Exclude shared directories when creating environments

If we try to create a new environment from a shared configuration inside
the same repository, we can produce an infinite loop by copying the
environment into itself. Ignore any existing environments directory
during environment creation.

Change-Id: Ic9d3d03192f515a055e41351a0bf25da7a7b0684
Story: 2002009
Task: 40038

doc/source/multiple-environments.rst

@@ -261,5 +261,6 @@ configurations.
    (kayobe) $ kayobe environment create --source-config-path ~/kayobe-config-staging/etc/kayobe \
                   --environment staging
 
-This command recursively copies files and directories under the existing
-configuration. Merging shared configuration must be done manually.
+This command recursively copies files and directories (except the
+``environments`` directory if one exists) under the existing configuration to a
+new environment. Merging shared configuration must be done manually.

kayobe/environment.py

@@ -61,4 +61,4 @@ def create_kayobe_environment(parsed_args):
 
     source_config_path = parsed_args.source_config_path
     if source_config_path:
-        utils.copy_dir(source_config_path, env_path)
+        utils.copy_dir(source_config_path, env_path, exclude=["environments"])

kayobe/tests/unit/test_environment.py

@@ -80,4 +80,5 @@ class TestCase(unittest.TestCase):
         ]
         self.assertEqual(expected_calls, mock_mkdir.call_args_list)
         mock_copy_dir.assert_called_once_with(
-            "/path/to/foo", "/path/to/config/environments/foo")
+            "/path/to/foo", "/path/to/config/environments/foo",
+            exclude=["environments"])

kayobe/utils.py

@@ -225,14 +225,27 @@ def intersect_limits(args_limit, cli_limit):
     return separator.join(limits)
 
 
-def copy_dir(src, dest):
+def copy_dir(src, dest, exclude=None):
+    """Copy recursively a directory.
+
+    :param src: path of the source directory
+    :param dest: destination path, will be created if it does not exist
+    :param exclude: names of files or directories at the root of the source
+                    directory to exclude during copy
+    """
+    if exclude is None:
+        exclude = []
+
     if not os.path.isdir(dest):
-        shutil.copytree(src, dest)
-    else:
-        for file in os.listdir(src):
-            src_path = os.path.join(src, file)
-            dest_path = os.path.join(dest, file)
-            if os.path.isdir(src_path):
-                copy_dir(src_path, dest_path)
-            else:
-                shutil.copy2(src_path, dest_path)
+        os.mkdir(dest)
+
+    for file in os.listdir(src):
+        if file in exclude:
+            continue
+
+        src_path = os.path.join(src, file)
+        dest_path = os.path.join(dest, file)
+        if os.path.isdir(src_path):
+            copy_dir(src_path, dest_path)
+        else:
+            shutil.copy2(src_path, dest_path)