From dfd2a45f69d064f6854087360469a285905820bc Mon Sep 17 00:00:00 2001
From: Edward Oakes <ed.nmi.oakes@gmail.com>
Date: Mon, 2 Sep 2019 13:31:10 -0700
Subject: [PATCH] Simplify symlinking and don't print warnings (#5615)

---
 python/ray/node.py  |  4 ++--
 python/ray/utils.py | 41 +++++++++++++----------------------------
 2 files changed, 15 insertions(+), 30 deletions(-)

diff --git a/python/ray/node.py b/python/ray/node.py
index d22819b22..e016ffb75 100644
--- a/python/ray/node.py
+++ b/python/ray/node.py
@@ -19,7 +19,7 @@ import ray
 import ray.ray_constants as ray_constants
 import ray.services
 from ray.resource_spec import ResourceSpec
-from ray.utils import try_to_create_directory, try_to_symlink_directory
+from ray.utils import try_to_create_directory, try_to_symlink
 
 # Logger for this module. It should be configured at the entry point
 # into the program using Ray. Ray configures it by default automatically
@@ -176,7 +176,7 @@ class Node(object):
 
         # Send a warning message if the session exists.
         try_to_create_directory(self._session_dir)
-        try_to_symlink_directory(self._session_dir, session_symlink)
+        try_to_symlink(session_symlink, self._session_dir)
         # Create a directory to be used for socket files.
         self._sockets_dir = os.path.join(self._session_dir, "sockets")
         try_to_create_directory(self._sockets_dir, warn_if_exist=False)
diff --git a/python/ray/utils.py b/python/ray/utils.py
index c6016c43e..1914b2615 100644
--- a/python/ray/utils.py
+++ b/python/ray/utils.py
@@ -616,47 +616,32 @@ def try_to_create_directory(directory_path, warn_if_exist=True):
     try_make_directory_shared(directory_path)
 
 
-def try_to_symlink_directory(directory_path, symlink_path):
-    """Attempt to create a symlink to an existing directory.
+def try_to_symlink(symlink_path, target_path):
+    """Attempt to create a symlink.
 
-    If the directory doesn't exist, the symlink path exists, or the symlink
-    failed to be created, a warning will be logged and the symlink will not
-    be created. If a symlink exists in the path, it will be attempted to be
+    If the symlink path exists and isn't a symlink, the symlink will not be
+    created. If a symlink exists in the path, it will be attempted to be
     removed and replaced.
 
     Args:
-        directory_path: The path of the existing directory.
-        symlink_path: The path of the symlink to create.
+        symlink_path: The path at which to create the symlink.
+        target_path: The path the symlink should point to.
     """
-    logger = logging.getLogger("ray")
-    directory_path = os.path.expanduser(directory_path)
     symlink_path = os.path.expanduser(symlink_path)
-    if not os.path.exists(directory_path):
-        logger.warning("Attempted to create symlink to directory '{}', but "
-                       "the directory doesn't exist.".format(directory_path))
-        return
-    elif not os.path.isdir(directory_path):
-        logger.warning("Attempted to create symlink to directory '{}', but "
-                       "the '{}' isn't a directory.".format(
-                           directory_path, directory_path))
-        return
+    target_path = os.path.expanduser(target_path)
 
     if os.path.exists(symlink_path):
         if os.path.islink(symlink_path):
+            # Try to remove existing symlink.
             try:
                 os.remove(symlink_path)
-            except OSError as e:
-                logger.warning("Failed to remove existing symlink '{}': {}"
-                               .format(symlink_path, e))
+            except OSError:
                 return
         else:
-            logger.warning("Attempted to create symlink '{}' to directory '{}'"
-                           ", but the symlink path exists and isn't a symlink."
-                           .format(symlink_path, directory_path))
+            # There's an existing non-symlink file, don't overwrite it.
             return
 
     try:
-        os.symlink(directory_path, symlink_path)
-    except OSError as e:
-        logger.warning("Failed to create symlink '{}' to directory '{}': {}"
-                       .format(symlink_path, directory_path, e))
+        os.symlink(target_path, symlink_path)
+    except OSError:
+        return