Python code snippet to fetch the compute instance details by connecting to Google API Client using Python client library for Google's discovery.

gcpComputeInstanceDetails.py

#vars
  # SERVICE_ACCOUNT_FILE --> Service Account Json file
  # project --> Gcp Project Name
  # zone --> zone in which instance is created
  # instance_name --> Instance name
  
from google.oauth2 import service_account
from googleapiclient import discovery

SCOPES = ["https://www.googleapis.com/auth/cloud-platform"]
SERVICE_ACCOUNT_FILE = "account.json" ##Service Account Json file
credentials = service_account.Credentials.from_service_account_file(SERVICE_ACCOUNT_FILE, scopes=SCOPES)
service = discovery.build('compute', 'v1',credentials=credentials)
service = get_compute_service()
request = service.instances().get(project=project,zone=zone,instance=instance_name)
instance_response = request.execute()
print instance_response['networkInterfaces'][0]['networkIP'] # print the instnace