Identify a directory to which these logs are published?

Explanations:

The directory/var/opt/log/ec2is not a standard log directory for cloud-init or cfn logs. It is primarily used for optional software packages and applications.

The file/var/log/lastlogis not related to cloud-init or cfn logs; it stores information about the last login of users. It does not contain startup or initialization logs.

The directory/var/log/is the standard location for various system logs in Linux, including cloud-init logs (/var/log/cloud-init.logand/var/log/cloud-init-output.log) and cfn logs generated during CloudFormation stack operations.

The directory/var/log/ec2is not a standard directory for cloud-init or cfn logs. Standard log files for these processes are located in the/var/log/directory.