AttributeError: 'tuple' object has no attribute 'authorize' - GCP Create Service Account with Workload Identity Federation - github

Question

I am trying to create a service account using Python in GCP. This works fine when i've set env var GOOGLE_APPLICATION_CREDENTIALS to a JSON credentials file, and used the following code:
GoogleCredentials.get_application_default()
However the following code fails in CI - Github Actions using Workload Identity Federation:
import google
import googleapiclient.discovery
import os
from util import get_service_name
environment = os.getenv('ENVIRONMENT')
def create_service_account(requested_project_id):
project_id = requested_project_id
credentials = google.auth.default()
service = googleapiclient.discovery.build(
'iam', 'v1', credentials=credentials)
service_account_name = f'svc-{get_service_name()}'
service_accounts = service.projects().serviceAccounts().list(
name='projects/' + project_id).execute()
service_account_exists = False
for account in service_accounts['accounts']:
if (service_account_name in account['name']):
service_account_exists = True
service_account = account
break
if (service_account_exists == False):
service_account = service.projects().serviceAccounts().create(
name='projects/' + project_id,
body={
'accountId': service_account_name,
'serviceAccount': {
'displayName': service_account_name
}
}).execute()
print(f'{"Already Exists" if service_account_exists else "Created"} service account: ' + service_account['email'])
return service_account
Fails with the error:
File "/opt/hostedtoolcache/Python/3.9.0/x64/lib/python3.9/site-packages/googleapiclient/_helpers.py", line 131, in positional_wrapper
return wrapped(*args, **kwargs) File "/opt/hostedtoolcache/Python/3.9.0/x64/lib/python3.9/site-packages/googleapiclient/discovery.py", line 298, in build
service = build_from_document( File "/opt/hostedtoolcache/Python/3.9.0/x64/lib/python3.9/site-packages/googleapiclient/_helpers.py", line 131, in positional_wrapper
return wrapped(*args, **kwargs) File "/opt/hostedtoolcache/Python/3.9.0/x64/lib/python3.9/site-packages/googleapiclient/discovery.py", line 600, in build_from_document
http = _auth.authorized_http(credentials) File "/opt/hostedtoolcache/Python/3.9.0/x64/lib/python3.9/site-packages/googleapiclient/_auth.py", line 119, in authorized_http
return credentials.authorize(build_http()) AttributeError: 'tuple' object has no attribute 'authorize'
I am using the following Github Action to authenticate with Google
- name: Authenticate to Google Cloud To Create Service Account
uses: google-github-actions/auth#v0.4.3
with:
workload_identity_provider: 'projects/xxx/locations/global/workloadIdentityPools/github-actions-identity-pool/providers/github-provider'
service_account: 'svc-iam-creator-dev#acme-dev-tooling.iam.gserviceaccount.com'
Can anyone help?

Answer 1

You have two problems. This line of code is failing:
credentials = google.auth.default()
Problem 1 - Generate an Google OAuth Access Token
Change the GitHub Actions Step to:
- name: Authenticate to Google Cloud To Create Service Account
uses: google-github-actions/auth#v0.4.3
with:
token_format: 'access_token' # Your python code needs an access token
access_token_lifetime: '300s' # make this value small but long enough to complete the job
workload_identity_provider: 'projects/xxx/locations/global/workloadIdentityPools/github-actions-identity-pool/providers/github-provider'
service_account: 'svc-iam-creator-dev#acme-dev-tooling.iam.gserviceaccount.com'
Problem 2 - Creating Credentials
This line will not work because the credentials are not available from ADC (Application Default Credentials).
credentials = google.auth.default()
Pass the access token generated by Workload Identity Federation to your program from from the GitHub Actions output:
${{ steps.auth.outputs.access_token }}
Create the credentials from the access token:
credentials = google.oauth2.credentials.Credentials(access_token)
service = googleapiclient.discovery.build('iam', 'v1', credentials=credentials)