Backport of ansible-collections/community.general@07e8911fd8 to stable-2.9.

changelogs/fragments/community.general-80-update_docker_connection_plugin.yml

@@ -0,0 +1,2 @@
+bugfixes:
+  - docker connection plugin - do not prefix remote path if running on Windows containers.

lib/ansible/plugins/connection/docker.py

@@ -275,9 +275,13 @@ class Connection(ConnectionBase):
 
             Can revisit using $HOME instead if it's a problem
         '''
-        if not remote_path.startswith(os.path.sep):
-            remote_path = os.path.join(os.path.sep, remote_path)
-        return os.path.normpath(remote_path)
+        if getattr(self._shell, "_IS_WINDOWS", False):
+            import ntpath
+            return ntpath.normpath(remote_path)
+        else:
+            if not remote_path.startswith(os.path.sep):
+                remote_path = os.path.join(os.path.sep, remote_path)
+            return os.path.normpath(remote_path)
 
     def put_file(self, in_path, out_path):
         """ Transfer a file from local to docker container """
@@ -329,7 +333,11 @@ class Connection(ConnectionBase):
                              stdout=subprocess.PIPE, stderr=subprocess.PIPE)
         p.communicate()
 
-        actual_out_path = os.path.join(out_dir, os.path.basename(in_path))
+        if getattr(self._shell, "_IS_WINDOWS", False):
+            import ntpath
+            actual_out_path = ntpath.join(out_dir, ntpath.basename(in_path))
+        else:
+            actual_out_path = os.path.join(out_dir, os.path.basename(in_path))
 
         if p.returncode != 0:
             # Older docker doesn't have native support for fetching files command `cp`