Add the --no-mac-metadata flag to fly tar commands

On recent MacOS machines, tar files created (i.e. from `fly execute`
with a local resource) include files prefixed by `._`.  As a result,
once you transfer this tar file to a Linux system and untar, these files
may interfere with jobs. This flag will prevent that from happening.

Fixes concourse#8916

See cloudfoundry/bosh-utils@f79167b
for a similar fix to the `bosh` cli.

go-archive/tarfs/shell_out.go

@@ -8,6 +8,7 @@ import (
  "io"
  "os"
  "os/exec"
+ "runtime"
  "strings"
  "syscall"
 )
@@ -38,7 +39,11 @@ func tarExtract(tarPath string, src io.Reader, dest string) error {
 func tarCompress(tarPath string, dest io.Writer, workDir string, paths ...string) error {
  out := new(bytes.Buffer)
 
- tarCmd := exec.Command(tarPath, "-cf", "-", "--null", "-T", "-")
+ args := []string{"-cf", "-", "--null", "-T", "-"}
+ if runtime.GOOS == "darwin" {
+ args = append([]string{"--no-mac-metadata"}, args...)
+ }
+ tarCmd := exec.Command(tarPath, args...)
  tarCmd.Dir = workDir
  tarCmd.Stderr = out
  tarCmd.Stdout = dest

go-archive/tgzfs/shell_out.go

@@ -8,6 +8,7 @@ import (
  "io"
  "os"
  "os/exec"
+ "runtime"
  "strings"
  "syscall"
 )
@@ -38,7 +39,11 @@ func tarExtract(tarPath string, src io.Reader, dest string) error {
 func tarCompress(tarPath string, dest io.Writer, workDir string, paths ...string) error {
  out := new(bytes.Buffer)
 
- tarCmd := exec.Command(tarPath, "-czf", "-", "--null", "-T", "-")
+ args := []string{"-czf", "-", "--null", "-T", "-"}
+ if runtime.GOOS == "darwin" {
+ args = append([]string{"--no-mac-metadata"}, args...)
+ }
+ tarCmd := exec.Command(tarPath, args...)
  tarCmd.Dir = workDir
  tarCmd.Stderr = out
  tarCmd.Stdout = dest