From 58a3b56e3780d8e3822d7d21005ea1f5bae81206 Mon Sep 17 00:00:00 2001
From: Emmanuel Viennet <emmanuel.viennet@gmail.com>
Date: Mon, 5 Aug 2024 15:42:59 +0200
Subject: [PATCH] WIP: Celery

---
 app/__init__.py       | 26 ++++++++++++++++++++++++-
 app/views/scodoc.py   | 21 +++++++++++++++++++++
 config.py             |  8 ++++++++
 requirements-3.11.txt | 10 ++++++++++
 tasks.py              | 44 +++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 108 insertions(+), 1 deletion(-)
 create mode 100644 tasks.py

diff --git a/app/__init__.py b/app/__init__.py
index 97690884..fabcc989 100755
--- a/app/__init__.py
+++ b/app/__init__.py
@@ -15,6 +15,7 @@ from logging.handlers import SMTPHandler, WatchedFileHandler
 from threading import Thread
 import warnings
 
+from celery import Celery, Task
 from flask import current_app, g, request
 from flask import Flask
 from flask import abort, flash, has_request_context
@@ -270,13 +271,36 @@ class ReverseProxied(object):
         return self.app(environ, start_response)
 
 
-def create_app(config_class=DevConfig):
+def celery_init_app(app: Flask) -> Celery:
+    """Initialize Celery.
+    See https://flask.palletsprojects.com/en/latest/patterns/celery
+    """
+
+    class FlaskTask(Task):
+        "Task in Flask context"
+
+        def __call__(self, *args: object, **kwargs: object) -> object:
+            with app.app_context():
+                return self.run(*args, **kwargs)
+
+    celery_app = Celery(app.name, task_cls=FlaskTask)
+    celery_app.config_from_object(app.config["CELERY"])
+    celery_app.set_default()
+    app.extensions["celery"] = celery_app
+    return celery_app
+
+
+def create_app(config_class=DevConfig) -> Flask:
+    """Create Flask application"""
     app = Flask(__name__, static_url_path="/ScoDoc/static", static_folder="static")
     app.config.from_object(config_class)
     from app.auth import cas
 
     CAS(app, url_prefix="/cas", configuration_function=cas.set_cas_configuration)
     app.wsgi_app = ReverseProxied(app.wsgi_app)
+    # --- Celery
+    celery_init_app(app)
+    # --- JSON
     app_json = FlaskJSON(app)
 
     @app_json.encoder
diff --git a/app/views/scodoc.py b/app/views/scodoc.py
index f7893132..0a6ee9e3 100644
--- a/app/views/scodoc.py
+++ b/app/views/scodoc.py
@@ -746,3 +746,24 @@ def ue_colors_css(formation_id: int, semestre_idx: int):
 #     current_app.logger.critical(f"testlog message CRITICAL")
 #     raise SyntaxError("une erreur de syntaxe")
 #     return "testlog completed at " + str(time.time())
+
+
+@bp.route("/example_task_run/<int:duration>")
+def run_example_task(duration: int):
+    """Lance tâche de fond
+    http://deb12.viennet.net:5000/example_task_run/60
+    """
+    from tasks import sco_example_task
+
+    task = sco_example_task.apply_async(duration=duration)
+    return redirect(url_for("scodoc.example_task_status", task_id=task.id))
+
+
+@bp.route("/example_task_status/<task_id>")
+def example_task_status(task_id):
+    """Status tâche de fond"""
+    from tasks import sco_example_task
+
+    task = sco_example_task.AsyncResult(task_id)
+
+    return f"Task {task_id}: state={task.state} {task.info.get('current', '?')} / {task.info.get('total_duration', '?')} ({task.info.get('status', '?')})"
diff --git a/config.py b/config.py
index d98e9513..23d03b15 100755
--- a/config.py
+++ b/config.py
@@ -43,6 +43,14 @@ class Config:
     JSON_USE_ENCODE_METHODS = True
     JSON_DATETIME_FORMAT = "%Y-%m-%dT%H:%M:%S%z"  # "%Y-%m-%dT%H:%M:%S"
 
+    # Celery
+    CELERY = {
+        "broker_connection_retry_on_startup": True,
+        "broker_url": os.environ.get("CELERY_BROKER_URL") or "redis://localhost:6379/0",
+        "result_backend": os.environ.get("CELERY_RESULT_BACKEND")
+        or "redis://localhost:6379/0",
+    }
+
 
 class ProdConfig(Config):
     "mode production, normalement derrière nginx/gunicorn"
diff --git a/requirements-3.11.txt b/requirements-3.11.txt
index 825c1635..a684f203 100644
--- a/requirements-3.11.txt
+++ b/requirements-3.11.txt
@@ -1,17 +1,23 @@
 alembic==1.13.2
+amqp==5.2.0
 astroid==3.2.4
 async-timeout==4.0.3
 attrs==23.2.0
 Babel==2.15.0
+billiard==4.2.0
 black==24.4.2
 blinker==1.8.2
 Brotli==1.1.0
 cachelib==0.9.0
+celery==5.4.0
 certifi==2024.7.4
 cffi==1.16.0
 chardet==5.2.0
 charset-normalizer==3.3.2
 click==8.1.7
+click-didyoumean==0.3.1
+click-plugins==1.1.1
+click-repl==0.3.0
 cracklib==2.9.6
 cryptography==43.0.0
 cssselect2==0.7.0
@@ -48,6 +54,7 @@ iniconfig==2.0.0
 isort==5.13.2
 itsdangerous==2.2.0
 Jinja2==3.1.4
+kombu==5.3.7
 lazy-object-proxy==1.10.0
 lxml==5.2.2
 Mako==1.3.5
@@ -64,6 +71,7 @@ pathspec==0.12.1
 pillow==10.4.0
 platformdirs==4.2.2
 pluggy==1.5.0
+prompt_toolkit==3.0.47
 psycopg2==2.9.9
 puremagic==1.26
 py==1.11.0
@@ -105,7 +113,9 @@ tuna==0.5.11
 typing_extensions==4.12.2
 tzdata==2024.1
 urllib3==2.2.2
+vine==5.1.0
 visitor==0.1.3
+wcwidth==0.2.13
 weasyprint==62.3
 webencodings==0.5.1
 Werkzeug==3.0.3
diff --git a/tasks.py b/tasks.py
new file mode 100644
index 00000000..0f245b6f
--- /dev/null
+++ b/tasks.py
@@ -0,0 +1,44 @@
+"""Essai Celery"""
+
+import time
+from celery import shared_task
+
+from app import create_app
+
+flask_app = create_app()  # -Line 2
+celery_app = flask_app.extensions["celery"]  # -Line 3
+
+
+@shared_task(ignore_result=False)  # -Line 4
+def long_running_task(iterations) -> int:  # -Line 5
+    result = 0
+    for i in range(iterations):
+        result += i
+        time.sleep(2)
+    return result  # -Line 6
+
+
+@shared_task(ignore_result=False, bind=True)
+def sco_example_task(self, duration: int = 10):
+    """Example task to run in background.
+
+    Args:
+        duration (int): duration in seconds
+
+    Returns:
+        int: result
+    """
+    for i in range(duration):
+        self.update_state(
+            state="PROGRESS",
+            meta={"current": i, "total_duration": duration, "status": "running"},
+        )
+        time.sleep(1)
+
+    return {
+        "current": 100,
+        "total": 100,
+        "status": "Task completed!",
+        "total_duration": duration,
+        "result": duration,
+    }