Raspberry Pi Data Sender
Python code which collects Arduino data by bluetooth and sends it to REST API using APIGateway
from bluetooth import * # sudo apt-get install bluetooth
import datetime
import json
import time
import requests # pip install requests
# for amazon auth
import sys
import os
import base64
import hashlib
import hmac
URL = 'https://idFromAPIGateway.execute-api.ap-northeast-2.amazonaws.com/prod'
# Read AWS access key from env. variables or configuration file. Best Practice is NOT
# to embed credentials in code
API_KEY = os.environ.get('AWS_API_KEY')
ACCESS_KEY = os.environ.get('AWS_ACCESS_KEY_ID')
SECRET_KEY = os.environ.get('AWS_SECRET_ACCESS_KEY')
# Key derivation functions. See:
# http://docs.aws.amazon.com/general/latest/gr/signature-v4-examples.html#signature-v4-examples-python
def sign(key, msg):
return hmac.new(key, msg.encode('utf-8'), hashlib.sha256).digest()
def getSignatureKey(key, dateStamp, regionName, serviceName):
kDate = sign(('AWS4' + key).encode('utf-8'), dateStamp)
kRegion = sign(kDate, regionName)
kService = sign(kRegion, serviceName)
kSigning = sign(kService, 'aws4_request')
return kSigning
def awsRequest(requestBody):
# requested values
method = 'POST'
service = 'execute-api'
host = 'apigateway.amazonaws.com'
region = 'ap-northeast-2'
endpoint = 'https://hmwzfc5hga.execute-api.ap-northeast-2.amazonaws.com/prod/dust'
content_type = 'application/json'
# POST requests use a content type header. For DynamoDB,
# the content is JSON.
# content_type = 'application/x-amz-json-1.0'
if ACCESS_KEY is None or SECRET_KEY is None:
print('No access key is available.')
sys.exit()
# Create a date for headers and the credential string
t = datetime.datetime.utcnow()
# Format date as YYYYMMDD'T'HHMMSS'Z'
amz_date = t.strftime('%Y%m%dT%H%M%SZ')
# Date w/o time, used in credential scope
date_stamp = t.strftime('%Y%m%d')
# ************* TASK 1: CREATE A CANONICAL REQUEST *************
# http://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html
# Step 1 is to define the verb (GET, POST, etc.)--already done.
# Step 2: Create canonical URI--the part of the URI from domain to query
# string (use '/' if no path)
canonical_uri = '/'
# Step 3: Create the canonical query string. In this example, request
# parameters are passed in the body of the request and the query string
# is blank.
canonical_querystring = ''
# Step 4: Create the canonical headers. Header names must be trimmed
# and lowercase, and sorted in code point order from low to high.
# Note that there is a trailing \n.
canonical_headers = 'host:' + host + '\n' + 'x-amz-date:' + amz_date + '\n'
# canonical_headers = 'content-type:' + content_type + '\n' + 'host:' + host + '\n' + 'x-amz-date:' + amz_date + '\n'
# Step 5: Create the list of signed headers. This lists the headers
# in the canonical_headers list, delimited with ";" and in alpha order.
# Note: The request can include any headers; canonical_headers and
# signed_headers include those that you want to be included in the
# hash of the request. "Host" and "x-amz-date" are always required.
# For DynamoDB, content-type and x-amz-target are also required.
signed_headers = 'host;x-amz-date;'
# Step 6: Create payload hash. In this example, the payload (body of
# the request) contains the request parameters.
payload_hash = hashlib.sha256(requestBody.encode('utf-8')).hexdigest()
# Step 7: Combine elements to create canonical request
canonical_request = method + '\n' + canonical_uri + '\n' + canonical_querystring + \
'\n' + canonical_headers + '\n' + signed_headers + '\n' + payload_hash
# ************* TASK 2: CREATE THE STRING TO SIGN*************
# Match the algorithm to the hashing algorithm you use, either SHA-1 or
# SHA-256 (recommended)
# strCredential = 'AKIAJWA2SJKXKVPF3P5A/20181026/ap-northeast-2/apigateway/aws4_request'
algorithm = 'AWS4-HMAC-SHA256'
credential_scope = date_stamp + '/' + region + \
'/' + service + '/' + 'aws4_request'
# credential_scope = date_stamp + '/' + region + '/' + service + '/' + 'aws4_request'
string_to_sign = algorithm + '\n' + amz_date + '\n' + credential_scope + \
'\n' + hashlib.sha256(canonical_request.encode('utf-8')).hexdigest()
# ************* TASK 3: CALCULATE THE SIGNATURE *************
# Create the signing key using the function defined above.
signing_key = getSignatureKey(SECRET_KEY, date_stamp, region, service)
# Sign the string_to_sign using the signing_key
signature = hmac.new(signing_key, (string_to_sign).encode(
'utf-8'), hashlib.sha256).hexdigest()
# ************* TASK 4: ADD SIGNING INFORMATION TO THE REQUEST *************
# Put the signature information in a header named Authorization.
authorization_header = algorithm + ' ' + 'Credential=' + ACCESS_KEY + '/' + \
credential_scope + ', ' + 'SignedHeaders=' + \
signed_headers + ', ' + 'Signature=' + signature
# For DynamoDB, the request can include any headers, but MUST include "host", "x-amz-date",
# "x-amz-target", "content-type", and "Authorization". Except for the authorization
# header, the headers must be included in the canonical_headers and signed_headers values, as
# noted earlier. Order here is not significant.
# # Python note: The 'host' header is added automatically by the Python 'requests' library.
headers = {'Content-Type': content_type,
'X-Amz-Date': amz_date,
'X-Api-key': API_KEY,
'Authorization': authorization_header}
# ************* SEND THE REQUEST *************
print('\nBEGIN REQUEST++++++++++++++++++++++++++++++++++++')
print('Request URL = ' + endpoint)
r = requests.post(endpoint, data=requestBody, headers=headers)
print('\nRESPONSE++++++++++++++++++++++++++++++++++++')
print('Response code: %d\n' % r.status_code)
print(r.text)
###### EXECUTION CODES ######
print('----------------------- AWS Data Sender -----------------------')
print('')
print(' Ver. 1.0.')
print(' Made by 100kimch@naver.com')
print('')
print(' Get bluetooth data from Arduino and send to AWS APIGateway.')
print('')
print('---------------------------------------------------------------')
# bd_addr = "00:18:E4:35:48:0F"
bd_addr = {
1: "00:18:E4:35:4A:D7",
2: "00:18:E4:35:48:09",
# 3: "00:18:E4:35:48:0F"
}
connected = []
# port = 1
period = 7.0
sock = {}
# print('[Msg] Connection Seccess\n[Msg] Data will be received in ' +
# str(period)+' Seconds.')
while 1:
for i in bd_addr:
try:
sock = BluetoothSocket(RFCOMM)
sock.connect((bd_addr[i], 1))
connected.append(i)
print('[Msg] Connection Success: (' + str(i) + ')', bd_addr[i])
except BluetoothError as err:
print('[Msg] Connection failed: (' + str(i) + ')' + bd_addr[i], err)
continue
print('[Msg] Connection Success except error-occured devices.')
time.sleep(period/2)
try:
sockRecv = sock.recv(100)
except BluetoothError as err:
print('[Msg] could not received data.')
continue
# print('[Dev] data:', sockRecv)
data = sockRecv.decode('utf-8', 'ignore')
print('[Msg]' + str(data))
try:
check1 = data.index("{")
check2 = data[check1:].index("}") + check1
check = True
except ValueError:
check = False
if check:
data = data[check1+1:check2].split(':')
jsonData = {
'time': str(datetime.datetime.now()),
'id': data[0],
'dust': data[1],
'temp': data[2],
'humid': data[3]
}
print('[Msg] jsonData: ', jsonData)
awsRequest(json.dumps(jsonData))
# uploadRate can be set in Arduino Code.
# period = float(data[4])
# print('[Msg] Sending rate changed to ' + data[4])
# time.sleep(period)
else:
print('[Msg] Failed to get data.')
sock.close()
time.sleep(period/2)
# print('[Msg] Socket Closed.')
#############################
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