fix: remove docker-compose as a required dependency. (#1128)

* Remove docker-compose as a required dependency. Throw an error if it is not installed.
* Use distutils instead of shutil to support python2.

Author: nadiaya

setup.py

@@ -40,7 +40,6 @@ def read_version():
     "scipy>=0.19.0",
     "urllib3>=1.21, <1.25",
     "protobuf3-to-dict>=0.1.5",
-    "docker-compose>=1.23.0",
     "requests>=2.20.0, <2.21",
     "fabric>=2.0",
 ]
@@ -87,6 +86,7 @@ def read_version():
             "black==19.3b0 ; python_version >= '3.6'",
             "stopit==1.1.2",
             "apache-airflow==1.10.5",
+            "docker-compose>=1.23.0",
         ]
     },
     entry_points={"console_scripts": ["sagemaker=sagemaker.cli.main:main"]},

src/sagemaker/local/image.py

@@ -29,6 +29,7 @@
 import tarfile
 import tempfile
 
+from distutils.spawn import find_executable
 from threading import Thread
 from six.moves.urllib.parse import urlparse
 
@@ -77,6 +78,15 @@ def __init__(self, instance_type, instance_count, image, sagemaker_session=None)
         """
         from sagemaker.local.local_session import LocalSession
 
+        # check if docker-compose is installed
+        if find_executable("docker-compose") is None:
+            raise ImportError(
+                "'docker-compose' is not installed. "
+                "Local Mode features will not work without docker-compose. "
+                "For more information on how to install 'docker-compose', please, see "
+                "https://docs.docker.com/compose/install/"
+            )
+
         self.sagemaker_session = sagemaker_session or LocalSession()
         self.instance_type = instance_type
         self.instance_count = instance_count