Source code for flask_graphite.hooks

import logging

from flask import current_app
from graphitesend import GraphiteSendException

from .utils import get_request_metric_prefix

logger = logging.getLogger("flask-graphite")


[docs]class MetricHook(object): """Represent a hook for flask requests This hook decorates a function to make it a suitable Flask hook. The function *must* return a 2-tuple which represents a metric name and it's value. :param function: The function used as hook :param type: The type of hook (before_request, after_request or teardown_request) """ def __init__(self, function, type="after_request"): self.function = function self.setup_hook = None self.type = type def __call__(self, response_or_exception=None): """Proxy the call to the decorated function :param response_or_exception: The argument passed by flask (either a Response object or an exception) """ function_args = [] if not self.is_setup_hook: function_args.append(response_or_exception) graphite_args = self.function(*function_args) if graphite_args is None: return response_or_exception metric_name, metric_value = graphite_args metric_name = get_request_metric_prefix() + '.' + metric_name try: current_app.graphite.send(metric_name, metric_value) except (RuntimeError, GraphiteSendException): # pragma: no cover logger.error("Couldn't send metric \"%s\"", graphite_args) return response_or_exception def __repr__(self): return "{}({})".format(self.__class__.__name__, self.name) @property def name(self): return self.function.__name__ __name__ = name @property def is_setup_hook(self): """Property to test if a hook is a setup hook""" return self.type == "before_request"
[docs] def setup(self, function): """Mark a function as a setup hook for this hook A setup hook is a hook required to run before its main hook. It's implemented as a before_request hook. :param function: The function used as setup hook """ self.setup_hook = MetricHook(function, type="before_request") return self.setup_hook
[docs] def register_into(self, obj): """Register the hook as a request hook in `obj` Can only be used on setup hooks. Bind the hook to a client for other types of hooks. :param obj: Either an application or a blueprint :param client: The client to use with this hook for this application """ if self.setup_hook: self.setup_hook.register_into(obj) try: registering_method = getattr(obj, self.type) except AttributeError: logger.error("Invalid type \"%s\". Couldn't register \"%s\" " "hook into %s.", self.type, self.name, obj) raise return registering_method(self)
__all__ = ["MetricHook"]