谷歌云API:禁止使用服务帐户密钥访问已启用的API

我在使用服务帐户P12密钥和获取 Http错误403 .

但是,如果我使用Web OAuth(使用客户端ID和机密),则不会出现此问题。但是,我正在创建服务对服务应用程序。

谷歌云API JSON 已启用。

import os
from httplib2 import Http
from pprintpp import pprint

from oauth2client.client import SignedJwtAssertionCredentials
from apiclient.discovery import build
from googleapiclient.errors import HttpError

SITE_ROOT = \
    os.path.dirname(os.path.realpath(__file__))
P12_FILE = \
    "REDACTED-0123456789.p12"

P12_PATH = os.path.join(SITE_ROOT, P12_FILE)
pprint(P12_PATH)

SCOPE = \
    'https://www.googleapis.com/auth/devstorage.read_only'
PROJECT_NAME = \
    'mobileapptracking-insights'
BUCKET_NAME = \
    'pubsite_prod_rev_0123456789'
CLIENT_EMAIL = \
    'REDACTED-service@foo-bar-0123456789.iam.gserviceaccount.com'

private_key = None
with open(P12_PATH, "rb") as p12_fp:
  private_key = p12_fp.read()

credentials = SignedJwtAssertionCredentials(
    CLIENT_EMAIL,
    private_key,
    SCOPE)

http_auth = credentials.authorize(Http())

storage = build('storage', version='v1', http=http_auth)

request = storage.objects().list(bucket=BUCKET_NAME)

try:
    response = request.execute()
except HttpError as error:
    print("HttpError: %s" % str(error))
    raise
except Exception as error:
    print("%s: %s" % (error.__class__.__name__, str(error)))
    raise

print(response)

错误消息:

HttpError: <HttpError 403 when requesting https://www.googleapis.com/storage/v1/b/pubsite_prod_rev_0123456789/o?alt=json returned "Forbidden">

我需要做什么来解决这个问题?