I try to use the flask cli to start my application, i.e. flask run. I use the FLASK_APP environment variable to point to my application, i.e. export FLASK_APP=package_name.wsgi:app
In my wsgi.py file, I create the app with a factory function, i.e. app = create_app(config) and my create_app method looks like this:
def create_app(config_object=LocalConfig):
app = connexion.App(config_object.API_NAME,
specification_dir=config_object.API_SWAGGER_DIR,
debug=config_object.DEBUG)
app.app.config.from_object(config_object)
app.app.json_encoder = JSONEncoder
app.add_api(config_object.API_SWAGGER_YAML,
strict_validation=config_object.API_SWAGGER_STRICT,
validate_responses=config_object.API_SWAGGER_VALIDATE)
app = register_extensions(app)
app = register_blueprints(app)
return app
However, the application doesn't start, I get the error:
A valid Flask application was not obtained from "package_name.wsgi:app".
Why is this?
I can start my app normally when I use gunicorn, i.e. gunicorn package_name.wsgi:app
My create_app function didn't return an object of class flask.app.Flask but an object of class connexion.apps.flask_app.FlaskApp, because I am using the connexion framework.
In my wsgi.py file, I could simply set:
application = create_app(config)
app = application.app
I didn't even have to do export FLASK_APP=package_name.wsgi:app anymore, autodescovery worked if the flask run command was executed in the folder where the wsgi.py file is.
application = create_app(config)
app = application.app
App = app.app
For me I just created another variable pointing to connexion.app.Flask type and I set the environ as below
export FLASK_APP= __main__:App
flask shell
Related
I'm running into a problem when using Flask with a gremlin database (it's an Amazon Neptune database) and using uWSGI. Everything works fine in my unit tests which use the test_client provided by Flask. However, in production we use uWSGI and there I get the following error:
There is no current event loop in thread 'uWSGIWorker4Core1'.
My app code is creating a connection to the database before a request and assigning it to the Flask g object. During teardown, the database connection is removed. The error happens when the app is trying to close the connection.
from flask import Flask, g
from gremlin_python.structure.graph import Graph
from gremlin_python.driver.driver_remote_connection import DriverRemoteConnection
from gremlin_python.process.anonymous_traversal import traversal
app = Flask(__name__, instance_relative_config=True)
#app.before_request
def _db_connect():
if not hasattr(g, 'graph_conn'):
g.graph_conn = DriverRemoteConnection(app.config['DATABASE_HOST'],'g')
g.gg = traversal().withRemote(g.graph_conn)
# This hook ensures that the connection is closed when we've finished
# processing the request.
#app.teardown_appcontext
def _db_close(exc):
if hasattr(g, 'graph_conn'):
g.graph_conn.close(). # <- ERROR THROWN AT THIS LINE
del g.graph_conn
the uWSGI config does use multiple threads:
[uwsgi]
http = 0.0.0.0:3031
manage-script-name = true
module = dogmaserver:app
processes = 4
threads = 2
offload-threads = 2
stats = 0.0.0.0:9191
But my understanding of how Flask's g object worked would be that it is all on the same thread. Can anyone let me know what I'm missing?
I'm using Flask 1.0.2, gremlinpython 3.4.11 and uWSGI 2.0.17.1.
I used a workaround by removing the threads configuration option in uWSGI which makes there only be a single thread per process.
I am trying to add custom token for user authentication (phone number and password) and as per reference documents I would like to configure server to generate custom token.
I have installed, $ sudo pip install firebase-admin
and also setup an environment : export GOOGLE_APPLICATION_CREDENTIALS="[to json file at my server]"
I am using Django project at my server where i have created all my APIs.
I am stucked at this point where it says to initialize app:
default_app = firebase_admin.initialize_app()
Where should i write the above statement within Django files? and how should i generate endpoint to get custom token?
Regards,
PD
pip install firebase-admin
credentials.json file includes some private keys. So, you can’t add to your project directly. If you’re using the git version system and you want to host this file in your project folder, you must add the file name to your “.gitignore”.
Set your operation system environ variable. You can use for MacOSX or Linux distributions; For set a variable in window os (https://www.computerhope.com/issues/ch000549.htm).
$ export GOOGLE_APPLICATION_CREDENTIALS='/path/to/credentials.json'
This part is important, google package (It came with firebase_admin package) looking at some conditions for credentials. One of them is os.environ.get(‘GOOGLE_APPLICATION_CREDENTIALS’). If you set this file, than you don’t need to anythig fot initialize firebase. Otherwise you should define manually.
For initial firebase look at. Set up configurations (https://firebase.google.com/docs/firestore/quickstart#initialize )
Create a file named “firebase.py”.
$ touch firebase.py
Now we can use the “firebase_admin” package for querying. Our firebase.py seems like;
import time
from datetime import timedelta
from uuid import uuid4
from firebase_admin import firestore, initialize_app
__all__ = ['send_to_firebase', 'update_firebase_snapshot']
initialize_app()
def send_to_firebase(raw_notification):
db = firestore.client()
start = time.time()
db.collection('notifications').document(str(uuid4())).create(raw_notification)
end = time.time()
spend_time = timedelta(seconds=end - start)
return spend_time
def update_firebase_snapshot(snapshot_id):
start = time.time()
db = firestore.client()
db.collection('notifications').document(snapshot_id).update(
{'is_read': True}
)
end = time.time()
spend_time = timedelta(seconds=end - start)
return spend_time
You Refer this link(https://medium.com/#canadiyaman/how-to-use-firebase-with-django-project-34578516bafe)
I'm trying to build a basic flask app for learning purposes. everything flows smoothly, but there's an issue I don't understand. in my run.py file, I have the following line:
app.config.from_object('config.prodConfig')
This loads config.py in the root, which contains the following code:
class Config:
SECRET_KEY = '1234567890'
STATIC_FOLDER = 'static'
TEMPLATES_FOLDER = 'templates'
class devConfig(Config):
FLASK_ENV = 'development'
DEBUG = True
TESTING = True
class prodConfig(Config):
FLASK_ENV = 'production'
DEBUG = False
TESTING = False
my understanding is that Config contains a few "default" settings. devConfig and prodConfig are based on Config, so will always contain those values, but each will have different env, debug and testing value. though I don't get any errors and debug seems to be activated, when I run my instance of Flask it tells me I'm running in production, regardless of what I do.
* Serving Flask app "run" (lazy loading)
* Environment: production
WARNING: This is a development server. Do not use it in a production deployment.
Use a production WSGI server instead.
* Debug mode: on
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
* Restarting with stat
* Debugger is active!
I'm not interested in setting the env variable in the terminal/environment, I know how to do that. what I'm interested in is why this doesn't work. after all, the FLASK_ENV directive is a valid one and it should load when instructed to.
What am I doing wrong?
With Chase's comment in mind, about not setting the FLASK_ENV in the app. Pass a dict of your configurations from your config.py and select the appropriate config based on the FLASK_ENV set outside your app, e.g. with a .env file.
config.py
class BaseConfig:
...
class DevConfig(BaseConfig):
...
class ProdConfig(BaseConfig):
...
configs = {"development": DevConfig, "production": ProdConfig}
app.py
import os
from flask import FLask
from config import configs
...
app.config.from_object(configs[os.environ.get("FLASK_ENV", "development")])
I can't seem to access my env variables' values inside my app. I'm loading my env variables into my app with a .env file and the dotenv package; I learned about it here.
My .env
FLASK_ENV=development
FLASK_APP=app.py
DEBUG=ON
TESTING=False
I want to use the value of the TESTING variable inside my app and run certain code based on whether it is True or False.
How can I get these values? The docs say
Certain configuration values are also forwarded to the Flask object so
you can read and write them from there: app.testing = True
But I get module 'app' has no attribute 'testing'
When I log app by itself I see a Flask object. When I log this out like app.Flask, I see the env variables, but these appear like this, with no refernce to the current value.
{'__name__': 'TESTING', 'get_converter': None}
I want to be able to do something like:
app.testing => False
app.FLASK_ENV => development
and then eventually:
if app.testing == True:
<do something>
PS - I know the app loads this .env file okay because if I remove the values the environment changes back to production, the default.
#settings.py
from pathlib import Path # python3 only
from dotenv import load_dotenv
load_dotenv(verbose=True)
env_path = Path('.') / '.env'
load_dotenv(dotenv_path=env_path)
import os
print(os.environ['TESTING'])
Equivalent in JS is process.env
I have a project which has a directory setup like:
myproject
someapp
sites
foo
settings.py - site specific
settings.py - global
I am using twisted web.wsgi to serve this project. The problem am I running into is setting up the correct environment.
import sys
import os
from twisted.application import internet, service
from twisted.web import server, resource, wsgi, static, vhost
from twisted.python import threadpool
from twisted.internet import reactor
from django.core.handlers.wsgi import WSGIHandler
from django.core.management import setup_environ,ManagementUtility
sys.path.append(os.path.abspath("."))
sys.path.append(os.path.abspath("../"))
DIRNAME= os.path.dirname(__file__)
SITE_OVERLOADS = os.path.join(DIRNAME,'sites')
def import_module(name):
mod = __import__(name)
components = name.split('.')
for comp in components[1:]:
mod = getattr(mod,comp)
return mod
def buildServer():
hosts = [d for d in os.listdir(SITE_OVERLOADS) if not os.path.isfile(d) and d != ".svn"]
root = vhost.NameVirtualHost()
pool = threadpool.ThreadPool()
pool.start()
reactor.addSystemEventTrigger('after', 'shutdown', pool.stop)
for host in hosts:
settings = os.path.join(SITE_OVERLOADS,"%s/settings.py" % host)
if os.path.exists(settings):
sm = "myproject.sites.%s.settings" % host
settings_module = import_module(sm)
domain = settings_module.DOMAIN
setup_environ(settings_module)
utility = ManagementUtility()
command = utility.fetch_command('runserver')
command.validate()
wsgi_resource = wsgi.WSGIResource(reactor,pool,WSGIHandler())
root.addHost(domain,wsgi_resource)
return root
root = buildServer()
site = server.Site(root)
application = service.Application('MyProject')
sc = service.IServiceCollection(application)
i = internet.TCPServer(8001, site)
i.setServiceParent(sc)
I am trying to setup vhosts for each site which has a settings module in the subdirectory "sites". However, it appears that the settings are being shared for each site.
Django projects within the same Python process will share the same settings. You will need to spawn them as separate processes in order for them to use separate settings modules.
Since your goal is a bunch of shared-nothing virtual hosts, you probably won't benefit from trying to set up your processes in anything but the simplest way. So, how about changing your .tac file to just launch a server for a single virtual host, starting up a lot of instances (manually, with a shell script, with another simple Python script, etc), and then putting a reverse proxy (nginx, Apache, even another Twisted Web process) in front of all of those processes?
You could do this all with Twisted, and it might even confer some advantages, but for just getting started you would probably rather focus on your site than on minor tweaks to your deployment process. If it becomes a problem that things aren't more integrated, then that would be the time to revisit the issue and try to improve on your solution.