Files
rclone/backend/sftp/ssh_external_test.go
copilot-swe-agent[bot] 4f5efe2871 Fix zombie SSH processes with --sftp-ssh by ensuring Wait() is called only once
The issue was that cmd.Wait() was being called multiple times on the same
process - once in the background goroutine and once in Close(). This could
lead to zombie processes because only the first call to Wait() properly
reaps the process.

The fix uses sync.Once to ensure Wait() is only called once per SSH process,
storing and returning the result on subsequent calls.

Added tests to verify the fix works correctly.

Co-authored-by: ncw <536803+ncw@users.noreply.github.com>
2025-10-30 17:56:13 +00:00

85 lines
2.0 KiB
Go

//go:build !plan9
package sftp
import (
"testing"
"time"
"github.com/rclone/rclone/fs"
"github.com/stretchr/testify/assert"
)
// TestSSHExternalWaitMultipleCalls verifies that calling Wait() multiple times
// doesn't cause zombie processes
func TestSSHExternalWaitMultipleCalls(t *testing.T) {
// Create a minimal Fs object for testing
opt := &Options{
SSH: fs.SpaceSepList{"echo", "test"},
}
f := &Fs{
opt: *opt,
}
// Create a new SSH session
session := f.newSSHSessionExternal()
// Start a simple command that exits quickly
err := session.Start("exit 0")
assert.NoError(t, err)
// Give the command time to complete
time.Sleep(100 * time.Millisecond)
// Call Wait() multiple times - this should not cause issues
err1 := session.Wait()
err2 := session.Wait()
err3 := session.Wait()
// All calls should return the same result (no error in this case)
assert.NoError(t, err1)
assert.NoError(t, err2)
assert.NoError(t, err3)
// Verify the process has exited
assert.True(t, session.exited())
}
// TestSSHExternalCloseMultipleCalls verifies that calling Close() multiple times
// followed by Wait() calls doesn't cause zombie processes
func TestSSHExternalCloseMultipleCalls(t *testing.T) {
// Create a minimal Fs object for testing
opt := &Options{
SSH: fs.SpaceSepList{"sleep", "10"},
}
f := &Fs{
opt: *opt,
}
// Create a new SSH session
session := f.newSSHSessionExternal()
// Start a long-running command
err := session.Start("sleep 10")
if err != nil {
t.Skip("Cannot start sleep command:", err)
}
// Close should cancel and wait for the process
_ = session.Close()
// Additional Wait() calls should return the same error
err2 := session.Wait()
err3 := session.Wait()
// All should complete without panicking
// err1 could be nil or an error depending on how the process was killed
// err2 and err3 should be the same
assert.Equal(t, err2, err3, "Subsequent Wait() calls should return same result")
// Verify the process has exited
assert.True(t, session.exited())
}