Stop hardcoding the default Docker version (#445)

shub/image/utils.py

@@ -22,7 +22,6 @@
     from importlib import metadata
 
 
-DEFAULT_DOCKER_API_VERSION = '1.21'
 STATUS_FILE_LOCATION = '.releases'
 _VALIDSPIDERNAME = re.compile('^[a-z0-9][-._a-z0-9]+$', re.I)
 
@@ -39,10 +38,10 @@
     docker version
 
 and check its output: it should contain Docker client and server versions and
-should not contain any errors. The minimum API Version is: {}
+should not contain any errors.
 
 You can learn about Docker at https://www.docker.com/.
-""".format(DEFAULT_DOCKER_API_VERSION)
+"""
 
 
 def is_verbose():
@@ -103,7 +102,7 @@ def get_docker_client(validate=True):
             verify=apply_path_fun('ca.pem'),
             assert_hostname=False)
         docker_host = docker_host.replace('tcp://', 'https://')
-    version = os.environ.get('DOCKER_API_VERSION', DEFAULT_DOCKER_API_VERSION)
+    version = os.environ.get('DOCKER_API_VERSION', 'auto')
 
     # If it returns an error, check if you have the old docker-py installed
     # together with the new docker lib, and uninstall docker-py.

tests/image/test_utils.py

@@ -15,7 +15,6 @@
     load_status_url,
     store_status_url,
     STATUS_FILE_LOCATION,
-    DEFAULT_DOCKER_API_VERSION,
 )
 
 from .utils import FakeProjectDirectory, add_sh_fake_config
@@ -44,8 +43,7 @@ def version(self):
 
         mocked_docker.APIClient = DockerClientMock
         assert get_docker_client()
-        client_mock.assert_called_with(
-            base_url=None, tls=None, version=DEFAULT_DOCKER_API_VERSION)
+        client_mock.assert_called_with(base_url=None, tls=None, version='auto')
         # set basic test environment
         os.environ['DOCKER_HOST'] = 'http://127.0.0.1'
         os.environ['DOCKER_API_VERSION'] = '1.40'