginUsername = targetUUID[:i]
 		targetUUID = targetUUID[i+1:]
 	}
+	if os.Getenv("ARVADOS_API_HOST") == "" || os.Getenv("ARVADOS_API_TOKEN") == "" {
+		fmt.Fprintln(stderr, "fatal: ARVADOS_API_HOST and ARVADOS_API_TOKEN environment variables are not set")
+		return 1
+	}
 	insecure := os.Getenv("ARVADOS_API_HOST_INSECURE")
 	rpcconn := rpc.NewConn("",
 		&url.URL{
@@ -137,7 +160,9 @@ Options:
 		fmt.Fprintf(stderr, "target UUID is not a container or container request UUID: %s\n", targetUUID)
 		return 1
 	}
-	sshconn, err := rpcconn.ContainerSSH(context.TODO(), arvados.ContainerSSHOptions{
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	sshconn, err := rpcconn.ContainerSSH(ctx, arvados.ContainerSSHOptions{
 		UUID:          targetUUID,
 		DetachKeys:    *detachKeys,
 		LoginUsername: loginUsername,
@@ -148,7 +173,11 @@ Options:
 	}
 	defer sshconn.Conn.Close()
 
-	ctx, cancel := context.WithCancel(context.Background())
+	if *probeOnly {
+		fmt.Fprintln(stdout, targetUUID)
+		return 0
+	}
+
 	go func() {
 		defer cancel()
 		_, err := io.Copy(stdout, sshconn.Conn)