Make a new standard template variable "CYLC_SOURCE_DIRECTORY"

available to users.

Author: wxtim

changes.d/6944.feat.md

@@ -0,0 +1 @@
+Make WORKFLOW_SOURCE_DIRECTORY available as a template variable.

cylc/flow/parsec/fileparse.py

@@ -471,6 +471,11 @@ def read_and_proc(
     template_vars = merge_template_vars(template_vars, extra_vars)
     template_vars['CYLC_TEMPLATE_VARS'] = template_vars
 
+    # Add CYLC_SOURCE_DIRECTORY to template variables.
+    sourcepath = get_workflow_source_dir(Path(fpath).parent)[1]
+    template_vars['CYLC_SOURCE_DIRECTORY'] = (
+        sourcepath.readlink() if sourcepath else Path(fpath).parent)
+
     # Fail if templating_detected ≠ hashbang
     process_with = hashbang_and_plugin_templating_clash(
         extra_vars[TEMPLATING_DETECTED], flines

tests/functional/cylc-combination-scripts/10-CYLC_SOURCE_DIRECTORY.t

@@ -0,0 +1,89 @@
+#!/usr/bin/env bash
+# THIS FILE IS PART OF THE CYLC WORKFLOW ENGINE.
+# Copyright (C) NIWA & British Crown (Met Office) & Contributors.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+#------------------------------------------------------------------------------
+# Test `cylc vip` (Validate Install Play)
+
+. "$(dirname "$0")/test_header"
+
+CYLC_ROSE=$(python -c """
+try:
+    import cylc.rose
+    print('true')
+except:
+    print('false')
+""")
+
+set_test_number 7
+
+WORKFLOW_NAME="cylctb-x$(< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c6)"
+
+cat > flow.cylc <<__HERE__
+#!jinja2
+# TEST: {{ CYLC_SOURCE_DIRECTORY }}
+[scheduler]
+    allow implicit tasks = true
+[scheduling]
+    [[graph]]
+        R1 = foo
+__HERE__
+
+# It starts playing:
+run_ok "${TEST_NAME_BASE}-vip" \
+    cylc vip \
+        --pause \
+        --no-run-name \
+        --workflow-name ${WORKFLOW_NAME}
+
+# It can get CYLC_SOURCE_DIRECTORY
+grep_ok "$PWD" "${RUN_DIR}/${WORKFLOW_NAME}/log/config/flow-processed.cylc"
+
+# It can be updated with Cylc VR
+echo "[meta]" >> flow.cylc
+run_ok "${TEST_NAME_BASE}-vr" \
+    cylc vr ${WORKFLOW_NAME}
+poll_grep "meta" "${RUN_DIR}/${WORKFLOW_NAME}/log/config/flow-processed.cylc"
+
+# It can get CYLC_SOURCE_DIRECTORY
+grep_ok "$PWD" "${RUN_DIR}/${WORKFLOW_NAME}/log/config/flow-processed.cylc"
+
+purge "${WORKFLOW_NAME}"
+
+# If we have Cylc Rose installed, check that Rose Stem workflows
+# Also have access to WORKFLOW_SOURCE_DIR
+if [[ "$CYLC_ROSE" == 'false' ]]; then
+    skip 3 "Install cylc-rose to run this test."
+    exit 0
+else
+    WORKFLOW_NAME="cylctb-x$(< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c6)"
+    mkdir rose-stem
+    mv flow.cylc rose-stem/flow.cylc
+    echo "ROSE_STEM_VERSION=1" > rose-stem/rose-suite.conf
+fi
+
+run_ok "${TEST_NAME_BASE}-rose-stem" \
+    rose stem \
+        --source=${WORKFLOW_NAME}=${PWD} \
+        --workflow-name ${WORKFLOW_NAME} \
+        --no-run-name
+run_ok "${TEST_NAME_BASE}-run-rose-stem" \
+    cylc play "${WORKFLOW_NAME}" --no-detach
+grep_ok "$PWD" "${RUN_DIR}/${WORKFLOW_NAME}/log/config/flow-processed.cylc"
+
+purge "${WORKFLOW_NAME}"
+
+exit 0

tests/integration/test_config.py

@@ -31,6 +31,7 @@
     XtriggerConfigError,
 )
 from cylc.flow.parsec.exceptions import ListValueError
+from cylc.flow.parsec.fileparse import read_and_proc
 from cylc.flow.pathutil import get_workflow_run_pub_db_path
 
 Fixture = Any
@@ -671,3 +672,45 @@ async def test_invalid_starttask(one_conf, flow, scheduler, start):
     with pytest.raises(InputError, match='a///b'):
         async with start(schd):
             pass
+
+
+async def test_CYLC_SOURCE_DIRECTORY_correctly_set(
+    tmp_path, install, run_dir):
+    """CYLC_SOURCE_DIRECTORY is set correctly:
+
+    * In source dir
+    * In installed dir (Not testing different permutations of installed
+      dir as these are covered by testing of `get_workflow_source_dir`)
+    * Created directly in the run dir.
+
+    """
+    def mock_cylc_view(target):
+        """Run config through read_and_proc (~= cylc view --process)
+        """
+        return read_and_proc(
+            target,
+            viewcfg={
+                'mark': False,
+                'single': False,
+                'label': False,
+                'jinja2': True,
+                'contin': True,
+                'inline': True,
+            },
+        )
+
+    # Setup a source directory:
+    (tmp_path / 'flow.cylc').write_text(
+        '#!jinja2\n{{ CYLC_SOURCE_DIRECTORY }}'
+    )
+
+    # Check that the CYLC_SRC_DIRECTORY
+    # points to the source directory (tmp_path):
+    processed = mock_cylc_view(tmp_path / 'flow.cylc')
+    assert processed[0] == str(tmp_path)
+
+    # After installation the CYLC_SOURCE_DIRECTORY
+    # *still* points back to tmp_path:
+    wid = await install(tmp_path)
+    processed = mock_cylc_view(run_dir / wid / 'flow.cylc')
+    assert processed[0] == str(tmp_path)