Do not set attributes when spawning the getter child (#16791)

* Do not set attributes when spawning the getter child

* Cleanup

* Cleanup

---------

Co-authored-by: the-nando <the-nando@invalid.local>

.changelog/16791.txt

@@ -0,0 +1,3 @@
+```release-note:bug
+client: Remove setting attributes when spawning the getter child
+```

client/allocrunner/taskrunner/getter/testing.go

@@ -24,24 +24,19 @@ func TestSandbox(t *testing.T) *Sandbox {
 }
 
 // SetupDir creates a directory suitable for testing artifact - i.e. it is
-// owned by the nobody user as would be the case in a normal client operation.
+// owned by the user under which nomad runs.
 //
 // returns alloc_dir, task_dir
 func SetupDir(t *testing.T) (string, string) {
-	uid, gid := credentials()
-
 	allocDir := t.TempDir()
 	taskDir := filepath.Join(allocDir, "local")
 	topDir := filepath.Dir(allocDir)
 
-	must.NoError(t, os.Chown(topDir, int(uid), int(gid)))
 	must.NoError(t, os.Chmod(topDir, 0o755))
 
-	must.NoError(t, os.Chown(allocDir, int(uid), int(gid)))
 	must.NoError(t, os.Chmod(allocDir, 0o755))
 
 	must.NoError(t, os.Mkdir(taskDir, 0o755))
-	must.NoError(t, os.Chown(taskDir, int(uid), int(gid)))
 	must.NoError(t, os.Chmod(taskDir, 0o755))
 	return allocDir, taskDir
 }

client/allocrunner/taskrunner/getter/util.go

@@ -137,7 +137,6 @@ func (s *Sandbox) runCmd(env *parameters) error {
 	cmd.Stdin = env.reader()
 	cmd.Stdout = output
 	cmd.Stderr = output
-	cmd.SysProcAttr = attributes()
 
 	// start & wait for the subprocess to terminate
 	if err := cmd.Run(); err != nil {

client/allocrunner/taskrunner/getter/util_default.go

@@ -4,19 +4,8 @@ package getter
 
 import (
 	"path/filepath"
-	"syscall"
 )
 
-// attributes is not implemented by default
-func attributes() *syscall.SysProcAttr {
-	return nil
-}
-
-// credentials is not implemented by default
-func credentials() (uint32, uint32) {
-	return 0, 0
-}
-
 // lockdown is not implemented by default
 func lockdown(string, string) error {
 	return nil

client/allocrunner/taskrunner/getter/util_linux.go

@@ -5,45 +5,12 @@ package getter
 import (
 	"os"
 	"path/filepath"
-	"syscall"
 
 	"github.com/mitchellh/go-homedir"
 	"github.com/shoenig/go-landlock"
 	"golang.org/x/sys/unix"
 )
 
-var (
-	// userUID is the current user's uid
-	userUID uint32
-
-	// userGID is the current user's gid
-	userGID uint32
-)
-
-func init() {
-	userUID = uint32(syscall.Getuid())
-	userGID = uint32(syscall.Getgid())
-}
-
-// attributes returns the system process attributes to run
-// the sandbox process with
-func attributes() *syscall.SysProcAttr {
-	uid, gid := credentials()
-	return &syscall.SysProcAttr{
-		Credential: &syscall.Credential{
-			Uid: uid,
-			Gid: gid,
-		},
-	}
-}
-
-// credentials returns the UID and GID of the user the child process
-// will run as - for now this is always the same user the Nomad agent is
-// running as.
-func credentials() (uint32, uint32) {
-	return userUID, userGID
-}
-
 // findHomeDir returns the home directory as provided by os.UserHomeDir. In case
 // os.UserHomeDir returns an error, we return /root if the current process is being
 // run by root, or /dev/null otherwise.

client/allocrunner/taskrunner/getter/util_windows.go

@@ -5,19 +5,8 @@ package getter
 import (
 	"os"
 	"path/filepath"
-	"syscall"
 )
 
-// attributes is not implemented on Windows
-func attributes() *syscall.SysProcAttr {
-	return nil
-}
-
-// credentials is not implemented on Windows
-func credentials() (uint32, uint32) {
-	return 0, 0
-}
-
 // lockdown is not implemented on Windows
 func lockdown(string, string) error {
 	return nil