[Core] Relax cluster name restrictions and process cluster names

sky/backends/backend.py

@@ -3,8 +3,13 @@
 from typing import Dict, Generic, Optional
 
 import sky
+from sky import sky_logging
 from sky.usage import usage_lib
 from sky.utils import timeline
+from sky.utils.common_utils import adjust_cluster_name
+from sky.utils.common_utils import check_cluster_name_is_valid
+
+logger = sky_logging.init_logger(__name__)
 
 if typing.TYPE_CHECKING:
     from sky import resources
@@ -51,6 +56,14 @@ def provision(
             retry_until_up: bool = False) -> Optional[_ResourceHandleType]:
         if cluster_name is None:
             cluster_name = sky.backends.backend_utils.generate_cluster_name()
+        else:
+            prev_cluster_name = cluster_name
+            cluster_name = adjust_cluster_name(cluster_name)
+            if prev_cluster_name != cluster_name:
+                logger.info(f'Changed cluster name from '
+                            f'"{prev_cluster_name}" to "{cluster_name}" '
+                            f'to ensure name is valid for provisioning')
+            check_cluster_name_is_valid(cluster_name)
         usage_lib.record_cluster_name_for_current_operation(cluster_name)
         usage_lib.messages.usage.update_actual_task(task)
         return self._provision(task, to_provision, dryrun, stream_logs,

sky/backends/cloud_vm_ray_backend.py

@@ -2185,9 +2185,6 @@ def provision_with_retries(
         # Retrying launchable resources.
         while True:
             try:
-                # Recheck cluster name as the 'except:' block below may
-                # change the cloud assignment.
-                to_provision.cloud.check_cluster_name_is_valid(cluster_name)
                 if dryrun:
                     cloud_user = None
                 else:
@@ -4386,12 +4383,6 @@ def _check_existing_cluster(
                 prev_cluster_status=prev_cluster_status,
                 prev_handle=handle)
         usage_lib.messages.usage.set_new_cluster()
-        # Use the task_cloud, because the cloud in `to_provision` can be changed
-        # later during the retry.
-        for resources in task.resources:
-            task_cloud = (resources.cloud
-                          if resources.cloud is not None else clouds.Cloud)
-            task_cloud.check_cluster_name_is_valid(cluster_name)
 
         if to_provision is None:
             # The cluster is recently terminated either by autostop or manually

sky/cli.py

@@ -3744,17 +3744,6 @@ def spot_launch(
         if prompt is not None:
             click.confirm(prompt, default=True, abort=True, show_default=True)
 
-    for task in dag.tasks:
-        # We try our best to validate the cluster name before we launch the
-        # task. If the cloud is not specified, this will only validate the
-        # cluster name against the regex, and the cloud-specific validation will
-        # be done by the spot controller when actually launching the spot
-        # cluster.
-        for resources in task.resources:
-            task_cloud = (resources.cloud
-                          if resources.cloud is not None else clouds.Cloud)
-            task_cloud.check_cluster_name_is_valid(name)
-
     sky.spot_launch(dag,
                     name,
                     detach_run=detach_run,

sky/clouds/cloud.py

@@ -1,14 +1,12 @@
 """Interfaces: clouds, regions, and zones."""
 import collections
 import enum
-import re
 import typing
 from typing import Dict, Iterator, List, Optional, Set, Tuple
 
 from sky import exceptions
 from sky import skypilot_config
 from sky.clouds import service_catalog
-from sky.skylet import constants
 from sky.utils import log_utils
 from sky.utils import ux_utils
 
@@ -486,28 +484,6 @@ def check_features_are_supported(
                     f'The following features are not supported by {cls._REPR}:'
                     '\n\t' + table.get_string().replace('\n', '\n\t'))
 
-    @classmethod
-    def check_cluster_name_is_valid(cls, cluster_name: str) -> None:
-        """Errors out on invalid cluster names not supported by cloud providers.
-
-        Bans (including but not limited to) names that:
-        - are digits-only
-        - contain underscore (_)
-
-        Raises:
-            exceptions.InvalidClusterNameError: If the cluster name is invalid.
-        """
-        if cluster_name is None:
-            return
-        valid_regex = constants.CLUSTER_NAME_VALID_REGEX
-        if re.fullmatch(valid_regex, cluster_name) is None:
-            with ux_utils.print_exception_no_traceback():
-                raise exceptions.InvalidClusterNameError(
-                    f'Cluster name "{cluster_name}" is invalid; '
-                    'ensure it is fully matched by regex (e.g., '
-                    'only contains lower letters, numbers and dash): '
-                    f'{valid_regex}')
-
     @classmethod
     def check_disk_tier_enabled(cls, instance_type: str,
                                 disk_tier: str) -> None:

sky/utils/common_utils.py

@@ -20,6 +20,7 @@
 import jsonschema
 import yaml
 
+from sky import exceptions
 from sky import sky_logging
 from sky.skylet import constants
 from sky.utils import ux_utils
@@ -29,6 +30,11 @@
 USER_HASH_LENGTH = 8
 USER_HASH_LENGTH_IN_CLUSTER_NAME = 4
 
+# Arbitrary letter to prepend to cloud cluster name if proposed
+# cluster name does not start with a letter. Certain clouds
+# require a name that starts with a letter
+CLUSTER_NAME_VALID_PREFIX = 'x'
+
 # We are using base36 to reduce the length of the hash. 2 chars -> 36^2 = 1296
 # possibilities. considering the final cluster name contains the prefix as well,
 # we should be fine with 2 chars.
@@ -116,6 +122,38 @@ def _base36_encode(num: int) -> str:
     return _base36_encode(int_value)
 
 
+def adjust_cluster_name(cluster_name: str) -> str:
+    adjusted_cluster_name_arr = []
+    for ch in cluster_name:
+        if ch.isalnum() or ch == '-':
+            adjusted_cluster_name_arr.append(ch.lower())
+    if not adjusted_cluster_name_arr[0].isalpha():
+        adjusted_cluster_name_arr.insert(0, CLUSTER_NAME_VALID_PREFIX)
+    return ''.join(adjusted_cluster_name_arr)
+
+
+def check_cluster_name_is_valid(cluster_name: str) -> None:
+    """Errors out on invalid cluster names not supported by cloud providers.
+
+    Bans (including but not limited to) names that:
+    - are digits-only
+    - contain underscore (_)
+
+    Raises:
+        exceptions.InvalidClusterNameError: If the cluster name is invalid.
+    """
+    if cluster_name is None:
+        return
+    valid_regex = constants.CLUSTER_NAME_VALID_REGEX
+    if re.fullmatch(valid_regex, cluster_name) is None:
+        with ux_utils.print_exception_no_traceback():
+            raise exceptions.InvalidClusterNameError(
+                f'Cluster name "{cluster_name}" is invalid; '
+                'ensure it is fully matched by regex (e.g., '
+                'only contains lower letters, numbers and dash): '
+                f'{valid_regex}')
+
+
 def make_cluster_name_on_cloud(cluster_name: str,
                                max_length: Optional[int] = 15,
                                add_user_hash: bool = True) -> str:

tests/test_common_utils.py

@@ -0,0 +1,20 @@
+"""Tests for methods in common_utils.py"""
+from sky.utils.common_utils import adjust_cluster_name
+
+
+class TestAdjustClusterName:
+
+    def test_adjust_cluster_name_with_uppercase_letters(self):
+        assert adjust_cluster_name("LoRA") == "lora"
+
+    def test_adjust_cluster_name_with_underscore(self):
+        assert adjust_cluster_name("seed_1") == "seed1"
+
+    def test_adjust_cluster_name_with_period(self):
+        assert adjust_cluster_name("cuda11.8") == "cuda118"
+
+    def test_adjust_cluster_names_starting_with_number(self):
+        assert adjust_cluster_name("2bert") == "x2bert"
+
+    def test_adjust_cluster_name_with_multiple_invalid_characters(self):
+        assert adjust_cluster_name("2Lo_R.A") == "x2lora"