lambda_functions.py

#!/usr/bin/python

import db
import logging
import server
import json
import base64
import os

class LambdaCommon:

	def __init__(self):
		self.log = logging.getLogger("Lambda")

		self.db = self.createDb()
		self.server = server.Server(self.db)
		self.server.init()
		self.resp = None
		self.ctx = None

	def getPageBucket(self):
		pageBucket = "pagebucket"
		if "PAGE_BUCKET" in os.environ:
			pageBucket = os.environ["PAGE_BUCKET"]
		return pageBucket

	def createDb(self):
		pageBucket = self.getPageBucket()

		return db.DBS3(pageBucket)

	def getResponse(self):
		return self.resp

def get_body(event):
	if not "body" in event:
		return None

	if event["body"]==None:
		return None

	if "isBase64Encoded" in event and event["isBase64Encoded"]==True:
		return base64.b64decode(event["body"])

	return event["body"]

def matches(event,meth,path):
	log = logging.getLogger("Lambda")
	if event==None:
		return False

	if not "httpMethod" in event or meth != event["httpMethod"]:
		return False

	if "requestContext" in event and "resourcePath" in event["requestContext"]:
		if path == event["requestContext"]["resourcePath"]:
			log.info("Matched "+meth+" to "+path)
			return True

	return False

def addCorsHeaders(resp):
	headers={}
	headers["Access-Control-Allow-Headers"] = "Content-Type,X-Amz-Date,Authorization,X-Api-Key,X-Amz-Security-Token"
	headers["Access-Control-Allow-Methods"] = "GET,POST,PUT,DELETE,OPTIONS"
	headers["Access-Control-Allow-Origin"] = "*"
	if not "headers" in resp:
		resp["headers"] = {}

	for key in list(headers.keys()):
		if not key in resp["headers"]:
			resp["headers"][key]=headers[key]
	return resp


def single_func(event, context):
	print((json.dumps(event,indent=2)))

	if event==None or not "body" in event or not "httpMethod" in event:
		return upload_webpage(event,context)

	if matches(event,"GET","/v1/pages/{page}"):
		return get_page(event, context)
	if matches(event,"POST","/v1/pages/{page}"):
		return update_page(event, context)
	if matches(event,"PUT","/v1/pages/{page}"):
		return update_page(event, context)
	if matches(event, "GET", "/v1/search/{query}"):
		return search(event, context)
	if "httpMethod" in event and "OPTIONS"==event["httpMethod"]:
		return get_options(event, context)
	
	return {"statusCode":404}

def upload_webpage(event,context):
	obj = LambdaCommon()
	obj.server.copyWebsiteToWebpageBucket(os.environ["WEBSITE_BUCKET"],os.environ["REST_API"],os.environ["REST_STAGE"])


def get_options(event, context):
	return addCorsHeaders({"statusCode":200})


def get_page(event, context):
	obj = LambdaCommon()
	if obj.getResponse() != None:
		return obj.getResponse()

	try:
		page = event["pathParameters"]["page"]

		resp = obj.server.getPage(obj.ctx,page)

		return addCorsHeaders({"statusCode":200,"body":json.dumps(resp,indent=2)})
	except server.AccessDeniedException as e:
		obj.log.exception("Access Denied")
		return addCorsHeaders({"statusCode":403})
	except:
		obj.log.exception("Error")
		return addCorsHeaders({"statusCode":500})
	return addCorsHeaders({"statusCode":404})

def update_page(event, context):
	obj = LambdaCommon()
	if obj.getResponse() != None:
		return obj.getResponse()

	try:
		page = event["pathParameters"]["page"]
		body = json.loads(get_body(event))

		resp = obj.server.updatePage(obj.ctx,page,body)

		return addCorsHeaders({"statusCode":200,"body":json.dumps(resp,indent=2)})
	except server.AccessDeniedException as e:
		obj.log.exception("Access Denied")
		return addCorsHeaders({"statusCode":403})
	except:
		obj.log.exception("Error")
		return addCorsHeaders({"statusCode":500})
	return addCorsHeaders({"statusCode":404})

def search(event, context):
	obj =  LambdaCommon()
	if obj.getResponse() != None:
		return obj.getResponse

	try:
		query = event["pathParameters"]["query"]
		resp = obj.server.search(obj.ctx, query)
		return addCorsHeaders({"statusCode":200,"body":json.dumps(resp,indent=2)})
	except server.AccessDeniedException as e:
	       	obj.log.exception("Access Denied")
	       	return addCorsHeaders({"statusCode":403})
	except:
	      	obj.log.exception("Error")
	      	return addCorsHeaders({"statusCode":500})
	return addCorsHeaders({"statusCode":404})

FORMAT = "%(asctime)-15s %(message)s"
logging.basicConfig(format=FORMAT)