Fix version-aware image tag selection

Author: hubunt

llmdbenchmark/parser/version_resolver.py

@@ -1,6 +1,7 @@
 """Resolve ``"auto"`` image tags and chart versions via skopeo/helm."""
 
 import json
+import re
 import subprocess
 from copy import deepcopy
 
@@ -20,6 +21,19 @@ class VersionResolver:
     def __init__(self, logger, dry_run: bool = False):
         self.logger = logger
 
+    @staticmethod
+    def _latest_version_tag(tags: list[str]) -> str | None:
+        """Select the greatest tag using natural version-aware ordering."""
+
+        def version_key(tag: str) -> tuple:
+            return tuple(
+                (1, int(part), len(part)) if part.isdigit() else (0, part.casefold())
+                for part in re.split(r"(\d+)", tag)
+                if part
+            )
+
+        return max(tags, key=version_key) if tags else None
+
     def resolve_image_tag(self, registry: str, repository: str) -> str:
         """Resolve the latest tag for an image via skopeo, falling back to podman."""
         image_ref = repository
@@ -61,23 +75,24 @@ def _resolve_via_crane(self, image_ref: str) -> str | None:
                     for line in result.stdout.strip().split("\n")
                     if line.strip()
                 ]
-                if lines:
-                    return lines[-1]
+                return self._latest_version_tag(lines)
         except FileNotFoundError:
             pass
         return None
 
     def _resolve_via_skopeo(self, image_ref: str) -> str | None:
         """Resolve latest tag using skopeo list-tags."""
-        cmd = f"skopeo list-tags docker://{image_ref} | jq -r '.Tags[]' | sort -V"
+        cmd = ["skopeo", "list-tags", f"docker://{image_ref}"]
         try:
             result = subprocess.run(
-                cmd.split(), capture_output=True, text=True, check=True
+                cmd, capture_output=True, text=True, check=True
             )
             tags_data = json.loads(result.stdout)
             tags = tags_data.get("Tags", [])
-            if tags:
-                return tags[-1]
+            if isinstance(tags, list):
+                return self._latest_version_tag(
+                    [tag for tag in tags if isinstance(tag, str) and tag]
+                )
         except (subprocess.CalledProcessError, json.JSONDecodeError, FileNotFoundError):
             pass
         return None
@@ -90,12 +105,12 @@ def _resolve_via_podman(self, image_ref: str) -> str | None:
                 cmd.split(), capture_output=True, text=True, check=False
             )
             if result.returncode == 0:
-                lines = result.stdout.strip().split("\n")
-                if lines:
-                    last_line = lines[-1]
-                    parts = last_line.split()
-                    if len(parts) >= 2:
-                        return parts[1]
+                tags = []
+                for line in result.stdout.strip().split("\n"):
+                    parts = line.split()
+                    if len(parts) >= 2 and parts[1].casefold() != "tag":
+                        tags.append(parts[1])
+                return self._latest_version_tag(tags)
         except FileNotFoundError:
             pass
         return None

tests/test_version_resolver.py

@@ -6,6 +6,8 @@
 
 from __future__ import annotations
 
+import json
+from subprocess import CompletedProcess
 from typing import Any
 
 import pytest
@@ -75,6 +77,30 @@ def _images() -> dict:
     }
 
 
+# ---------------------------------------------------------------------------
+# Registry tag ordering
+# ---------------------------------------------------------------------------
+
+
+class TestRegistryTagOrdering:
+    def test_skopeo_selects_latest_tag_by_version(
+        self, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        tags = ["v0.20.1", "v0.9.2", "v0.10.0"]
+
+        def _run(*args: Any, **kwargs: Any) -> CompletedProcess[str]:
+            return CompletedProcess(args[0], 0, stdout=json.dumps({"Tags": tags}))
+
+        monkeypatch.setattr(
+            "llmdbenchmark.parser.version_resolver.subprocess.run", _run
+        )
+        resolver = VersionResolver(_StubLogger())
+
+        assert resolver._resolve_via_skopeo("docker.io/vllm/vllm-openai") == (
+            "v0.20.1"
+        )
+
+
 # ---------------------------------------------------------------------------
 # imageKey expansion
 # ---------------------------------------------------------------------------