monapi.py

#!/usr/bin/env python
'''
Author: Jaakko Lappalainen, 2014. email: jkk.lapp@gmail.com

This program is free software: you can redistribute it and/or modify 
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distri	buted in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
'''
from flask import Flask
from flask import request
from pymongo import MongoClient
from pymongo.errors import ConnectionFailure
from bson.code import Code
from bson.objectid import ObjectId
import json,sys
from flask import jsonify

monapi = Flask(__name__)

class Conf:
	mongoHost = 'localhost'
	mongoPort = 27017

class Message:
	m = ""
	def __init__(self,c,msg):
		self.m = jsonify({ 'status': c, "message": msg })
	def getString(self):
		return self.m

class Response:
	r = ""
	def __init__(self,c,rsp):
		self.r = jsonify({ 'status': c, "message": rsp })
	def getString(self):
		return self.r


# System status
@monapi.route('/')
def index():
	"""Checks local mongodb status"""
	r = Message("N/A", "Unknown")
	try:
		host = MongoClient(Conf.mongoHost,Conf.mongoPort)
		r = Message("OK","MongoDB is running")
		host.close()
	except ConnectionFailure:
		r = Message("Error","No MongoDB instance found.") 
	finally:
		return r.getString()


# Database level
@monapi.route('/<db>')
def getDbInfo(db):
	""" Returns 'db' info """
	host = MongoClient(Conf.mongoHost,Conf.mongoPort)
	if db not in host.database_names():
		r = Message("Error", "Unknown database.")
	else:
		r = Response("OK", json.dumps(host.db.command("dbstats")))
	host.close()
	return r.getString()

@monapi.route('/_dbs')
def listDbs():
	""" List available databases """
	host = MongoClient(Conf.mongoHost,Conf.mongoPort)
	r = Response("OK", json.dumps(host.database_names()))
	host.close()
	return r.getString()

# Collection level
@monapi.route('/<db>/<coll>')
def getCollInfo(db,coll):
	""" Returns 'db.coll' info """
	host = MongoClient(Conf.mongoHost,Conf.mongoPort)
	r = Response("OK", json.dumps(host[db].command({"collstats" : coll})))
	host.close()
	return r.getString()


@monapi.route('/<db>/_colls')
def listColls(db):
	""" Returns 'db' info """
	host = MongoClient(Conf.mongoHost,Conf.mongoPort)	
	r = Response("OK", json.dumps(host[db].collection_names()))
	host.close()
	return r.getString()

# Data retrieval
@monapi.route('/<db>/<coll>/<int:n>')
def getDocByNumber(db,coll,n):
	host = MongoClient(Conf.mongoHost,Conf.mongoPort)
	try:	
		r = Response("OK", json.dumps(str(host[db][coll].find()[n])))
	except IndexError:
		r = Response("Error", "Index out of range: "+str(n)+" >= "+str(host[db][coll].count()))
	host.close()
	return r.getString()

@monapi.route('/<db>/<coll>/_query', methods=['POST'])
def getDocByQuery(db,coll):
	host = MongoClient(Conf.mongoHost,Conf.mongoPort)
	try:	
		query = json.loads(request.data)
		docs = []
		for doc in host[db][coll].find(query):
			docs.append(str(doc).decode('utf8'))
		r = Response("OK",docs)
		#r = Response("OK", json.loads(str(docs)))
	except IndexError:
		r = Response("Error", "Index out of range: "+str(n)+" >= "+str(host[db][coll].count()))
	host.close()
	return r.getString()

# Data storage
@monapi.route('/<db>/<coll>/_insert', methods=['POST'])
def postDoc(db,coll):
	host = MongoClient(Conf.mongoHost,Conf.mongoPort)
	try:
		doc = json.loads(request.data)
		id = host[db][coll].insert(doc)
		r = Message("OK", "Inserted object with ID: "+str(id))
	except ValueError:
		r = Message("Error", "Data must be a valid JSON.")		
	except:
		r = Message("Error", str(sys.exc_info()[0]))
		raise
	host.close()
	return r.getString()

# Map reduce

@monapi.route('/<db>/<coll>/_mr/<output>', methods=['POST'])
def submitMRJob(db,coll,output):
	host = MongoClient(Conf.mongoHost,Conf.mongoPort)
	c = host[db][coll]
	mapper = json.loads(request.data)['mapper']
	reducer = json.loads(request.data)['reducer']
	c.map_reduce(Code(mapper),Code(reducer),output)
	r = Response("OK", "MR job submitted.")
	return r.getString()


# Application start
if __name__ == '__main__':
    monapi.run(debug = True,host='0.0.0.0')