feat: async investigate_fragment task; celery results backend

ietf/doc/forms.py

@@ -276,6 +276,7 @@ class InvestigateForm(forms.Form):
         ),
         min_length=8,
     )
+    task_id = forms.CharField(required=False, widget=forms.HiddenInput)
 
     def clean_name_fragment(self):
         disallowed_characters = ["%", "/", "\\", "*"]

ietf/doc/tasks.py

@@ -31,6 +31,7 @@
     generate_idnits2_rfcs_obsoleted,
     update_or_create_draft_bibxml_file,
     ensure_draft_bibxml_path_exists,
+    investigate_fragment,
 )
 
 
@@ -119,3 +120,11 @@ def generate_draft_bibxml_files_task(days=7, process_all=False):
             update_or_create_draft_bibxml_file(event.doc, event.rev)
         except Exception as err:
             log.log(f"Error generating bibxml for {event.doc.name}-{event.rev}: {err}")
+
+
+@shared_task(ignore_result=False)
+def investigate_fragment_task(name_fragment: str):
+    return {
+        "name_fragment": name_fragment,
+        "results": investigate_fragment(name_fragment),
+    }

ietf/doc/tests_tasks.py

@@ -20,6 +20,7 @@
     generate_draft_bibxml_files_task,
     generate_idnits2_rfcs_obsoleted_task,
     generate_idnits2_rfc_status_task,
+    investigate_fragment_task,
     notify_expirations_task,
 )
 
@@ -98,6 +99,18 @@ def test_expire_last_calls_task(self, mock_get_expired, mock_expire):
         self.assertEqual(mock_expire.call_args_list[1], mock.call(docs[1]))
         self.assertEqual(mock_expire.call_args_list[2], mock.call(docs[2]))
 
+    def test_investigate_fragment_task(self):
+        investigation_results = object()  # singleton
+        with mock.patch(
+            "ietf.doc.tasks.investigate_fragment", return_value=investigation_results
+        ) as mock_inv:
+            retval = investigate_fragment_task("some fragment")
+        self.assertTrue(mock_inv.called)
+        self.assertEqual(mock_inv.call_args, mock.call("some fragment"))
+        self.assertEqual(
+            retval, {"name_fragment": "some fragment", "results": investigation_results}
+        )
+
 
 class Idnits2SupportTests(TestCase):
     settings_temp_path_overrides = TestCase.settings_temp_path_overrides + ['DERIVED_DIR']

ietf/doc/views_doc.py

@@ -41,10 +41,11 @@
 
 from pathlib import Path
 
+from celery.result import AsyncResult
 from django.core.cache import caches
 from django.core.exceptions import PermissionDenied
 from django.db.models import Max
-from django.http import HttpResponse, Http404, HttpResponseBadRequest
+from django.http import HttpResponse, Http404, HttpResponseBadRequest, JsonResponse
 from django.shortcuts import render, get_object_or_404, redirect
 from django.template.loader import render_to_string
 from django.urls import reverse as urlreverse
@@ -59,8 +60,9 @@
     ConsensusDocEvent, NewRevisionDocEvent, TelechatDocEvent, WriteupDocEvent, IanaExpertDocEvent,
     IESG_BALLOT_ACTIVE_STATES, STATUSCHANGE_RELATIONS, DocumentActionHolder, DocumentAuthor,
     RelatedDocument, RelatedDocHistory)
+from ietf.doc.tasks import investigate_fragment_task
 from ietf.doc.utils import (augment_events_with_revision,
-    can_adopt_draft, can_unadopt_draft, get_chartering_type, get_tags_for_stream_id, investigate_fragment,
+    can_adopt_draft, can_unadopt_draft, get_chartering_type, get_tags_for_stream_id,
     needed_ballot_positions, nice_consensus, update_telechat, has_same_ballot,
     get_initial_notify, make_notify_changed_event, make_rev_history, default_consensus,
     add_events_message_info, get_unicode_document_content,
@@ -2275,16 +2277,67 @@ def idnits2_state(request, name, rev=None):
         content_type="text/plain;charset=utf-8",
     )
 
+
 @role_required("Secretariat")
 def investigate(request):
+    """Investigate a fragment
+
+    A plain GET with no querystring returns the UI page.
+
+    POST with the task_id field empty starts an async task and returns a JSON response with
+    the ID needed to monitor the task for results.
+
+    GET with a querystring parameter "id" will poll the status of the async task and return "ready"
+    or "notready".
+
+    POST with the task_id field set to the id of a "ready" task will return its results or an error
+    if the task failed or the id is invalid (expired, never exited, etc).
+    """
     results = None
+    # Start an investigation or retrieve a result on a POST
     if request.method == "POST":
         form = InvestigateForm(request.POST)
         if form.is_valid():
-            name_fragment = form.cleaned_data["name_fragment"]
-            results = investigate_fragment(name_fragment)
+            task_id = form.cleaned_data["task_id"]
+            if task_id:
+                # Ignore the rest of the form and retrieve the result
+                task_result = AsyncResult(task_id)
+                if task_result.successful():
+                    retval = task_result.get()
+                    results = retval["results"]
+                    form.data = form.data.copy()
+                    form.data["name_fragment"] = retval[
+                        "name_fragment"
+                    ]  # ensure consistency
+                    del form.data["task_id"]  # do not request the task result again
+                else:
+                    form.add_error(
+                        None,
+                        "The investigation task failed. Please try again and ask for help if this recurs.",
+                    )
+                # Falls through to the render at the end!
+            else:
+                name_fragment = form.cleaned_data["name_fragment"]
+                task_result = investigate_fragment_task.delay(name_fragment)
+                return JsonResponse({"id": task_result.id})
     else:
-        form = InvestigateForm()
+        task_id = request.GET.get("id", None)
+        if task_id is not None:
+            # Check status if we got the "id" parameter
+            task_result = AsyncResult(task_id)
+            return JsonResponse(
+                {"status": "ready" if task_result.ready() else "notready"}
+            )
+        else:
+            # Serve up an empty form
+            form = InvestigateForm()
+
+    # If we get here, it is just a plain GET - serve the UI
     return render(
-        request, "doc/investigate.html", context=dict(form=form, results=results)
+        request,
+        "doc/investigate.html",
+        context={
+            "form": form,
+            "results": results,
+        },
     )

ietf/settings.py

@@ -452,6 +452,7 @@ def skip_unreadable_post(record):
     'django_vite',
     'django_bootstrap5',
     'django_celery_beat',
+    'django_celery_results',
     'corsheaders',
     'django_markup',
     'oidc_provider',
@@ -1226,7 +1227,9 @@ def skip_unreadable_post(record):
 # https://docs.celeryq.dev/en/stable/userguide/tasks.html#rpc-result-backend-rabbitmq-qpid
 # Results can be retrieved only once and only by the caller of the task. Results will be
 # lost if the message broker restarts.
-CELERY_RESULT_BACKEND = 'rpc://'  # sends a msg via the msg broker
+CELERY_RESULT_BACKEND = 'django-cache'  # use a Django cache for results
+CELERY_CACHE_BACKEND = 'celery-results'  # which Django cache to use
+CELERY_RESULT_EXPIRES = datetime.timedelta(minutes=5)  # how long are results valid? (Default is 1 day)
 CELERY_TASK_IGNORE_RESULT = True  # ignore results unless specifically enabled for a task
 
 # Meetecho API setup: Uncomment this and provide real credentials to enable
@@ -1309,6 +1312,11 @@ def skip_unreadable_post(record):
                     "MAX_ENTRIES": 5000,
                 },
             },
+            "celery-results": {
+                "BACKEND": "django.core.cache.backends.memcached.PyMemcacheCache",
+                "LOCATION": f"{MEMCACHED_HOST}:{MEMCACHED_PORT}",
+                "KEY_PREFIX": "ietf:celery",
+            },
         }
     else:
         CACHES = {
@@ -1347,6 +1355,11 @@ def skip_unreadable_post(record):
                     "MAX_ENTRIES": 5000,
                 },
             },
+            "celery-results": {
+                "BACKEND": "django.core.cache.backends.memcached.PyMemcacheCache",
+                "LOCATION": "app:11211",
+                "KEY_PREFIX": "ietf:celery",
+            },
         }
 
 PUBLISH_IPR_STATES = ['posted', 'removed', 'removed_objfalse']

ietf/static/js/investigate.js

@@ -0,0 +1,53 @@
+// Copyright The IETF Trust 2025, All Rights Reserved
+document.addEventListener('DOMContentLoaded', () => {
+    const investigateForm = document.forms['investigate']
+    investigateForm.addEventListener('submit', (event) => {
+        // Intercept submission unless we've filled in the task_id field
+        if (!investigateForm.elements['id_task_id'].value) {
+            event.preventDefault()
+            runInvestigation()
+        }
+    })
+
+    const runInvestigation = async () => {
+        // Submit the request
+        const response = await fetch('', {
+            method: investigateForm.method, body: new FormData(investigateForm)
+        })
+        if (!response.ok) {
+            loadResultsFromTask('bogus-task-id') // bad task id will generate an error from Django
+        }
+        const taskId = (await response.json()).id
+        // Poll for completion of the investigation up to 18*10 = 180 seconds 
+        waitForResults(taskId, 18)
+    }
+
+    const waitForResults = async (taskId, retries) => {
+        // indicate that investigation is in progress
+        document.getElementById('spinner').classList.remove('d-none')
+        document.getElementById('investigate-button').disabled = true
+        investigateForm.elements['id_name_fragment'].disabled = true
+
+        const response = await fetch('?' + new URLSearchParams({ id: taskId }))
+        if (!response.ok) {
+            loadResultsFromTask('bogus-task-id') // bad task id will generate an error from Django
+        }
+        const result = await response.json()
+        if (result.status !== 'ready' && retries > 0) {
+            // 10 seconds per retry
+            setTimeout(waitForResults, 10000, taskId, retries - 1)
+        } else {
+            /* Either the response is ready or we timed out waiting. In either case, submit
+               the task_id via POST and let Django display an error if it's not ready. Before
+               submitting, re-enable the form fields so the POST is valid. Other in-progress
+               indicators will be reset when the POST response is loaded. */
+            loadResultsFromTask(taskId)
+        }
+    }
+
+    const loadResultsFromTask = (taskId) => {
+        investigateForm.elements['id_name_fragment'].disabled = false
+        investigateForm.elements['id_task_id'].value = taskId
+        investigateForm.submit()
+    }
+})