model-service/model_service/app.py

#!/usr/bin/env python3
import sentry_sdk
from sentry_sdk.integrations.flask import FlaskIntegration
from flask import Flask
from werkzeug.middleware.proxy_fix import ProxyFix
from healthcheck import HealthCheck

# import stuff
from model import db

from utils import register_all_error_handlers, storage, health_database_status

# import views
from views import SVMView, CNNView, RootView

from config import Config

# Tracing stuffs
import jaeger_client
import opentracing
from flask_opentracing import FlaskTracing

if Config.SENTRY_DSN:
    sentry_sdk.init(
        dsn=Config.SENTRY_DSN,
        integrations=[FlaskIntegration()],
        _experiments={"auto_enabling_integrations": True},
        traces_sample_rate=0,
        send_default_pii=True,
        release=Config.RELEASE_ID,
        environment=Config.RELEASEMODE
    )

# create flask app
app = Flask(__name__)
app.wsgi_app = ProxyFix(app.wsgi_app, x_proto=1)

# load config
app.config.from_object(Config)

# initialize stuff
db.init_app(app)
storage.init_app(app)
health = HealthCheck()


@app.before_first_request
def create_db():
    db.create_all()


# register error handlers
register_all_error_handlers(app)


# Setup tracing
def initialize_tracer():
    app.logger.info("Initializing jaeger...")
    jaeger_cfg = jaeger_client.Config(config={}, service_name='model-service', validate=True)
    tracer = jaeger_cfg.initialize_tracer()
    return tracer


tracing = FlaskTracing(initialize_tracer, True, app)

# register views
for view in [SVMView, CNNView, RootView]:
    view.register(app, trailing_slash=False, route_prefix='/model')

health.add_check(health_database_status)
app.add_url_rule("/healthz", "healthcheck", view_func=lambda: health.run())

# start debuggig if needed
if __name__ == "__main__":
    app.run(debug=True)
else:
    import os

    if "gunicorn" in os.environ.get("SERVER_SOFTWARE", ""):
        import logging

        gunicorn_logger = logging.getLogger('gunicorn.error')
        app.logger.handlers = gunicorn_logger.handlers
        app.logger.setLevel(gunicorn_logger.level)

        jaeger_logger = logging.getLogger('jaeger_tracing')
        jaeger_logger.handlers = gunicorn_logger.handlers
        jaeger_logger.setLevel(gunicorn_logger.level)

        app.logger.info("Gunicorn environment detected!")
    else:
        app.logger.info("Not gunicorn")