From 4a343846ab50d8ddc70fb9dde72c0477eab221e8 Mon Sep 17 00:00:00 2001
From: Tim Pillinger <26465611+wxtim@users.noreply.github.com>
Date: Mon, 4 Dec 2023 11:07:21 +0000
Subject: [PATCH] Ensure that the cached globalconfig object is reloaded after
 the export of `CYLC_SYMLINKS` variable. This means that using the
 `CYLC_SYMLINKS` variable allows users to specify installation symlink
 locations in the `rose-suite.conf`.

---
 CHANGES.md                     |  9 +++++++++
 cylc/rose/utilities.py         |  8 ++++++++
 tests/functional/test_utils.py | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/CHANGES.md b/CHANGES.md
index 27af8c00..a80577f2 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -6,6 +6,15 @@ creating a new release entry be sure to copy & paste the span tag with the
 updated. Only the first match gets replaced, so it's fine to leave the old
 ones in. -->
 
+
+## __cylc-rose-1.4.0 (<span actions:bind='release-date'>Upcoming</span>)__
+
+### Features
+
+[#269](://github.com/cylc/cylc-rose/pull/269) - Reload the Cylc Global
+config after exporting CYLC_SYMLINKS variable. This change will allow
+users to set symlink directory locations in their `rose-suite.conf`.
+
 ## __cylc-rose-1.3.1 (<span actions:bind='release-date'>Released 2023-10-24</span>)__
 
 ### Fixes
diff --git a/cylc/rose/utilities.py b/cylc/rose/utilities.py
index e23f6e54..c6e1b8af 100644
--- a/cylc/rose/utilities.py
+++ b/cylc/rose/utilities.py
@@ -27,6 +27,7 @@
 from cylc.flow import LOG
 from cylc.flow.exceptions import CylcError
 from cylc.flow.flags import cylc7_back_compat
+from cylc.flow.cfgspec.glbl_cfg import glbl_cfg
 from cylc.flow.hostuserutil import get_host
 from metomi.isodatetime.datetimeoper import DateTimeOperator
 from metomi.rose import __version__ as ROSE_VERSION
@@ -869,6 +870,13 @@ def export_environment(environment: Dict[str, str]) -> None:
     for key, val in environment.items():
         os.environ[key] = val
 
+    # If CYLC_SYMLINKS has been set we want to force reload
+    # the global config so that the value of CYLC_SYMLINKS
+    # can be used by Jinja2 in the global config.
+    # https://github.com/cylc/cylc-rose/issues/237
+    if 'CYLC_SYMLINKS' in environment:
+        glbl_cfg().load()
+
 
 def record_cylc_install_options(
     srcdir: Path,
diff --git a/tests/functional/test_utils.py b/tests/functional/test_utils.py
index f2b9ef07..3b784e09 100644
--- a/tests/functional/test_utils.py
+++ b/tests/functional/test_utils.py
@@ -36,3 +36,37 @@ def test_basic(tmp_path):
     assert Path(tmp_path / 'src/rose-suite.conf').read_text() == (
         Path(tmp_path / 'dest/rose-suite.conf').read_text()
     )
+
+
+def test_CYLC_SYMLINKS(monkeypatch, tmp_path, cylc_validate_cli):
+    """We reload the global config after exporting env variables."""
+    # Setup global config:
+    global_conf = """#!jinja2
+        {% from "cylc.flow" import LOG %}
+        {% set cylc_symlinks = environ.get('CYLC_SYMLINKS', None) %}
+        {% do LOG.critical(cylc_symlinks) %}
+    """
+    conf_path = tmp_path / 'conf'
+    conf_path.mkdir()
+    monkeypatch.setenv('CYLC_CONF_PATH', conf_path)
+
+    # Setup workflow config:
+    (conf_path / 'global.cylc').write_text(global_conf)
+    (tmp_path / 'rose-suite.conf').write_text(
+        '[env]\nCYLC_SYMLINKS="Foo"\n')
+    (tmp_path / 'flow.cylc').write_text("""
+        [scheduling]
+            initial cycle point = now
+            [[graph]]
+                R1 = x
+        [runtime]
+            [[x]]
+    """)
+
+    # Validate the config:
+    output = cylc_validate_cli(tmp_path)
+    assert output.ret == 0
+
+    # CYLC_SYMLINKS == None the first time the global.cylc
+    # is loaded and "Foo" the second time.
+    assert output.logging == 'None\n"Foo"'