AWS boto to GCS python snippet (not working; do not use!!!)

aws_gcs_s3.py

#!/usr/bin/env python

import boto3
import boto3.session
from boto3.session import Session
from botocore.credentials import CredentialProvider, RefreshableCredentials
from botocore.session import get_session
from botocore.signers import RequestSigner
import botocore.vendored.requests
from botocore.awsrequest import AWSRequest

import logging
import httplib2
import sys
import datetime
import pytz
import time
from datetime import datetime, timedelta

from google.oauth2 import service_account
import json
import google.auth.transport.requests
import requests



boto3.set_stream_logger(name='botocore')


class GCPRequestSigner(RequestSigner):
    def __init__(self, *args, **kwargs):
        #super().__init__(*args, **kwargs)
        return  


class GCPCredentialProvider(CredentialProvider):
    def __init__(self):
        return

    def load(self):
        return self

    def get_frozen_credentials(self):
        target_scopes = [
            'https://www.googleapis.com/auth/devstorage.read_only']
        cc = service_account.Credentials.from_service_account_file(
            '/path/to/svc.json', scopes=target_scopes)
        request = google.auth.transport.requests.Request()
        cc.refresh(request)

        d_with_tz = datetime.now(pytz.utc) + timedelta(seconds=3600)
        session_credentials = RefreshableCredentials(
            access_key="", secret_key="", token="", expiry_time=d_with_tz, refresh_using=None, method=None)
        return session_credentials

    def _get_session_token(self, config):
        ""

def inject_headers(params, **kwargs):
    params['headers']['Authorization'] = 'Bearer ya29.c.ffoooo-ehXggNXHHFV78'
    params['headers']['CustomHeader'] = 'customHeaderValue'

def check_headers(*args, **kwargs):
    print kwargs['request'].headers


def before_call_handler(*args, **kwargs):
    print("before-call event handler " + str(args))
    print("before-call. event handler: kwargs: " + str(kwargs))


def after_call_handler(*args, **kwargs):
    print("after-call. event handler: args: " + str(args))
    print("after-call. event handler: kwargs: " + str(kwargs))


def request_created_handler(*args, **kwargs):
    print("request-created. event handler: args: " + str(args))
    print("request-created. event handler: kwargs: " + str(kwargs))
    req = kwargs.get('request')
    req.headers['Authorization'] = 'Bearer bbbb'
    print(req)

def before_sign_handler(*args, **kwargs):
    print("before-sign. event handler: args: " + str(args))
    print("before-sign. event handler: kwargs: " + str(kwargs))
    req = kwargs.get('request')
    req.headers['Authorization'] = 'Bearer foo'
    print(req)

# https://botocore.amazonaws.com/v1/documentation/api/latest/reference/awsrequest.html#botocore-awsrequest

hooks = botocore.hooks.HierarchicalEmitter()
hooks.register(event_name="before-call.*", handler=before_call_handler)
hooks.register(event_name="after-call.*", handler=after_call_handler)
hooks.register(event_name="request-created.*", handler=request_created_handler)
hooks.register(event_name="before-sign.*", handler=before_sign_handler)


bc_session = botocore.session.Session(event_hooks=hooks)

cred_provider = bc_session.get_component('credential_provider')
cred_provider.insert_before('env', GCPCredentialProvider())

boto3_session = Session(botocore_session=bc_session)
#request_signer
client = boto3_session.client(
    "s3", region_name="auto", endpoint_url="https://storage.googleapis.com")
client.meta.events.register('before-call', inject_headers)
client.meta.events.register('before-sign', check_headers)

response = client.list_objects(Bucket='mineral-minutia-802-binauth')

print("Objects:")
for blob in response["Contents"]:
    print(blob["Key"])