Expand comma separated lists in global.cylc:[install][symlink dirs]

changes.d/6475.feat.md

@@ -0,0 +1 @@
+Allow definition of `install targets` in `global.cylc` using comma separated lists.

cylc/flow/cfgspec/globalcfg.py

@@ -587,6 +587,40 @@
     '''
 }
 
+COMMA_SEPARATED_SECTION_NOTE = '''
+
+
+    .. note::
+
+       This section can be a comma separated list.
+
+        .. spoiler:: Example
+
+            For example:
+
+            .. code-block:: cylc
+
+                [a, b]
+                    setting = x
+                [a]
+                    another_setting = y
+
+            Will become:
+
+            .. code-block:: cylc
+
+                [a]
+                    setting = x
+                [b]
+                    setting = x
+                [a]
+                    another_setting = y
+
+            Which will then be combined according to
+            :ref:`the rules for Cylc config syntax<syntax>`.
+
+'''
+
 # ----------------------------------------------------------------------------
 
 
@@ -1131,8 +1165,9 @@
 
             .. versionadded:: 8.0.0
         """):
-            with Conf('<install target>', desc="""
+            with Conf('<install target>', desc=f"""
                 :ref:`Host <Install targets>` on which to create the symlinks.
+                {COMMA_SEPARATED_SECTION_NOTE}
             """):
                 Conf('run', VDR.V_STRING, None, desc="""
                     Alternative location for the run dir.
@@ -1209,7 +1244,7 @@
 
         .. versionadded:: 8.0.0
     '''):
-        with Conf('<platform name>', desc='''
+        with Conf('<platform name>', desc=f'''
             Configuration defining a platform.
 
             Many of these settings have replaced those of the same name from
@@ -1219,7 +1254,7 @@
             Platform names can be regular expressions: If you have a set of
             compute resources such as ``bigmachine1, bigmachine2`` or
             ``desktop0000, .., desktop9999`` one would define platforms with
-            names ``[[bigmachine[12]]]`` and ``[[desktop[0-9]{4}]]``.
+            names ``[[bigmachine[12]]]`` and ``[[desktop[0-9]{{4}}]]``.
 
             Cylc searches for a matching platform in the reverse
             of the definition order to allow user defined platforms
@@ -1254,6 +1289,8 @@
                  platform configurations.
 
             .. versionadded:: 8.0.0
+
+            {COMMA_SEPARATED_SECTION_NOTE}
         ''') as Platform:
             with Conf('meta', desc=PLATFORM_META_DESCR):
                 Conf('<custom metadata>', VDR.V_STRING, '', desc='''
@@ -2018,6 +2055,7 @@
         self.dense.clear()
         LOG.debug("Loading site/user config files")
         conf_path_str = os.getenv("CYLC_CONF_PATH")
+
         if conf_path_str:
             # Explicit config file override.
             fname = os.path.join(conf_path_str, self.CONF_BASENAME)
@@ -2030,7 +2068,7 @@
 
         # Expand platforms needs to be performed first because it
         # manipulates the sparse config.
-        self._expand_platforms()
+        self._expand_commas()
 
         # Flesh out with defaults
         self.expand()
@@ -2074,8 +2112,8 @@
                     msg += f'\n * {name}'
                 raise GlobalConfigError(msg)
 
-    def _expand_platforms(self):
-        """Expand comma separated platform names.
+    def _expand_commas(self):
+        """Expand comma separated section headers.
 
         E.G. turn [platforms][foo, bar] into [platforms][foo] and
         platforms[bar].
@@ -2084,6 +2122,13 @@
             self.sparse['platforms'] = expand_many_section(
                 self.sparse['platforms']
             )
+        if (
+            self.sparse.get("install")
+            and self.sparse["install"].get("symlink dirs")
+        ):
+            self.sparse["install"]["symlink dirs"] = expand_many_section(
+                self.sparse["install"]["symlink dirs"]
+            )
 
     def platform_dump(
         self,

tests/unit/cfgspec/test_globalcfg.py

@@ -74,9 +74,19 @@ def test_dump_platform_details(capsys, mock_global_config):
     assert expected == out
 
 
-def test_expand_platforms(tmp_path: Path, mock_global_config: Callable):
-    """It should expand comma separated platform definitions."""
+def test_expand_commas(tmp_path: Path, mock_global_config: Callable):
+    """It should expand comma separated platform and install target
+    definitions."""
     glblcfg: GlobalConfig = mock_global_config('''
+    [install]
+        [[symlink dirs]]
+            [[[foo, bar]]]
+                run = /x
+            [[[foo]]]
+                share = /y
+            [[[bar]]]
+                share = /z
+
     [platforms]
         [[foo]]
             [[[meta]]]
@@ -91,7 +101,7 @@ def test_expand_platforms(tmp_path: Path, mock_global_config: Callable):
             [[[meta]]]
                 x = 4
     ''')
-    glblcfg._expand_platforms()
+    glblcfg._expand_commas()
 
     # ensure the definition order is preserved
     assert glblcfg.get(['platforms']).keys() == [
@@ -102,12 +112,18 @@ def test_expand_platforms(tmp_path: Path, mock_global_config: Callable):
         'pub',
     ]
 
-    # ensure sections are correctly deep-merged
+    # ensure platform sections are correctly deep-merged
     assert glblcfg.get(['platforms', 'foo', 'meta', 'x']) == '1'
     assert glblcfg.get(['platforms', 'bar', 'meta', 'x']) == '3'
     assert glblcfg.get(['platforms', 'baz', 'meta', 'x']) == '3'
     assert glblcfg.get(['platforms', 'pub', 'meta', 'x']) == '4'
 
+    # ensure install target sections are correctly merged:
+    assert glblcfg.get(["install", "symlink dirs", "foo", "run"]) == "/x"
+    assert glblcfg.get(["install", "symlink dirs", "foo", "share"]) == "/y"
+    assert glblcfg.get(["install", "symlink dirs", "bar", "run"]) == "/x"
+    assert glblcfg.get(["install", "symlink dirs", "bar", "share"]) == "/z"
+
 
 @pytest.mark.parametrize(
     'src_dir, err_expected',