Add '_test_server' hidden handler

examples/integration/_client.sh

@@ -51,3 +51,6 @@ ssh sshportal -l admin config backup --indent --ignore-events  > backup-2
     set -xe
     diff backup-1.clean backup-2.clean
 )
+
+# bastion
+# TODO

main.go

@@ -2,19 +2,25 @@ package main
 
 import (
 	"bytes"
+	"encoding/json"
 	"fmt"
+	"io"
 	"log"
 	"math/rand"
 	"net"
 	"os"
+	"os/exec"
 	"path"
 	"strings"
+	"syscall"
 	"time"
+	"unsafe"
 
 	"github.com/gliderlabs/ssh"
 	"github.com/jinzhu/gorm"
 	_ "github.com/jinzhu/gorm/dialects/mysql"
 	_ "github.com/jinzhu/gorm/dialects/sqlite"
+	"github.com/kr/pty"
 	"github.com/urfave/cli"
 	gossh "golang.org/x/crypto/ssh"
 )
@@ -87,6 +93,10 @@ func main() {
 					Usage: "Do not print errors, if any",
 				},
 			},
+		}, {
+			Name:   "_test_server",
+			Hidden: true,
+			Action: testServer,
 		},
 	}
 	if err := app.Run(os.Args); err != nil {
@@ -224,3 +234,68 @@ func healthcheckOnce(addr string, config gossh.ClientConfig, quiet bool) error {
 	}
 	return nil
 }
+
+// testServer is an hidden handler used for integration tests
+func testServer(c *cli.Context) error {
+	ssh.Handle(func(s ssh.Session) {
+		helloMsg := struct {
+			User    string
+			Environ []string
+			Command []string
+		}{
+			User:    s.User(),
+			Environ: s.Environ(),
+			Command: s.Command(),
+		}
+		enc := json.NewEncoder(s)
+		if err := enc.Encode(&helloMsg); err != nil {
+			log.Fatalf("failed to write helloMsg: %v", err)
+		}
+		var cmd *exec.Cmd
+		if s.Command() == nil {
+			cmd = exec.Command("/bin/sh") // #nosec
+		} else {
+			cmd = exec.Command(s.Command()[0], s.Command()[1:]...) // #nosec
+		}
+		ptyReq, winCh, isPty := s.Pty()
+		var cmdErr error
+		if isPty {
+			cmd.Env = append(cmd.Env, fmt.Sprintf("TERM=%s", ptyReq.Term))
+			f, err := pty.Start(cmd)
+			if err != nil {
+				fmt.Fprintf(s, "failed to run command: %v\n", err)
+				_ = s.Exit(1)
+				return
+			}
+			go func() {
+				for win := range winCh {
+					_, _, _ = syscall.Syscall(syscall.SYS_IOCTL, f.Fd(), uintptr(syscall.TIOCSWINSZ),
+						uintptr(unsafe.Pointer(&struct{ h, w, x, y uint16 }{uint16(win.Height), uint16(win.Width), 0, 0}))) // #nosec
+				}
+			}()
+			go func() {
+				_, _ = io.Copy(f, s) // stdin
+			}()
+			_, _ = io.Copy(s, f) // stdout
+			cmdErr = cmd.Wait()
+		} else {
+			//cmd.Stdin = s
+			cmd.Stdout = s
+			cmd.Stderr = s
+			cmdErr = cmd.Run()
+		}
+
+		if cmdErr != nil {
+			if exitError, ok := cmdErr.(*exec.ExitError); ok {
+				waitStatus := exitError.Sys().(syscall.WaitStatus)
+				_ = s.Exit(waitStatus.ExitStatus())
+				return
+			}
+		}
+		waitStatus := cmd.ProcessState.Sys().(syscall.WaitStatus)
+		_ = s.Exit(waitStatus.ExitStatus())
+	})
+
+	log.Println("starting ssh server on port 2222...")
+	return ssh.ListenAndServe(":2222", nil)
+}