Allow local logs for cat-log

CONTRIBUTING.md

@@ -59,6 +59,7 @@ below.
  - Mel Hall
  - Christopher Bennett
  - Mark Dawson
+ - Scott Wales
  <!-- end-shortlog -->
 
 (All contributors are identifiable with email addresses in the git version

cylc/uiserver/app.py

@@ -65,6 +65,7 @@
 from tornado import ioloop
 from tornado.web import RedirectHandler
 from traitlets import (
+    Bool,
     Dict,
     Float,
     Int,
@@ -324,6 +325,13 @@ class CylcUIServer(ExtensionApp):
         ''',
         default_value=1
     )
+    force_remote_logs = Bool(
+        config=True,
+        help='''
+            Always use --force-remote with `cat-log`
+        ''',
+        default_value=True
+    )
 
     @validate('ui_build_dir')
     def _check_ui_build_dir_exists(self, proposed):
@@ -392,6 +400,7 @@ def __init__(self, *args, **kwargs):
             log=self.log,
             executor=self.executor,
             workflows_mgr=self.workflows_mgr,
+            force_remote_logs=self.config.CylcUIServer.force_remote_logs,
         )
 
     def initialize_settings(self):

cylc/uiserver/resolvers.py

@@ -369,7 +369,14 @@ async def enqueue(stream, queue):
             await queue.put(line.decode())
 
     @classmethod
-    async def cat_log(cls, id_: Tokens, log, info, file=None):
+    async def cat_log(
+            cls,
+            id_: Tokens,
+            log,
+            info,
+            force_remote: bool = True,
+            file: Optional[str] = None,
+    ):
         """Calls `cat log`.
 
         Used for log subscriptions.
@@ -378,10 +385,11 @@ async def cat_log(cls, id_: Tokens, log, info, file=None):
             'cylc',
             'cat-log',
             '--mode=tail',
-            '--force-remote',
             '--prepend-path',
             id_.id,
         ]
+        if force_remote:
+            cmd += ['--force-remote']
         if file:
             cmd += ['-f', file]
         log.info(f'$ {" ".join(cmd)}')
@@ -448,15 +456,17 @@ async def cat_log(cls, id_: Tokens, log, info, file=None):
             yield {'connected': False}
 
     @classmethod
-    async def cat_log_files(cls, id_: Tokens):
+    async def cat_log_files(cls, id_: Tokens, force_remote: bool):
         """Calls cat log to get list of available log files.
 
         Note kept separate from the cat_log method above as this is a one off
         query rather than a process held open for subscription.
         This uses the Cylc cat-log interface, list dir mode, forcing remote
         file checking.
         """
-        cmd: List[str] = ['cylc', 'cat-log', '-m', 'l', '-o', id_.id]
+        cmd: List[str] = ['cylc', 'cat-log', '-m', 'l', id_.id]
+        if force_remote:
+            cmd += ['--force-remote']
         proc_job = await asyncio.subprocess.create_subprocess_exec(
             *cmd,
             stdout=asyncio.subprocess.PIPE,
@@ -488,12 +498,14 @@ def __init__(
         log: 'Logger',
         workflows_mgr: 'WorkflowsManager',
         executor,
+        force_remote_logs: bool,
         **kwargs
     ):
         super().__init__(data)
         self.log = log
         self.workflows_mgr = workflows_mgr
         self.executor = executor
+        self.force_remote_logs = force_remote_logs
 
         # Set extra attributes
         for key, value in kwargs.items():
@@ -580,15 +592,19 @@ async def subscription_service(
             ids[0],
             self.log,
             info,
-            file
+            file=file,
+            force_remote=self.force_remote_logs,
         ):
             yield ret
 
     async def query_service(
         self,
         id_: Tokens,
     ):
-        return await Services.cat_log_files(id_)
+        return await Services.cat_log_files(
+            id_,
+            force_remote=self.force_remote_logs
+        )
 
 
 def kill_process_tree(

cylc/uiserver/tests/test_resolvers.py

@@ -1,5 +1,6 @@
 import asyncio
 from async_timeout import timeout
+import io
 import logging
 import pytest
 from unittest import mock
@@ -115,6 +116,75 @@ async def test_cat_log(workflow_run_dir):
     assert actual.rstrip() == expected.rstrip()
 
 
+async def test_cat_log_remote(workflow_run_dir):
+    (id_, log_dir) = workflow_run_dir
+    workflow = Tokens(id_)
+    log = logging.getLogger(CYLC_LOG)
+
+    info = mock.MagicMock()
+    info.root_value = 2
+    # mock the context
+    info.context = {'sub_statuses': {2: "start"}}
+
+    # Mock out the `cylc cat-log` subprocess and the process killer to avoid
+    # side effects
+    with (mock.patch("asyncio.subprocess.create_subprocess_exec") as subp,
+        mock.patch("cylc.uiserver.resolvers.kill_process_tree") as kpt):
+        subp.return_value.returncode = 0
+        subp.return_value.communicate = mock.AsyncMock()
+        subp.return_value.communicate.return_value = (b"", b"")
+
+        async with timeout(10):
+            ret = services.cat_log(workflow, log, info, force_remote=False)
+            async for response in ret:
+                await asyncio.sleep(0)
+
+        subp.assert_called_once()
+        assert subp.call_args[0] == ('cylc','cat-log','--mode=tail','--prepend-path', workflow.id)
+        subp.reset_mock()
+
+        async with timeout(10):
+            ret = services.cat_log(workflow, log, info, force_remote=True)
+            async for response in ret:
+                await asyncio.sleep(0)
+
+        subp.assert_called_once()
+        assert subp.call_args[0] == ('cylc','cat-log','--mode=tail','--prepend-path', workflow.id, '--force-remote')
+
+
+async def test_cat_log_files_remote(workflow_run_dir):
+    (id_, log_dir) = workflow_run_dir
+    workflow = Tokens(id_)
+    log = logging.getLogger(CYLC_LOG)
+
+    info = mock.MagicMock()
+    info.root_value = 2
+    # mock the context
+    info.context = {'sub_statuses': {2: "start"}}
+
+    # Mock out the `cylc cat-log` subprocess and the process killer to avoid
+    # side effects
+    with (mock.patch("asyncio.subprocess.create_subprocess_exec") as subp,
+        mock.patch("cylc.uiserver.resolvers.kill_process_tree") as kpt):
+        subp.return_value.returncode = 0
+        subp.return_value.communicate = mock.AsyncMock()
+        subp.return_value.communicate.return_value = (b"", b"")
+
+        async with timeout(10):
+            ret = await services.cat_log_files(workflow, force_remote=False)
+
+        subp.assert_called_once()
+        assert subp.call_args[0] == ('cylc','cat-log','-m','l', workflow.id)
+        subp.reset_mock()
+
+        async with timeout(10):
+            ret = await services.cat_log_files(workflow, force_remote=True)
+
+        subp.assert_called_once()
+        assert subp.call_args[0] == ('cylc','cat-log','-m','l', workflow.id, '--force-remote')
+        subp.reset_mock()
+
+
 @pytest.mark.parametrize(
     'text, expected',
     [