Flask and neomodel: ModelDefinitionMismatch - flask

Question

I am getting a neomodel.exceptions.ModelDefinitionMismatch while trying to build a simple Flask app connected to the bold port of Neo4J.
import json
from flask import Flask, jsonify, request
from neomodel import StringProperty, StructuredNode, config
class Item(StructuredNode):
__primarykey__ = "name"
name = StringProperty(unique_index=True)
def create_app():
app = Flask(__name__)
config.DATABASE_URL = 'bolt://neo4j:test#db:7687'
#app.route('/', methods=['GET'])
def get_all_items():
return jsonify({'items': [item.name for item in Item.nodes]})
#app.route('/', methods=['POST'])
def create_item():
item = Item()
item.name = json.loads(request.data)['name']
item.save()
return jsonify({'item': item.__dict__})
return app
Doing postrequest works; I can check in the database that the items actually are added! But the get request returns:
neomodel.exceptions.ModelDefinitionMismatch: Node with labels Item does not resolve to any of the known objects
I'm using Python 3.7.0, Flask 1.0.2 and neomodel 3.0.3
update
To give the full problem: I run the application in a Docker container with docker-compose in DEBUG mode.
The Dockerfile:
FROM continuumio/miniconda3
COPY . /app
RUN pip install Flask gunicorn neomodel==3.3.0
EXPOSE 8000
CMD gunicorn --bind=0.0.0.0:8000 - "app.app:create_app()"
The docker-compose file:
# for local development
version: '3'
services:
db:
image: neo4j:latest
environment:
NEO4J_AUTH: neo4j/test
networks:
- neo4j_db
ports:
- '7474:7474'
- '7687:7687'
flask_svc:
build: .
depends_on:
- 'db'
entrypoint:
- flask
- run
- --host=0.0.0.0
environment:
FLASK_DEBUG: 1
FLASK_APP: app.app.py
ports:
- '5000:5000'
volumes:
- '.:/app'
networks:
- neo4j_db
networks:
neo4j_db:
driver: bridge
And I run it with:
docker-compose up --build -d

Answer 1

Try using neomodel==3.2.9
I had a similar issue and rolled back version to get it to work.
Here's the commit that broke things
Looks like they introduced _NODE_CLASS_REGISTRY under neomodel.Database, object which is meant to be a singleton. But with Flask it's not necessarily a singleton because it keeps instantiating new instances of Database with empty _NODE_CLASS_REGISTRY.
I am not sure how to get this to work with 3.3.0