vr: restart the workflow with no changes according to user prompt

changes.d/6261.feat.md

@@ -0,0 +1 @@
+Allow a workflow to be restarted by `cylc vr` even if there are no changes to reinstall.

cylc/flow/scripts/validate_reinstall.py

@@ -46,6 +46,8 @@
 if TYPE_CHECKING:
     from optparse import Values
 
+from ansimarkup import parse as cparse
+
 from cylc.flow import LOG
 from cylc.flow.exceptions import (
     ContactFileExists,
@@ -74,7 +76,7 @@
 from cylc.flow.scripts.reload import (
     run as cylc_reload
 )
-from cylc.flow.terminal import cli_function
+from cylc.flow.terminal import cli_function, is_terminal
 from cylc.flow.workflow_files import detect_old_contact_file
 
 CYLC_ROSE_OPTIONS = COP.get_cylc_rose_options()
@@ -87,6 +89,10 @@
     modify={'cylc-rose': 'validate, install'}
 )
 
+_input = input  # to enable testing
+
+NO_CHANGES_STR = 'No changes to reinstall'
+
 
 def get_option_parser() -> COP:
     parser = COP(
@@ -189,34 +195,54 @@
     # Force on the against_source option:
     options.against_source = True
 
-    # Run cylc validate
+    # Run "cylc validate"
     log_subcommand('validate --against-source', workflow_id)
     await cylc_validate(parser, options, workflow_id)
 
     # Unset options that do not apply after validation:
     delattr(options, 'against_source')
     delattr(options, 'is_validate')
 
+    # Run "cylc reinstall"
     log_subcommand('reinstall', workflow_id)
     reinstall_ok = await cylc_reinstall(
-        options, workflow_id,
+        options,
+        workflow_id,
         [],
         print_reload_tip=False
     )
     if not reinstall_ok:
-        LOG.warning(
-            'No changes to source: No reinstall or'
-            f' {"reload" if workflow_running else "play"} required.'
-        )
-        return False
-
-    # Run reload if workflow is running or paused:
+        if (
+            not workflow_running
+            and is_terminal()
+            and not options.skip_interactive
+        ):
+            # there are no changes to install but the workflow isn't running
+            # => ask the user if they want to restart it anyway
+            usr = None
+            while usr not in ['y', 'n']:
+                LOG.warning(NO_CHANGES_STR)
+                usr = _input(
+                    cparse('<bold>Restart anyway?</bold> [y/n]: ')
+                ).lower()
+            if usr == 'n':
+                return False
+        else:
+            # the are no changes to install and the workflow is running
+            # => there is nothing for us to do here
+            LOG.warning(
+                f'{NO_CHANGES_STR}: No reinstall or'
+                f' {"reload" if workflow_running else "play"} required.'
+            )
+            return False
+
+    # Run "cylc reload" (if workflow is running or paused)
     if workflow_running:
         log_subcommand('reload', workflow_id)
         await cylc_reload(options, workflow_id)
         return True
 
-    # run play anyway, to play a stopped workflow:
+    # Run "cylc play" (if workflow is stopped)
     else:
         set_timestamps(LOG, options.log_timestamp)
         cleanup_sysargv(

tests/integration/scripts/__init__.py

@@ -0,0 +1,15 @@
+# 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/>.

tests/integration/scripts/conftest.py

@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+
+# 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/>.
+
+from types import SimpleNamespace
+from uuid import uuid1
+
+import pytest
+
+from cylc.flow.workflow_files import WorkflowFiles
+
+from ..utils.flow_writer import flow_config_str
+
+
+@pytest.fixture
+def one_src(tmp_path, one_conf):
+    src_dir = tmp_path
+    (src_dir / 'flow.cylc').write_text(flow_config_str(one_conf))
+    (src_dir / 'rose-suite.conf').touch()
+    return SimpleNamespace(path=src_dir)
+
+
+@pytest.fixture
+def one_run(one_src, test_dir, run_dir):
+    w_run_dir = test_dir / str(uuid1())
+    w_run_dir.mkdir()
+    (w_run_dir / 'flow.cylc').write_text(
+        (one_src.path / 'flow.cylc').read_text()
+    )
+    (w_run_dir / 'rose-suite.conf').write_text(
+        (one_src.path / 'rose-suite.conf').read_text()
+    )
+    install_dir = (w_run_dir / WorkflowFiles.Install.DIRNAME)
+    install_dir.mkdir(parents=True)
+    (install_dir / WorkflowFiles.Install.SOURCE).symlink_to(
+        one_src.path,
+        target_is_directory=True,
+    )
+    return SimpleNamespace(
+        path=w_run_dir,
+        id=str(w_run_dir.relative_to(run_dir)),
+    )

tests/integration/test_reinstall.py → tests/integration/scripts/test_reinstall.py

@@ -19,8 +19,6 @@
 import asyncio
 from contextlib import asynccontextmanager
 from pathlib import Path
-from types import SimpleNamespace
-from uuid import uuid1
 
 import pytest
 
@@ -39,7 +37,7 @@
     WorkflowFiles,
 )
 
-from .utils.entry_points import EntryPointWrapper
+from ..utils.entry_points import EntryPointWrapper
 
 ReInstallOptions = Options(reinstall_gop())
 
@@ -66,32 +64,6 @@ def non_interactive(monkeypatch):
     )
 
 
-@pytest.fixture
-def one_src(tmp_path):
-    src_dir = tmp_path
-    (src_dir / 'flow.cylc').touch()
-    (src_dir / 'rose-suite.conf').touch()
-    return SimpleNamespace(path=src_dir)
-
-
-@pytest.fixture
-def one_run(one_src, test_dir, run_dir):
-    w_run_dir = test_dir / str(uuid1())
-    w_run_dir.mkdir()
-    (w_run_dir / 'flow.cylc').touch()
-    (w_run_dir / 'rose-suite.conf').touch()
-    install_dir = (w_run_dir / WorkflowFiles.Install.DIRNAME)
-    install_dir.mkdir(parents=True)
-    (install_dir / WorkflowFiles.Install.SOURCE).symlink_to(
-        one_src.path,
-        target_is_directory=True,
-    )
-    return SimpleNamespace(
-        path=w_run_dir,
-        id=str(w_run_dir.relative_to(run_dir)),
-    )
-
-
 async def test_rejects_random_workflows(one, one_run):
     """It should only work with workflows installed by cylc install."""
     with pytest.raises(WorkflowFilesError) as exc_ctx:

tests/integration/scripts/test_validate_reinstall.py

@@ -0,0 +1,95 @@
+#!/usr/bin/env python3
+
+# 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/>.
+
+from cylc.flow.option_parsers import Options
+from cylc.flow.scripts.validate_reinstall import (
+    get_option_parser as vr_gop,
+    vr_cli,
+)
+
+ValidateReinstallOptions = Options(vr_gop())
+
+
+async def test_prompt_for_running_workflow_with_no_changes(
+    monkeypatch,
+    caplog,
+    capsys,
+    log_filter,
+    one_run,
+    capcall,
+):
+    """It should reinstall and restart the workflow with no changes.
+
+    See: https://github.com/cylc/cylc-flow/issues/6261
+
+    We hope to get users into the habit of "cylc vip" to create a new run,
+    and "cylc vr" to contine an old one (picking up any new changes in the
+    process).
+
+    This works fine, unless there are no changes to reinstall, in which case
+    the "cylc vr" command exits (nothing to do).
+
+    The "nothing to reinstall" situation can be interpreted two ways:
+    1. Unexpected error, the user expected there to be something to reinstall,
+       but there wasn't. E.g, they forgot to press save.
+    2. Unexpected annoyance, I wanted to restart the workflow, just do it.
+
+    To handle this we explain that there are no changes to reinstall and
+    prompt the user to see if they want to press save or restart the workflow.
+    """
+    # disable the clean_sysargv logic (this interferes with other tests)
+    cleanup_sysargv_calls = capcall(
+        'cylc.flow.scripts.validate_reinstall.cleanup_sysargv'
+    )
+
+    # answer "y" to all prompts
+    def _input(prompt):
+        print(prompt)
+        return 'y'
+
+    monkeypatch.setattr(
+        'cylc.flow.scripts.validate_reinstall._input',
+        _input,
+    )
+
+    # make it look like we are running this command in a terminal
+    monkeypatch.setattr(
+        'cylc.flow.scripts.validate_reinstall.is_terminal',
+        lambda: True
+    )
+    monkeypatch.setattr(
+        'cylc.flow.scripts.reinstall.is_terminal',
+        lambda: True
+    )
+
+    # attempt to restart it with "cylc vr"
+    ret = await vr_cli(
+        vr_gop(), ValidateReinstallOptions(), one_run.id
+    )
+    # the workflow should reinstall
+    assert ret
+
+    # the user should have been warned that there were no changes to reinstall
+    assert log_filter(caplog, contains='No changes to reinstall')
+
+    # they should have been presented with a prompt
+    # (to which we have hardcoded the response "y")
+    assert 'Restart anyway?' in capsys.readouterr()[0]
+
+    # the workflow should have restarted
+    assert len(cleanup_sysargv_calls) == 1