From f2fb2b640222e49ed4046db0005863f8c0732e86 Mon Sep 17 00:00:00 2001
From: Arie Peterson <arie@greenhost.nl>
Date: Tue, 24 Jan 2023 16:47:44 +0100
Subject: [PATCH] Do not run initialization code concurrently
---
backend/app.py | 52 ++++++++++++++++++++++++----------------
backend/requirements.txt | 1 +
2 files changed, 32 insertions(+), 21 deletions(-)
diff --git a/backend/app.py b/backend/app.py
index ec18e9b6..62217372 100644
--- a/backend/app.py
+++ b/backend/app.py
@@ -3,6 +3,7 @@ from flask_cors import CORS
from flask_jwt_extended import JWTManager
import flask_migrate
from jsonschema.exceptions import ValidationError
+from NamedAtomicLock import NamedAtomicLock
from werkzeug.exceptions import BadRequest
# These imports are required
@@ -68,27 +69,36 @@ app.logger.info("Starting dashboard backend.")
cors = CORS(app)
db.init_app(app)
-with app.app_context():
- # We have reset the alembic migration history at Stackspin version 2.2.
- # This checks whether we need to prepare the database to follow that
- # change.
- migration_reset.reset()
-flask_migrate.Migrate(app, db)
-try:
- with app.app_context():
- flask_migrate.upgrade()
-except Exception as e:
- app.logger.info(f"upgrade failed: {type(e)}: {e}")
- sys.exit(2)
-
-# We need this app context in order to talk the database, which is managed by
-# flask-sqlalchemy, which assumes a flask app context.
-with app.app_context():
- # Load the list of apps from a configmap and store any missing ones in the
- # database.
- cluster_config.populate_apps()
- # Same for the list of oauthclients.
- cluster_config.populate_oauthclients()
+
+# We'll now perform some initialization routines. Because these have to be done
+# once at startup, not for every gunicorn worker, we take a machine-wide lock
+# for this.
+init_lock = NamedAtomicLock('dashboard_init')
+if init_lock.acquire():
+ try:
+ with app.app_context():
+ # We have reset the alembic migration history at Stackspin version 2.2.
+ # This checks whether we need to prepare the database to follow that
+ # change.
+ migration_reset.reset()
+ flask_migrate.Migrate(app, db)
+ try:
+ with app.app_context():
+ flask_migrate.upgrade()
+ except Exception as e:
+ app.logger.info(f"upgrade failed: {type(e)}: {e}")
+ sys.exit(2)
+
+ # We need this app context in order to talk the database, which is managed by
+ # flask-sqlalchemy, which assumes a flask app context.
+ with app.app_context():
+ # Load the list of apps from a configmap and store any missing ones in the
+ # database.
+ cluster_config.populate_apps()
+ # Same for the list of oauthclients.
+ cluster_config.populate_oauthclients()
+ finally:
+ init_lock.release()
app.register_blueprint(api_v1)
app.register_blueprint(web)
diff --git a/backend/requirements.txt b/backend/requirements.txt
index 9a625388..05715b0e 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -19,6 +19,7 @@ jinja2-base64-filters==0.1.4
kubernetes==24.2.0
MarkupSafe==2.1.1
mypy-extensions==0.4.3
+NamedAtomicLock==1.1.3
oauthlib==3.2.0
pathspec==0.9.0
platformdirs==2.5.1
--
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