krypton_camera_upload_demo.py

import boto3
import requests
import time

from datetime import datetime
from dateutil.tz import tzlocal
from picamera import PiCamera

region_name = 'YOUR_AWS_REGION'
s3_bucket_name = 'YOUR_S3_BUCKET'

krypton_url = 'https://krypton.soracom.io:8036/v1/provisioning/aws/cognito/open_id_tokens'
metadata_url = 'http://metadata.soracom.io/v1/subscriber'

credential_refresh_interval = 15 * 60

cognito_client = boto3.client('cognito-identity',region_name=region_name)
credential = ''
s3_client = ''

camera = PiCamera()
camera.resolution = (640,480)
camera.start_preview()
time.sleep(2)


def get_metadata():
  response = requests.get(metadata_url)
  metadata = response.json()
  return metadata


def define_image_file_name():
  metadata = get_metadata()
  image_file_name = metadata['imsi'] + '.jpg'
  return image_file_name


def is_camera_enabled():
  metadata = get_metadata()
  if metadata['tags']['camera'] == '1':
    return True
  else:
    return False
    
def get_identity():
  data = requests.get(krypton_url)
  data = data.json()
  return data

def get_credential(identity):
  credential = cognito_client.get_credentials_for_identity(
    IdentityId=identity['identityId'],
    Logins= {
      'cognito-identity.amazonaws.com':identity['token']
    }
  )
  return credential

def get_s3_client(credential):
  secret_key = credential['Credentials']['SecretKey']
  access_key = credential['Credentials']['AccessKeyId']
  token      = credential['Credentials']['SessionToken']

  session = boto3.session.Session(
    aws_access_key_id=access_key,
    aws_secret_access_key=secret_key,
    aws_session_token=token,
    region_name=region_name
  )

  return session.client('s3')

def capture_image(file_name):
  camera.capture(file_name)


image_file_name = define_image_file_name()
print('Our file name is ' + image_file_name)
identity = get_identity()

while True:

  if is_camera_enabled():
    print('Camera flag is ON!')

    if not credential or credential['Credentials']['Expiration'] < datetime.now(tz=tzlocal()):
      credential = get_credential(identity)
      s3_client = get_s3_client(credential)

    capture_image(image_file_name)
    with open(image_file_name,'rb') as img:
      result = s3_client.put_object(
        Bucket=s3_bucket_name,
        Body=img.read(),
        Key='rpi_camera/'+image_file_name
      )
      print(result)

  else:
    print('Camera flag is OFF! Sleep for 60 seconds..')
    #time.sleep(60)