Add upload tests

These are skipped without the SSH_UPLOAD_TEST flag, since they require
connecting to a running ssh server on localhost as the current user, and
one creates a very large file.

communicator/ssh/communicator_test.go

@@ -3,9 +3,15 @@
 package ssh
 
 import (
+	"bufio"
 	"bytes"
 	"fmt"
+	"io"
+	"io/ioutil"
+	"math/rand"
 	"net"
+	"os"
+	"path/filepath"
 	"regexp"
 	"strings"
 	"testing"
@@ -165,6 +171,117 @@ func TestStart(t *testing.T) {
 	}
 }
 
+func TestAccUploadFile(t *testing.T) {
+	// use the local ssh server and scp binary to check uploads
+	if ok := os.Getenv("SSH_UPLOAD_TEST"); ok == "" {
+		t.Log("Skipping Upload Acceptance without SSH_UPLOAD_TEST set")
+		t.Skip()
+	}
+
+	r := &terraform.InstanceState{
+		Ephemeral: terraform.EphemeralState{
+			ConnInfo: map[string]string{
+				"type":    "ssh",
+				"user":    os.Getenv("USER"),
+				"host":    "127.0.0.1",
+				"port":    "22",
+				"timeout": "30s",
+			},
+		},
+	}
+
+	c, err := New(r)
+	if err != nil {
+		t.Fatalf("error creating communicator: %s", err)
+	}
+
+	tmpDir, err := ioutil.TempDir("", "communicator")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	content := []byte("this is the file content")
+	source := bytes.NewReader(content)
+	tmpFile := filepath.Join(tmpDir, "tempFile.out")
+	err = c.Upload(tmpFile, source)
+	if err != nil {
+		t.Fatalf("error uploading file: %s", err)
+	}
+
+	data, err := ioutil.ReadFile(tmpFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !bytes.Equal(data, content) {
+		t.Fatalf("bad: %s", data)
+	}
+}
+
+func TestAccHugeUploadFile(t *testing.T) {
+	// use the local ssh server and scp binary to check uploads
+	if ok := os.Getenv("SSH_UPLOAD_TEST"); ok == "" {
+		t.Log("Skipping Upload Acceptance without SSH_UPLOAD_TEST set")
+		t.Skip()
+	}
+
+	r := &terraform.InstanceState{
+		Ephemeral: terraform.EphemeralState{
+			ConnInfo: map[string]string{
+				"type":    "ssh",
+				"user":    os.Getenv("USER"),
+				"host":    "127.0.0.1",
+				"port":    "22",
+				"timeout": "30s",
+			},
+		},
+	}
+
+	c, err := New(r)
+	if err != nil {
+		t.Fatalf("error creating communicator: %s", err)
+	}
+
+	// copy 4GB of data, random to prevent compression.
+	size := int64(1 << 32)
+	source := io.LimitReader(rand.New(rand.NewSource(0)), size)
+
+	dest, err := ioutil.TempFile("", "communicator")
+	if err != nil {
+		t.Fatal(err)
+	}
+	destName := dest.Name()
+	dest.Close()
+	defer os.Remove(destName)
+
+	t.Log("Uploading to", destName)
+
+	// bypass the Upload method so we can directly supply the file size
+	// preventing the extra copy of the huge file.
+	targetDir := filepath.Dir(destName)
+	targetFile := filepath.Base(destName)
+
+	scpFunc := func(w io.Writer, stdoutR *bufio.Reader) error {
+		return scpUploadFile(targetFile, source, w, stdoutR, size)
+	}
+
+	err = c.scpSession("scp -vt "+targetDir, scpFunc)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// check the final file size
+	fs, err := os.Stat(destName)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if fs.Size() != size {
+		t.Fatalf("expected file size of %d, got %d", size, fs.Size())
+	}
+}
+
 func TestScriptPath(t *testing.T) {
 	cases := []struct {
 		Input   string