Authentication requirements vary based on
whether you can use the default service account to authenticate
or need to use Google APIs to authenticate.
You can authenticate
in two ways:
Every Google Compute
Engine instance created with the Google Cloud Console or the gcloud
command line tool has a default service account with the name in
email address format:
<project-number>-compute@developer.gserviceaccount.com
The
default service account can manage authentication for monitoring
VMs in the same project as a VM-Series firewall.
If you want to set up
monitoring from a physical firewall or from a VM-Series firewall in
a different project, you must use the Google APIs to authenticate.
There are two prerequisites: