Stop searching platform groups after first match.

cylc · Mar 7, 2023 · d3ce313 · d3ce313
1 parent 62fdc6e
commit d3ce313
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Showing 2 changed files with 16 additions and 5 deletions.
diff --git a/cylc/flow/platforms.py b/cylc/flow/platforms.py
@@ -191,13 +191,17 @@ def platform_from_name(
         platform_name = 'localhost'
 
     platform_group = None
+    # The list is reversed to allow user-set platform groups (which are loaded
+    # later than site set platforms) to be matched first and override site
+    # defined platforms.
     for platform_name_re in reversed(list(platform_groups)):
         # Platform is member of a group.
         if re.fullmatch(platform_name_re, platform_name):
             platform_name = get_platform_from_group(
                 platform_groups[platform_name_re], group_name=platform_name,
                 bad_hosts=bad_hosts
             )
+            break
 
     for platform_name_re in list(platforms):
         if (

diff --git a/tests/unit/test_platforms_get_platform.py b/tests/unit/test_platforms_get_platform.py
@@ -237,18 +237,25 @@ def test_get_platform_using_platform_name_from_job_info(
 
 
 def test_get_platform_groups_basic(mock_glbl_cfg):
-    # get platform from group works.
+    """get platform from group works.
+
+    Additionally, ensure that we stop after selecting the first
+    appropriate platform.
+    """
     mock_glbl_cfg(
         'cylc.flow.platforms.glbl_cfg',
         '''
         [platforms]
-            [[aleph]]
-                hosts = aleph
-            [[bet]]
-                hosts = bet
+            [[aleph, bet, alpha, beta]]
 
         [platform groups]
             [[hebrew_letters]]
+                platforms = alpha, beta
+                [[[selection]]]
+                    method = definition order
+            [[aleph]]
+                platforms = alpha
+            [[.*_letters]]
                 platforms = aleph, bet
                 [[[selection]]]
                     method = definition order