When configuring Cloud Logging to log each IP address accessing an API, what is the first step?

To log each IP address accessing an API, the first step in configuring Cloud Logging is to enable logging on the firewall rule. This action allows incoming network traffic to be recorded, which includes information such as the IP addresses of clients accessing your API.

Enabling logging on the firewall rule ensures that you capture relevant data that can be analyzed later for security auditing and operational insights. This foundational step is crucial as it provides the necessary visibility into the traffic coming through your Google Cloud environment, specifically for APIs that may be protected by firewalls.

The other choices, while relevant to logging and monitoring in various contexts, do not serve as the initial step for specifically capturing API access logs. For example, enabling Packet Mirroring on the VPC deals with copying and analyzing packet data rather than direct logging of access. Installing the Ops Agent is relevant for collecting metrics and logs from the VM instances but does not directly address logging incoming API traffic. Enabling VPC Flow Logs on the subnet would also relate to traffic logging but is secondary to logging enforced through firewall rules, as it focuses on general traffic rather than specific API access logs.