[k8s] Fix L40 detection for nvidia GFD labels (#4511)

Fix L40 detection

sky/provision/kubernetes/utils.py

@@ -340,14 +340,15 @@ def get_accelerator_from_label_value(cls, value: str) -> str:
         """
         canonical_gpu_names = [
             'A100-80GB', 'A100', 'A10G', 'H100', 'K80', 'M60', 'T4g', 'T4',
-            'V100', 'A10', 'P4000', 'P100', 'P40', 'P4', 'L4'
+            'V100', 'A10', 'P4000', 'P100', 'P40', 'P4', 'L40', 'L4'
         ]
         for canonical_name in canonical_gpu_names:
             # A100-80G accelerator is A100-SXM-80GB or A100-PCIE-80GB
             if canonical_name == 'A100-80GB' and re.search(
                     r'A100.*-80GB', value):
                 return canonical_name
-            elif canonical_name in value:
+            # Use word boundary matching to prevent substring matches
+            elif re.search(rf'\b{re.escape(canonical_name)}\b', value):
                 return canonical_name
 
         # If we didn't find a canonical name:

tests/unit_tests/kubernetes/test_gpu_label_formatters.py

@@ -0,0 +1,22 @@
+"""Tests for GPU label formatting in Kubernetes integration.
+
+Tests verify correct GPU detection from Kubernetes labels.
+"""
+import pytest
+
+from sky.provision.kubernetes.utils import GFDLabelFormatter
+
+
+def test_gfd_label_formatter():
+    """Test word boundary regex matching in GFDLabelFormatter."""
+    # Test various GPU name patterns
+    test_cases = [
+        ('NVIDIA-L4-24GB', 'L4'),
+        ('NVIDIA-L40-48GB', 'L40'),
+        ('NVIDIA-L400', 'L400'),  # Should not match L4 or L40
+        ('NVIDIA-L4', 'L4'),
+        ('L40-GPU', 'L40'),
+    ]
+    for input_value, expected in test_cases:
+        result = GFDLabelFormatter.get_accelerator_from_label_value(input_value)
+        assert result == expected, f'Failed for {input_value}'