golang 1.14 doesn't like calling NewFile on existing files. Port solution over from Terraform

command/console.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/chzyer/readline"
 	"github.com/hashicorp/packer/helper/wrappedreadline"
+	"github.com/hashicorp/packer/helper/wrappedstreams"
 	"github.com/hashicorp/packer/packer"
 	"github.com/hashicorp/packer/template"
 	"github.com/hashicorp/packer/template/interpolate"
@@ -115,7 +116,7 @@ func (*ConsoleCommand) AutocompleteFlags() complete.Flags {
 
 func (c *ConsoleCommand) modePiped(session *REPLSession) int {
 	var lastResult string
-	scanner := bufio.NewScanner(wrappedreadline.Stdin())
+	scanner := bufio.NewScanner(wrappedstreams.Stdin())
 	for scanner.Scan() {
 		result, err := session.Handle(strings.TrimSpace(scanner.Text()))
 		if err != nil {

command/meta.go

@@ -9,7 +9,7 @@ import (
 
 	kvflag "github.com/hashicorp/packer/helper/flag-kv"
 	sliceflag "github.com/hashicorp/packer/helper/flag-slice"
-	"github.com/hashicorp/packer/helper/wrappedreadline"
+	"github.com/hashicorp/packer/helper/wrappedstreams"
 	"github.com/hashicorp/packer/packer"
 	"github.com/hashicorp/packer/template"
 )
@@ -166,7 +166,7 @@ func (m *Meta) ValidateFlags() error {
 
 // StdinPiped returns true if the input is piped.
 func (m *Meta) StdinPiped() bool {
-	fi, err := wrappedreadline.Stdin().Stat()
+	fi, err := wrappedstreams.Stdin().Stat()
 	if err != nil {
 		// If there is an error, let's just say its not piped
 		return false

helper/wrappedreadline/wrappedreadline.go

@@ -1,5 +1,7 @@
-// Shamelessly copied from the Terraform repo because it wasn't worth vendoring
-// out two hundred lines of code so Packer could use it too.
+// STOLEN SHAMELESSLY FROM THE TERRAFORM REPO BECAUSE VENDORING OUT
+// WRAPPEDREADLINE AND WRAPPEDSTREAMS FELT LIKE TOO MUCH WORK.
+//
+// "a little copying is better than a lot of dependency"
 //
 // wrappedreadline is a package that has helpers for interacting with
 // readline from a panicwrap executable.
@@ -13,24 +15,24 @@
 package wrappedreadline
 
 import (
-	"os"
 	"runtime"
 
 	"github.com/chzyer/readline"
-	"github.com/mitchellh/panicwrap"
+
+	"github.com/hashicorp/packer/helper/wrappedstreams"
 )
 
 // Override overrides the values in readline.Config that need to be
 // set with wrapped values.
 func Override(cfg *readline.Config) *readline.Config {
-	cfg.Stdin = Stdin()
-	cfg.Stdout = Stdout()
-	cfg.Stderr = Stderr()
+	cfg.Stdin = wrappedstreams.Stdin()
+	cfg.Stdout = wrappedstreams.Stdout()
+	cfg.Stderr = wrappedstreams.Stderr()
 
 	cfg.FuncGetWidth = TerminalWidth
 	cfg.FuncIsTerminal = IsTerminal
 
-	rm := RawMode{StdinFd: int(Stdin().Fd())}
+	rm := RawMode{StdinFd: int(wrappedstreams.Stdin().Fd())}
 	cfg.FuncMakeRaw = rm.Enter
 	cfg.FuncExitRaw = rm.Exit
 
@@ -45,9 +47,9 @@ func IsTerminal() bool {
 	}
 
 	// Same implementation as readline but with our custom fds
-	return readline.IsTerminal(int(Stdin().Fd())) &&
-		(readline.IsTerminal(int(Stdout().Fd())) ||
-			readline.IsTerminal(int(Stderr().Fd())))
+	return readline.IsTerminal(int(wrappedstreams.Stdin().Fd())) &&
+		(readline.IsTerminal(int(wrappedstreams.Stdout().Fd())) ||
+			readline.IsTerminal(int(wrappedstreams.Stderr().Fd())))
 }
 
 // TerminalWidth gets the terminal width in characters.
@@ -78,43 +80,3 @@ func (r *RawMode) Exit() error {
 
 	return readline.Restore(r.StdinFd, r.state)
 }
-
-// Package provides access to the standard OS streams
-// (stdin, stdout, stderr) even if wrapped under panicwrap.
-// Stdin returns the true stdin of the process.
-func Stdin() *os.File {
-	stdin := os.Stdin
-	if panicwrap.Wrapped(nil) {
-		stdin = wrappedStdin
-	}
-
-	return stdin
-}
-
-// Stdout returns the true stdout of the process.
-func Stdout() *os.File {
-	stdout := os.Stdout
-	if panicwrap.Wrapped(nil) {
-		stdout = wrappedStdout
-	}
-
-	return stdout
-}
-
-// Stderr returns the true stderr of the process.
-func Stderr() *os.File {
-	stderr := os.Stderr
-	if panicwrap.Wrapped(nil) {
-		stderr = wrappedStderr
-	}
-
-	return stderr
-}
-
-// These are the wrapped standard streams. These are setup by the
-// platform specific code in initPlatform.
-var (
-	wrappedStdin  *os.File
-	wrappedStdout *os.File
-	wrappedStderr *os.File
-)

helper/wrappedreadline/wrappedreadline_unix.go

@@ -3,15 +3,16 @@
 package wrappedreadline
 
 import (
-	"os"
 	"syscall"
 	"unsafe"
+
+	"github.com/hashicorp/packer/helper/wrappedstreams"
 )
 
 // getWidth impl for Unix
 func getWidth() int {
-	stdoutFd := int(Stdout().Fd())
-	stderrFd := int(Stderr().Fd())
+	stdoutFd := int(wrappedstreams.Stdout().Fd())
+	stderrFd := int(wrappedstreams.Stderr().Fd())
 
 	w := getWidthFd(stdoutFd)
 	if w < 0 {
@@ -43,10 +44,3 @@ func getWidthFd(stdoutFd int) int {
 
 	return int(ws.Col)
 }
-
-func init() {
-	// The standard streams are passed in via extra file descriptors.
-	wrappedStdin = os.NewFile(uintptr(3), "stdin")
-	wrappedStdout = os.NewFile(uintptr(4), "stdout")
-	wrappedStderr = os.NewFile(uintptr(5), "stderr")
-}

helper/wrappedreadline/wrappedreadline_windows.go

@@ -2,56 +2,7 @@
 
 package wrappedreadline
 
-import (
-	"log"
-	"os"
-	"syscall"
-)
-
 // getWidth impl for other
 func getWidth() int {
 	return 0
 }
-
-func init() {
-	wrappedStdin = openConsole("CONIN$", os.Stdin)
-	wrappedStdout = openConsole("CONOUT$", os.Stdout)
-	wrappedStderr = wrappedStdout
-}
-
-// openConsole opens a console handle, using a backup if it fails.
-// This is used to get the exact console handle instead of the redirected
-// handles from panicwrap.
-func openConsole(name string, backup *os.File) *os.File {
-	// Convert to UTF16
-	path, err := syscall.UTF16PtrFromString(name)
-	if err != nil {
-		log.Printf("[ERROR] wrappedstreams: %s", err)
-		return backup
-	}
-
-	// Determine the share mode
-	var shareMode uint32
-	switch name {
-	case "CONIN$":
-		shareMode = syscall.FILE_SHARE_READ
-	case "CONOUT$":
-		shareMode = syscall.FILE_SHARE_WRITE
-	}
-
-	// Get the file
-	h, err := syscall.CreateFile(
-		path,
-		syscall.GENERIC_READ|syscall.GENERIC_WRITE,
-		shareMode,
-		nil,
-		syscall.OPEN_EXISTING,
-		0, 0)
-	if err != nil {
-		log.Printf("[ERROR] wrappedstreams: %s", err)
-		return backup
-	}
-
-	// Create the Go file
-	return os.NewFile(uintptr(h), name)
-}

helper/wrappedstreams/streams.go

@@ -0,0 +1,49 @@
+// STOLEN SHAMELESSLY FROM THE TERRAFORM REPO BECAUSE VENDORING OUT
+// WRAPPEDREADLINE AND WRAPPEDSTREAMS FELT LIKE TOO MUCH WORK.
+//
+// "a little copying is better than a lot of dependency"
+//
+// Package wrappedstreams provides access to the standard OS streams
+// (stdin, stdout, stderr) even if wrapped under panicwrap.
+package wrappedstreams
+
+import (
+	"os"
+
+	"github.com/mitchellh/panicwrap"
+)
+
+// Stdin returns the true stdin of the process.
+func Stdin() *os.File {
+	stdin, _, _ := fds()
+	return stdin
+}
+
+// Stdout returns the true stdout of the process.
+func Stdout() *os.File {
+	_, stdout, _ := fds()
+	return stdout
+}
+
+// Stderr returns the true stderr of the process.
+func Stderr() *os.File {
+	_, _, stderr := fds()
+	return stderr
+}
+
+func fds() (stdin, stdout, stderr *os.File) {
+	stdin, stdout, stderr = os.Stdin, os.Stdout, os.Stderr
+	if panicwrap.Wrapped(nil) {
+		initPlatform()
+		stdin, stdout, stderr = wrappedStdin, wrappedStdout, wrappedStderr
+	}
+	return
+}
+
+// These are the wrapped standard streams. These are setup by the
+// platform specific code in initPlatform.
+var (
+	wrappedStdin  *os.File
+	wrappedStdout *os.File
+	wrappedStderr *os.File
+)

helper/wrappedstreams/streams_other.go

@@ -0,0 +1,21 @@
+// +build !windows
+
+package wrappedstreams
+
+import (
+	"os"
+	"sync"
+)
+
+var initOnce sync.Once
+
+func initPlatform() {
+	// These must be initialized lazily, once it's been determined that this is
+	// a wrapped process.
+	initOnce.Do(func() {
+		// The standard streams are passed in via extra file descriptors.
+		wrappedStdin = os.NewFile(uintptr(3), "stdin")
+		wrappedStdout = os.NewFile(uintptr(4), "stdout")
+		wrappedStderr = os.NewFile(uintptr(5), "stderr")
+	})
+}

helper/wrappedstreams/streams_windows.go

@@ -0,0 +1,52 @@
+// +build windows
+
+package wrappedstreams
+
+import (
+	"log"
+	"os"
+	"syscall"
+)
+
+func initPlatform() {
+	wrappedStdin = openConsole("CONIN$", os.Stdin)
+	wrappedStdout = openConsole("CONOUT$", os.Stdout)
+	wrappedStderr = wrappedStdout
+}
+
+// openConsole opens a console handle, using a backup if it fails.
+// This is used to get the exact console handle instead of the redirected
+// handles from panicwrap.
+func openConsole(name string, backup *os.File) *os.File {
+	// Convert to UTF16
+	path, err := syscall.UTF16PtrFromString(name)
+	if err != nil {
+		log.Printf("[ERROR] wrappedstreams: %s", err)
+		return backup
+	}
+
+	// Determine the share mode
+	var shareMode uint32
+	switch name {
+	case "CONIN$":
+		shareMode = syscall.FILE_SHARE_READ
+	case "CONOUT$":
+		shareMode = syscall.FILE_SHARE_WRITE
+	}
+
+	// Get the file
+	h, err := syscall.CreateFile(
+		path,
+		syscall.GENERIC_READ|syscall.GENERIC_WRITE,
+		shareMode,
+		nil,
+		syscall.OPEN_EXISTING,
+		0, 0)
+	if err != nil {
+		log.Printf("[ERROR] wrappedstreams: %s", err)
+		return backup
+	}
+
+	// Create the Go file
+	return os.NewFile(uintptr(h), name)
+}