fix: localmode subprocess parent process not sending SIGTERM to child

setup.py

@@ -52,6 +52,7 @@ def read_version():
         "urllib3>=1.21.1,!=1.25,!=1.25.1",
         "docker-compose>=1.25.2",
         "PyYAML>=5.3, <6",  # PyYAML version has to match docker-compose requirements
+        "psutil",
     ],
     "scipy": ["scipy>=0.19.0"],
 }

src/sagemaker/local/image.py

@@ -31,7 +31,10 @@
 import tempfile
 
 from distutils.spawn import find_executable
+from signal import SIGTERM
 from threading import Thread
+
+import psutil
 from six.moves.urllib.parse import urlparse
 
 import sagemaker
@@ -840,6 +843,8 @@ def run(self):
 
     def down(self):
         """Placeholder docstring"""
+        for process in psutil.Process(self.process.pid).children():
+            process.send_signal(SIGTERM)
         self.process.terminate()