Fix Validation using old tvars fails for Cylc 7 workflows

CHANGES.md

@@ -11,6 +11,15 @@ updated. Only the first match gets replaced, so it's fine to leave the old
 ones in. -->
 
 -------------------------------------------------------------------------------
+
+## __cylc-8.1.1 (<span actions:bind='release-date'>Coming Soon</span>)__
+
+### Fixes
+
+[#5313](https://github.com/cylc/cylc-flow/pull/5313) - Fix a bug
+causing Cylc to be unable to parse previously played Cylc 7 workflows.
+
+
 ## __cylc-8.1.0 (<span actions:bind='release-date'>Released 2023-01-16</span>)__
 
 ### Breaking Changes

cylc/flow/scripts/validate_reinstall.py

@@ -47,6 +47,14 @@
 
 from cylc.flow import LOG
 from cylc.flow.exceptions import ServiceFileError
+from cylc.flow.id_cli import parse_id
+from cylc.flow.option_parsers import (
+    WORKFLOW_ID_ARG_DOC,
+    CylcOptionParser as COP,
+    combine_options,
+    log_subcommand,
+    cleanup_sysargv
+)
 from cylc.flow.scheduler_cli import PLAY_OPTIONS, scheduler_cli
 from cylc.flow.scripts.validate import (
     VALIDATE_OPTIONS,
@@ -58,14 +66,6 @@
 from cylc.flow.scripts.reload import (
     reload_cli as cylc_reload
 )
-from cylc.flow.option_parsers import (
-    WORKFLOW_ID_ARG_DOC,
-    CylcOptionParser as COP,
-    combine_options,
-    log_subcommand,
-    cleanup_sysargv
-)
-from cylc.flow.id_cli import parse_id
 from cylc.flow.terminal import cli_function
 from cylc.flow.workflow_files import detect_old_contact_file
 
@@ -135,10 +135,16 @@ def vro_cli(parser: COP, options: 'Values', workflow_id: str):
     try:
         detect_old_contact_file(workflow_id)
     except ServiceFileError:
-        # Workflow is definately running:
+        # Workflow is definitely running:
         workflow_running = True
+    except Exception:
+        LOG.critical(
+            'Cannot tell if the workflow is running'
+            '\nNote, Cylc 8 cannot restart Cylc 7 workflows.'
+        )
+        raise
     else:
-        # Workflow is definately stopped:
+        # Workflow is definitely stopped:
         workflow_running = False
 
     # options.tvars and tvars_file are _only_ valid when playing a stopped

cylc/flow/templatevars.py

@@ -20,17 +20,18 @@
 from typing import Any, Dict
 
 from cylc.flow.exceptions import InputError
-
-
 from cylc.flow.rundb import CylcWorkflowDAO
+from cylc.flow.workflow_db_mgr import WorkflowDatabaseManager
 
 
 def get_template_vars_from_db(run_dir):
     """Get template vars stored in a workflow run database.
     """
     template_vars = {}
     if (run_dir / 'log/db').exists():
-        dao = CylcWorkflowDAO(str(run_dir / 'log/db'))
+        WorkflowDatabaseManager(
+            str(run_dir / 'log')).check_workflow_db_compatibility()
+        dao = CylcWorkflowDAO(str(run_dir / 'log/db'), is_public=True)
         dao.select_workflow_template_vars(
             lambda _, row: template_vars.__setitem__(row[0], eval_var(row[1]))
         )

tests/unit/parsec/test_fileparse.py

@@ -22,6 +22,7 @@
 import sqlite3
 from types import SimpleNamespace
 
+from cylc.flow import __version__ as cylc_version
 from cylc.flow.parsec.exceptions import (
     FileParseError,
     IncludeFileNotFoundError,
@@ -627,6 +628,14 @@ def _inner(create_srclink=True):
             "INSERT INTO workflow_template_vars VALUES"
             "    ('Marius', '\"Consul\"')"
         )
+        conn.execute(
+            "CREATE TABLE workflow_params"
+            "(key TEXT, value TEXT, PRIMARY KEY(key)) ;"
+        )
+        conn.execute(
+            "INSERT INTO workflow_params VALUES"
+            f"    ('cylc_version', '{cylc_version}')"
+        )
         conn.commit()
         conn.close()
 
@@ -658,7 +667,7 @@ def _inner(create_srclink=True):
         ),
     ]
 )
-def test__prepend_old_templatevars2(_mock_old_template_vars_db, expect, tvars):
+def test__prepend_old_templatevars(_mock_old_template_vars_db, expect, tvars):
     # Create a target for a source symlink
     result = _prepend_old_templatevars(
         _mock_old_template_vars_db(), tvars)

tests/unit/test_templatevars.py

@@ -22,6 +22,7 @@
 from types import SimpleNamespace
 
 
+from cylc.flow import __version__ as cylc_version
 from cylc.flow.exceptions import PluginError
 from cylc.flow.templatevars import (
     get_template_vars_from_db,
@@ -125,6 +126,21 @@ def _setup_db(tmp_path_factory):
             )
         '''
     )
+    conn.execute(
+        r'''
+            CREATE TABLE workflow_params (
+                key,
+                value
+            )
+        '''
+    )
+    conn.execute(
+        rf'''
+            INSERT INTO workflow_params
+            VALUES
+                ("cylc_version", "{cylc_version}")
+        '''
+    )
     conn.execute(
         r'''
             INSERT INTO workflow_template_vars
@@ -153,3 +169,10 @@ def test_get_old_tvars(key, expect, _setup_db):
     """It can extract a variety of items from a workflow database.
     """
     assert _setup_db[key] == expect
+
+
+def test_dont_get_old_tvars_back_compat(tmp_path):
+    """It won't even try to extract workflow_template_vars in compat mode.
+    """
+    tmp_path.touch('suite.rc')
+    assert get_template_vars_from_db(tmp_path) == {}