[Core] Relax cluster name restriction and process cloud cluster name

sky/exceptions.py

@@ -213,6 +213,11 @@ class InvalidClusterNameError(Exception):
     pass
 
 
+class UnexpectedCharacterInClusterName(Exception):
+    """Raised when cluster name has unexpected character."""
+    pass
+
+
 class CloudUserIdentityError(Exception):
     """Raised when the cloud identity is invalid."""
     pass

sky/skylet/constants.py

@@ -93,7 +93,7 @@
 
 # In most clouds, cluster names can only contain lowercase letters, numbers
 # and hyphens. We use this regex to validate the cluster name.
-CLUSTER_NAME_VALID_REGEX = '[a-z]([-a-z0-9]*[a-z0-9])?'
+CLUSTER_NAME_VALID_REGEX = '[a-zA-Z]([-_.a-zA-Z0-9]*[a-zA-Z0-9])?'
 
 # Used for translate local file mounts to cloud storage. Please refer to
 # sky/execution.py::_maybe_translate_local_file_mounts_and_sync_up for

sky/utils/common_utils.py

@@ -117,44 +117,54 @@ def _base36_encode(num: int) -> str:
     return _base36_encode(int_value)
 
 
-def make_cluster_name_on_cloud(cluster_name: str,
+def make_cluster_name_on_cloud(display_name: str,
                                max_length: Optional[int] = 15,
                                add_user_hash: bool = True) -> str:
     """Generate valid cluster name on cloud that is unique to the user.
 
-    This is to map the cluster name to a valid length for cloud providers, e.g.
-    GCP limits the length of the cluster name to 35 characters. If the cluster
-    name with user hash is longer than max_length:
+    This is to map the cluster name to a valid length and character set for
+    cloud providers,
+    - e.g. GCP limits the length of the cluster name to 35 characters. If the
+    cluster name with user hash is longer than max_length:
       1. Truncate it to max_length - cluster_hash - user_hash_length.
       2. Append the hash of the cluster name
+    - e.g. Some cloud providers don't allow for uppercase letters, periods,
+    or underscores, so we map these to hyphens
 
     Args:
-        cluster_name: The cluster name to be truncated and hashed.
+        display_name: The cluster name to be truncated, hashed, and
+            transformed.
         max_length: The maximum length of the cluster name. If None, no
             truncation is performed.
         add_user_hash: Whether to append user hash to the cluster name.
     """
+
+    cluster_name_on_cloud = re.sub(r'[._]', '-', display_name).lower()
+    if display_name != cluster_name_on_cloud:
+        logger.debug(f'Cluster name will be called {cluster_name_on_cloud} on '
+                     f'the cloud. The user specified cluster name '
+                     f'("{display_name}") would be invalid in the cloud.')
     user_hash = ''
     if add_user_hash:
         user_hash = get_user_hash()[:USER_HASH_LENGTH_IN_CLUSTER_NAME]
         user_hash = f'-{user_hash}'
     user_hash_length = len(user_hash)
 
     if (max_length is None or
-            len(cluster_name) <= max_length - user_hash_length):
-        return f'{cluster_name}{user_hash}'
+            len(cluster_name_on_cloud) <= max_length - user_hash_length):
+        return f'{cluster_name_on_cloud}{user_hash}'
     # -1 is for the dash between cluster name and cluster name hash.
     truncate_cluster_name_length = (max_length - CLUSTER_NAME_HASH_LENGTH - 1 -
                                     user_hash_length)
-    truncate_cluster_name = cluster_name[:truncate_cluster_name_length]
+    truncate_cluster_name = cluster_name_on_cloud[:truncate_cluster_name_length]
     if truncate_cluster_name.endswith('-'):
         truncate_cluster_name = truncate_cluster_name.rstrip('-')
-    assert truncate_cluster_name_length > 0, (cluster_name, max_length)
-    cluster_name_hash = hashlib.md5(cluster_name.encode()).hexdigest()
+    assert truncate_cluster_name_length > 0, (cluster_name_on_cloud, max_length)
+    local_cluster_name_hash = hashlib.md5(display_name.encode()).hexdigest()
     # Use base36 to reduce the length of the hash.
-    cluster_name_hash = base36_encode(cluster_name_hash)
+    local_cluster_name_hash = base36_encode(local_cluster_name_hash)
     return (f'{truncate_cluster_name}'
-            f'-{cluster_name_hash[:CLUSTER_NAME_HASH_LENGTH]}{user_hash}')
+            f'-{local_cluster_name_hash[:CLUSTER_NAME_HASH_LENGTH]}{user_hash}')
 
 
 def cluster_name_in_hint(cluster_name: str, cluster_name_on_cloud: str) -> str:

tests/unit_tests/test_cloud.py

@@ -1,5 +1,6 @@
 import pytest
 
+from sky import exceptions
 from sky.clouds.cloud import Cloud
 
 
@@ -12,3 +13,23 @@ def test_cloud_get_reservations_available_resources(specific_reservations,
     available_resources = Cloud().get_reservations_available_resources(
         "instance_type", "region", "zone", specific_reservations)
     assert available_resources == expected
+
+
+class TestCheckClusterNameIsValid:
+
+    def test_check(self):
+        Cloud.check_cluster_name_is_valid("lora")
+
+    def test_check_with_hyphen(self):
+        Cloud.check_cluster_name_is_valid("seed-1")
+
+    def test_check_with_characters_to_transform(self):
+        Cloud.check_cluster_name_is_valid("Cuda_11.8")
+
+    def test_check_when_starts_with_number(self):
+        with pytest.raises(exceptions.InvalidClusterNameError):
+            Cloud.check_cluster_name_is_valid("11.8cuda")
+
+    def test_check_with_invalid_characters(self):
+        with pytest.raises(exceptions.InvalidClusterNameError):
+            Cloud.check_cluster_name_is_valid("lor@")

tests/unit_tests/test_common_utils.py

@@ -0,0 +1,25 @@
+from unittest.mock import patch
+
+from sky.utils import common_utils
+
+MOCKED_USER_HASH = 'ab12cd34'
+
+
+class TestMakeClusterNameOnCloud:
+
+    @patch('sky.utils.common_utils.get_user_hash')
+    def test_make(self, mock_get_user_hash):
+        mock_get_user_hash.return_value = MOCKED_USER_HASH
+        assert "lora-ab12" == common_utils.make_cluster_name_on_cloud("lora")
+
+    @patch('sky.utils.common_utils.get_user_hash')
+    def test_make_with_hyphen(self, mock_get_user_hash):
+        mock_get_user_hash.return_value = MOCKED_USER_HASH
+        assert "seed-1-ab12" == common_utils.make_cluster_name_on_cloud(
+            "seed-1")
+
+    @patch('sky.utils.common_utils.get_user_hash')
+    def test_make_with_characters_to_transform(self, mock_get_user_hash):
+        mock_get_user_hash.return_value = MOCKED_USER_HASH
+        assert "cuda-11-8-ab12" == common_utils.make_cluster_name_on_cloud(
+            "Cuda_11.8")