지훈현서 : [Python] Flask에서 Redis를 사용하여 세션 관리하는 샘플

작성시간 : 2015/09/11 17:55
퍼머링크 : mcchae.egloos.com/11184587
작성자 : 지훈현서아빠
덧글수 : 5

플래스크에서 세션 정보는 브라우저의 쿠키를 이용합니다.

해당 정보를 플래스크의 세션객체에 넣고 이용하는데

별도의 레디스 서버를 이용합니다.

레디스가 특별히 좋은 이유는 자동으로 파기 조건을 줄 수 있기 때문입니다.

혹시나 비정상 종료로 사용자가 브라우저를 종료하고 나갔다고 하더라도

해당 레디스에서는 자동으로 해당 세션정보를 시간이 지나면 파기합니다.

우선 아래의 코드와 같습니다.

from uuid import uuid4
from datetime import datetime, timedelta

from flask.sessions import SessionInterface, SessionMixin
from werkzeug.datastructures import CallbackDict
from flask import Flask, session, url_for, redirect

import redis
import cPickle

#########################################################################################
# This is a session object. It is nothing more than a dict with some extra methods
class RedisSession(CallbackDict, SessionMixin):
	def __init__(self, initial=None, sid=None):
		CallbackDict.__init__(self, initial)
		self.sid = sid
		self.modified = False

#########################################################################################
# Session interface is responsible for handling logic related to sessions
# i.e. storing, saving, etc
class RedisSessionInterface(SessionInterface):
	#====================================================================================
	# Init connection
	def __init__(self, host='localhost', port=6379, db=0, timeout=3600):
		self.store = redis.StrictRedis(host=host, port=port, db=db)
		self.timeout = timeout
	#====================================================================================
	def open_session(self, app, request):
		# Get session id from the cookie
		sid = request.cookies.get(app.session_cookie_name)

		# If id is given (session was created)
		if sid:
			# Try to load a session from Redisdb
			stored_session = None
			ssstr = self.store.get(sid)
			if ssstr:
				stored_session = cPickle.loads(ssstr)
			if stored_session:
				# Check if the session isn't expired
				if stored_session.get('expiration') > datetime.utcnow():
					return RedisSession(initial=stored_session['data'],
										sid=stored_session['sid'])
		
		# If there was no session or it was expired...
		# Generate a random id and create an empty session
		sid = str(uuid4())
		return RedisSession(sid=sid)
	#====================================================================================
	def save_session(self, app, session, response):
		domain = self.get_cookie_domain(app)

		# We're requested to delete the session
		if not session:
			response.delete_cookie(app.session_cookie_name, domain=domain)
			return

		# Refresh the session expiration time
		# First, use get_expiration_time from SessionInterface
		# If it fails, add 1 hour to current time
		if self.get_expiration_time(app, session):
			expiration = self.get_expiration_time(app, session)
		else:
			expiration = datetime.utcnow() + timedelta(hours=1)

		# Update the Redis document, where sid equals to session.sid
		ssd = {
			'sid': session.sid,
			'data': session,
			'expiration': expiration
		}
		ssstr = cPickle.dumps(ssd)
		self.store.setex(session.sid, self.timeout, ssstr)

		# Refresh the cookie
		response.set_cookie(app.session_cookie_name, session.sid,
							expires=self.get_expiration_time(app, session),
							httponly=True, domain=domain)

#########################################################################################
# Create an application
app = Flask(__name__)
app.session_interface = RedisSessionInterface()

#########################################################################################
@app.route("/")
def index():
	session.permanent = False
	if not 'refreshed'in session:
		session['refreshed'] = 0

	text = "You refreshed the page %d times" % ( session['refreshed'] )
	text += '<br/><a href="/kill">Reset</a>'
	text += '<br/>dbname="%s"' % session.get('dbname','NULL')
	session['refreshed'] = session['refreshed'] + 1
	return text

#########################################################################################
@app.route("/dbset/<dbname>")
def dbset(dbname):
	session['dbname']=dbname
	return redirect(url_for('index'))

#########################################################################################
@app.route("/kill")
def kill():
	session.clear()
	return redirect(url_for('index'))

app.debug = True

#########################################################################################
if __name__ == "__main__":
	app.run(host="0.0.0.0", port=8080)