[ez][BE] Tag deletion script to delete any old ciflow + autorevert tags (#157468)

Change the branch/tag deletion script that runs once per day to delete more tags

Previous: only delete ciflow tags that didn't correspond to an open PR
New: delete ciflow tags attached to commits that are > 7 days old.  Also delete `trunk/<sha>` (I think they are for autorevert) tags that are attached to commits that are > 7 days old

It's hard to figure out when the actual tag was pushed or created, so instead it looks at the commit date, which might lead to unexpected behavior if the tag was pushed much later than the commit (ex triggering periodic later to bisect).  I think it's ok though since you don't really need the tag after the workflow runs
Pull Request resolved: https://github.com/pytorch/pytorch/pull/157468
Approved by: https://github.com/izaitsevfb

.github/scripts/delete_old_branches.py

@@ -275,7 +275,7 @@ def delete_branches() -> None:
         delete_branch(git_repo, branch)
 
 
-def delete_old_ciflow_tags() -> None:
+def delete_old_tags() -> None:
     # Deletes ciflow tags if they are associated with a closed PR or a specific
     # commit.  Lightweight tags don't have information about the date they were
     # created, so we can't check how old they are.  The script just assumes that
@@ -288,23 +288,29 @@ def delete_old_ciflow_tags() -> None:
         delete_branch(git_repo, f"refs/tags/{tag}")
 
     tags = git_repo._run_git("tag").splitlines()
-    open_pr_numbers = [x["number"] for x in get_open_prs()]
 
+    CIFLOW_TAG_REGEX = re.compile(r"^ciflow\/.*\/(\d{5,6}|[0-9a-f]{40})$")
+    AUTO_REVERT_TAG_REGEX = re.compile(r"^trunk\/[0-9a-f]{40}$")
     for tag in tags:
         try:
             if ESTIMATED_TOKENS[0] > 400:
                 print("Estimated tokens exceeded, exiting")
                 break
-            if not tag.startswith("ciflow/"):
+
+            if not CIFLOW_TAG_REGEX.match(tag) and not AUTO_REVERT_TAG_REGEX.match(tag):
                 continue
-            re_match_pr = re.match(r"^ciflow\/.*\/(\d{5,6})$", tag)
-            re_match_sha = re.match(r"^ciflow\/.*\/([0-9a-f]{40})$", tag)
-            if re_match_pr:
-                pr_number = int(re_match_pr.group(1))
-                if pr_number in open_pr_numbers:
-                    continue
-                delete_tag(tag)
-            elif re_match_sha:
+
+            # This checks the date of the commit associated with the tag instead
+            # of the tag itself since lightweight tags don't have this
+            # information.  I think it should be ok since this only runs once a
+            # day
+            tag_info = git_repo._run_git("show", "-s", "--format=%ct", tag)
+            tag_timestamp = int(tag_info.strip())
+            # Maybe some timezone issues, but a few hours shouldn't matter
+            tag_age_days = (datetime.now().timestamp() - tag_timestamp) / SEC_IN_DAY
+
+            if tag_age_days > 7:
+                print(f"[{tag}] Tag is older than 7 days, deleting")
                 delete_tag(tag)
         except Exception as e:
             print(f"Failed to check tag {tag}: {e}")
@@ -312,4 +318,4 @@ def delete_old_ciflow_tags() -> None:
 
 if __name__ == "__main__":
     delete_branches()
-    delete_old_ciflow_tags()
+    delete_old_tags()

.github/scripts/test_delete_old_branches.py

@@ -0,0 +1,56 @@
+import os
+import unittest
+from datetime import datetime
+from unittest.mock import MagicMock, patch
+
+
+os.environ["GITHUB_TOKEN"] = "test_token"
+
+from delete_old_branches import delete_old_tags
+
+
+@patch("delete_old_branches.delete_branch")
+@patch("gitutils.GitRepo._run_git")
+class TestDeleteTag(unittest.TestCase):
+    def test_delete_tag(
+        self, mock_run_git: "MagicMock", mock_delete_tag: "MagicMock"
+    ) -> None:
+        for tag in [
+            "ciflow/branch/12345",
+            "ciflow/commitsha/1234567890abcdef1234567890abcdef12345678",
+            "trunk/1234567890abcdef1234567890abcdef12345678",
+        ]:
+            mock_run_git.side_effect = [
+                tag,
+                str(int(datetime.now().timestamp() - 8 * 24 * 60 * 60)),  # 8 days ago
+            ]
+            delete_old_tags()
+            mock_delete_tag.assert_called_once()
+            mock_delete_tag.reset_mock()
+
+            # Don't delete if the tag is not old enough
+            mock_run_git.side_effect = [
+                tag,
+                str(int(datetime.now().timestamp() - 6 * 24 * 60 * 60)),  # 6 days ago
+            ]
+            delete_old_tags()
+            mock_delete_tag.assert_not_called()
+
+    def test_do_not_delete_tag(
+        self, mock_run_git: "MagicMock", mock_delete_tag: "MagicMock"
+    ) -> None:
+        for tag in [
+            "ciflow/doesntseemtomatch",
+            "trunk/doesntseemtomatch",
+            "doesntseemtomatch",
+        ]:
+            mock_run_git.side_effect = [
+                tag,
+                str(int(datetime.now().timestamp() - 8 * 24 * 60 * 60)),  # 8 days ago
+            ]
+            delete_old_tags()
+            mock_delete_tag.assert_not_called()
+
+
+if __name__ == "__main__":
+    unittest.main()