notifications-api/app/__init__.py

import os
import secrets
import string
import time
import uuid
from contextlib import contextmanager
from time import monotonic

from celery import Celery, Task, current_task
from flask import current_app, g, has_request_context, jsonify, make_response, request
from flask.ctx import has_app_context
from flask_marshmallow import Marshmallow
from flask_migrate import Migrate
from flask_sqlalchemy import SQLAlchemy as _SQLAlchemy
from sqlalchemy import event
from werkzeug.exceptions import HTTPException as WerkzeugHTTPException
from werkzeug.local import LocalProxy

from app.clients import NotificationProviderClients
from app.clients.cloudwatch.aws_cloudwatch import AwsCloudwatchClient
from app.clients.document_download import DocumentDownloadClient
from app.clients.email.aws_ses import AwsSesClient
from app.clients.email.aws_ses_stub import AwsSesStubClient
from app.clients.sms.aws_sns import AwsSnsClient
from notifications_utils import logging, request_helper
from notifications_utils.clients.encryption.encryption_client import Encryption
from notifications_utils.clients.redis.redis_client import RedisClient
from notifications_utils.clients.zendesk.zendesk_client import ZendeskClient


class NotifyCelery(Celery):
    def init_app(self, app):
        self.task_cls = make_task(app)

        # Configure Celery app with options from the main app config.
        self.config_from_object(app.config["CELERY"])

    def send_task(self, name, args=None, kwargs=None, **other_kwargs):
        other_kwargs["headers"] = other_kwargs.get("headers") or {}

        if has_request_context() and hasattr(request, "request_id"):
            other_kwargs["headers"]["notify_request_id"] = request.request_id

        elif has_app_context() and "request_id" in g:
            other_kwargs["headers"]["notify_request_id"] = g.request_id

        return super().send_task(name, args, kwargs, **other_kwargs)


class SQLAlchemy(_SQLAlchemy):
    """We need to subclass SQLAlchemy in order to override create_engine options"""

    def apply_driver_hacks(self, app, info, options):
        sa_url, options = super().apply_driver_hacks(app, info, options)
        if "connect_args" not in options:
            options["connect_args"] = {}
        options["connect_args"]["options"] = "-c statement_timeout={}".format(
            int(app.config["SQLALCHEMY_STATEMENT_TIMEOUT"]) * 1000
        )
        return (sa_url, options)


db = SQLAlchemy()
migrate = Migrate()
ma = Marshmallow()
notify_celery = NotifyCelery()
aws_ses_client = AwsSesClient()
aws_ses_stub_client = AwsSesStubClient()
aws_sns_client = AwsSnsClient()
aws_cloudwatch_client = AwsCloudwatchClient()
encryption = Encryption()
zendesk_client = ZendeskClient()
redis_store = RedisClient()
document_download_client = DocumentDownloadClient()


notification_provider_clients = NotificationProviderClients()

api_user = LocalProxy(lambda: g.api_user)
authenticated_service = LocalProxy(lambda: g.authenticated_service)


def create_app(application):
    from app.config import configs

    notify_environment = os.environ["NOTIFY_ENVIRONMENT"]

    application.config.from_object(configs[notify_environment])

    application.config["NOTIFY_APP_NAME"] = application.name
    init_app(application)

    request_helper.init_app(application)
    db.init_app(application)
    migrate.init_app(application, db=db)
    ma.init_app(application)
    zendesk_client.init_app(application)
    logging.init_app(application)
    aws_sns_client.init_app(application)

    aws_ses_client.init_app()
    aws_ses_stub_client.init_app(stub_url=application.config["SES_STUB_URL"])
    aws_cloudwatch_client.init_app(application)
    # If a stub url is provided for SES, then use the stub client rather than the real SES boto client
    email_clients = (
        [aws_ses_stub_client]
        if application.config["SES_STUB_URL"]
        else [aws_ses_client]
    )
    notification_provider_clients.init_app(
        sms_clients=[aws_sns_client], email_clients=email_clients
    )

    notify_celery.init_app(application)
    encryption.init_app(application)
    redis_store.init_app(application)
    document_download_client.init_app(application)

    register_blueprint(application)

    # avoid circular imports by importing this file later
    from app.commands import setup_commands

    setup_commands(application)

    # set up sqlalchemy events
    setup_sqlalchemy_events(application)

    return application


def register_blueprint(application):
    from app.authentication.auth import (
        requires_admin_auth,
        requires_auth,
        requires_no_auth,
    )
    from app.billing.rest import billing_blueprint
    from app.complaint.complaint_rest import complaint_blueprint
    from app.docs import docs as docs_blueprint
    from app.email_branding.rest import email_branding_blueprint
    from app.events.rest import events as events_blueprint
    from app.inbound_number.rest import inbound_number_blueprint
    from app.inbound_sms.rest import inbound_sms as inbound_sms_blueprint
    from app.job.rest import job_blueprint
    from app.notifications.notifications_ses_callback import ses_callback_blueprint
    from app.notifications.receive_notifications import receive_notifications_blueprint
    from app.notifications.rest import notifications as notifications_blueprint
    from app.organization.invite_rest import organization_invite_blueprint
    from app.organization.rest import organization_blueprint
    from app.performance_dashboard.rest import performance_dashboard_blueprint
    from app.platform_stats.rest import platform_stats_blueprint
    from app.provider_details.rest import provider_details as provider_details_blueprint
    from app.service.callback_rest import service_callback_blueprint
    from app.service.rest import service_blueprint
    from app.service_invite.rest import service_invite as service_invite_blueprint
    from app.status.healthcheck import status as status_blueprint
    from app.template.rest import template_blueprint
    from app.template_folder.rest import template_folder_blueprint
    from app.template_statistics.rest import (
        template_statistics as template_statistics_blueprint,
    )
    from app.upload.rest import upload_blueprint
    from app.user.rest import user_blueprint
    from app.webauthn.rest import webauthn_blueprint

    service_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(service_blueprint, url_prefix="/service")

    user_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(user_blueprint, url_prefix="/user")

    webauthn_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(webauthn_blueprint)

    template_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(template_blueprint)

    status_blueprint.before_request(requires_no_auth)
    application.register_blueprint(status_blueprint)

    docs_blueprint.before_request(requires_no_auth)
    application.register_blueprint(docs_blueprint)

    # delivery receipts
    ses_callback_blueprint.before_request(requires_no_auth)
    application.register_blueprint(ses_callback_blueprint)

    # inbound sms
    receive_notifications_blueprint.before_request(requires_no_auth)
    application.register_blueprint(receive_notifications_blueprint)

    notifications_blueprint.before_request(requires_auth)
    application.register_blueprint(notifications_blueprint)

    job_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(job_blueprint)

    service_invite_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(service_invite_blueprint)

    organization_invite_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(organization_invite_blueprint)

    inbound_number_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(inbound_number_blueprint)

    inbound_sms_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(inbound_sms_blueprint)

    template_statistics_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(template_statistics_blueprint)

    events_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(events_blueprint)

    provider_details_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(
        provider_details_blueprint, url_prefix="/provider-details"
    )

    email_branding_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(
        email_branding_blueprint, url_prefix="/email-branding"
    )

    billing_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(billing_blueprint)

    service_callback_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(service_callback_blueprint)

    organization_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(organization_blueprint, url_prefix="/organizations")

    complaint_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(complaint_blueprint)

    performance_dashboard_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(performance_dashboard_blueprint)

    platform_stats_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(
        platform_stats_blueprint, url_prefix="/platform-stats"
    )

    template_folder_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(template_folder_blueprint)

    upload_blueprint.before_request(requires_admin_auth)
    application.register_blueprint(upload_blueprint)


def init_app(app):

    @app.before_request
    def record_request_details():
        g.start = monotonic()
        g.endpoint = request.endpoint

    @app.after_request
    def after_request(response):
        response.headers.add("X-Content-Type-Options", "nosniff")
        return response

    @app.errorhandler(Exception)
    def exception(error):
        app.logger.exception(error)
        # error.code is set for our exception types.
        msg = getattr(error, "message", str(error))
        code = getattr(error, "code", 500)
        response = make_response(
            jsonify(result="error", message=msg), code, error.get_headers()
        )
        response.content_type = "application/json"
        return response

    @app.errorhandler(WerkzeugHTTPException)
    def werkzeug_exception(e):
        response = make_response(
            jsonify(result="error", message=e.description), e.code, e.get_headers()
        )
        response.content_type = "application/json"
        return response

    @app.errorhandler(404)
    def page_not_found(e):
        msg = e.description or "Not found"
        response = make_response(
            jsonify(result="error", message=msg), 404, e.get_headers()
        )
        response.content_type = "application/json"
        return response


def create_uuid():
    return str(uuid.uuid4())


def create_random_identifier():
    return "".join(
        secrets.choice(string.ascii_uppercase + string.digits) for _ in range(16)
    )


# TODO maintainability what is the purpose of this?  Debugging?
def setup_sqlalchemy_events(app):
    # need this or db.engine isn't accessible
    with app.app_context():

        @event.listens_for(db.engine, "connect")
        def connect(dbapi_connection, connection_record):  # noqa
            pass

        @event.listens_for(db.engine, "close")
        def close(dbapi_connection, connection_record):  # noqa
            pass

        @event.listens_for(db.engine, "checkout")
        def checkout(dbapi_connection, connection_record, connection_proxy):  # noqa
            try:
                # this will overwrite any previous checkout_at timestamp
                connection_record.info["checkout_at"] = time.monotonic()

                # checkin runs after the request is already torn down, therefore we add the request_data onto the
                # connection_record as otherwise it won't have that information when checkin actually runs.
                # Note: this is not a problem for checkouts as the checkout always happens within a web request or task

                # web requests
                if has_request_context():
                    connection_record.info["request_data"] = {
                        "method": request.method,
                        "host": request.host,
                        "url_rule": (
                            request.url_rule.rule if request.url_rule else "No endpoint"
                        ),
                    }
                # celery apps
                elif current_task:
                    connection_record.info["request_data"] = {
                        "method": "celery",
                        "host": current_app.config["NOTIFY_APP_NAME"],  # worker name
                        "url_rule": current_task.name,  # task name
                    }
                # anything else. migrations possibly, or flask cli commands.
                else:
                    current_app.logger.warning(
                        "Checked out sqlalchemy connection from outside of request/task"
                    )
                    connection_record.info["request_data"] = {
                        "method": "unknown",
                        "host": "unknown",
                        "url_rule": "unknown",
                    }
            except Exception:
                current_app.logger.exception("Exception caught for checkout event.")

        @event.listens_for(db.engine, "checkin")
        def checkin(dbapi_connection, connection_record):  # noqa
            pass


def make_task(app):
    class NotifyTask(Task):
        abstract = True
        start = None

        @property
        def queue_name(self):
            delivery_info = self.request.delivery_info or {}
            return delivery_info.get("routing_key", "none")

        @property
        def request_id(self):
            # Note that each header is a direct attribute of the
            # task context (aka "request").
            return self.request.get("notify_request_id")

        @contextmanager
        def app_context(self):
            with app.app_context():
                # Add 'request_id' to 'g' so that it gets logged.
                g.request_id = self.request_id
                yield

        def on_success(self, retval, task_id, args, kwargs):  # noqa
            # enables request id tracing for these logs
            with self.app_context():
                elapsed_time = time.monotonic() - self.start

                app.logger.info(
                    "Celery task {task_name} (queue: {queue_name}) took {time}".format(
                        task_name=self.name,
                        queue_name=self.queue_name,
                        time="{0:.4f}".format(elapsed_time),
                    )
                )

        def on_failure(self, exc, task_id, args, kwargs, einfo):  # noqa
            # enables request id tracing for these logs
            with self.app_context():
                app.logger.exception(
                    "Celery task {task_name} (queue: {queue_name}) failed".format(
                        task_name=self.name,
                        queue_name=self.queue_name,
                    )
                )

        def __call__(self, *args, **kwargs):
            # ensure task has flask context to access config, logger, etc
            with self.app_context():
                self.start = time.monotonic()
                return super().__call__(*args, **kwargs)

    return NotifyTask