Add CYLC_TASK_SHARE_CYCLE_DIR to task script. (cylc#6117)

Add `CYLC_TASK_SHARE_CYCLE_DIR` environment variable

* Create `share/cycle/<cycle>`.
* Expose it to jobs as `CYLC_TASK_SHARE_CYCLE_DIR`

---------

Co-authored-by: Oliver Sanders <[email protected]>
Co-authored-by: Ronnie Dutta <[email protected]>

changes.d/6117.feat.md

@@ -0,0 +1 @@
+Create `workflow/share/cycle/<cycle>` and make it available to jobs as `$CYLC_TASK_SHARE_CYCLE_DIR`.

cylc/flow/etc/job.sh

@@ -95,6 +95,7 @@ cylc__job__main() {
         CYLC_TASK_WORK_DIR_BASE="${CYLC_TASK_CYCLE_POINT}/${CYLC_TASK_NAME}"
     fi
     export CYLC_TASK_WORK_DIR="${CYLC_WORKFLOW_WORK_DIR}/${CYLC_TASK_WORK_DIR_BASE}"
+    export CYLC_TASK_SHARE_CYCLE_DIR="${CYLC_WORKFLOW_SHARE_DIR}/cycle/${CYLC_TASK_CYCLE_POINT}"
     typeset contact="${CYLC_WORKFLOW_RUN_DIR}/.service/contact"
     if [[ -f "${contact}" ]]; then
         # (contact file not present for polled platforms)
@@ -134,7 +135,7 @@ cylc__job__main() {
     export PATH="${CYLC_WORKFLOW_RUN_DIR}/share/bin:${CYLC_WORKFLOW_RUN_DIR}/bin:${PATH}"
     export PYTHONPATH="${CYLC_WORKFLOW_RUN_DIR}/share/lib/python:${CYLC_WORKFLOW_RUN_DIR}/lib/python:${PYTHONPATH:-}"
     # Create share and work directories
-    mkdir -p "${CYLC_WORKFLOW_SHARE_DIR}" || true
+    mkdir -p "${CYLC_TASK_SHARE_CYCLE_DIR}" || true
     mkdir -p "$(dirname "${CYLC_TASK_WORK_DIR}")" || true
     mkdir -p "${CYLC_TASK_WORK_DIR}"
     cd "${CYLC_TASK_WORK_DIR}"

tests/functional/cylc-clean/01-remote.t

@@ -81,6 +81,7 @@ ${TEST_DIR}/${SYM_NAME}/cycle/cylc-run/${CYLC_TEST_REG_BASE}
 |       \`-- ${TEST_NAME_BASE}
 |           \`-- share
 |               \`-- cycle
+|                   \`-- 1
 \`-- leave-me-alone
 ${TEST_DIR}/${SYM_NAME}/job/cylc-run/${CYLC_TEST_REG_BASE}
 \`-- ${FUNCTIONAL_DIR}

tests/functional/jobscript/02-share-cycle-cycle.t

@@ -0,0 +1,31 @@
+#!/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/>.
+
+# Assert that workflow/share/cycle/<cycle> is created and exported.
+
+. "$(dirname "$0")/test_header"
+set_test_number 4
+
+# Setup:
+install_workflow "${TEST_NAME_BASE}" "${TEST_NAME_BASE}"
+run_ok "${TEST_NAME_BASE}.validate" cylc validate "${WORKFLOW_NAME}"
+workflow_run_ok "${TEST_NAME_BASE}.play" cylc play --no-detach "${WORKFLOW_NAME}"
+
+grep_ok "Hello World" "${WORKFLOW_RUN_DIR}/share/cycle/19900211T0000Z/stuff"
+grep_ok "Hello World" "${WORKFLOW_RUN_DIR}/share/cycle/19900212T0000Z/stuff"
+
+purge

tests/functional/jobscript/02-share-cycle-cycle/flow.cylc

@@ -0,0 +1,11 @@
+[scheduling]
+    initial cycle point = 19900211
+    final cycle point = 19900212
+    [[graph]]
+        P1D = task
+
+[runtime]
+    [[task]]
+        script = """
+            echo "Hello World" > "${CYLC_TASK_SHARE_CYCLE_DIR}/stuff"
+        """