Usage: fluent-ca-generate DIR_PATH PRIVATE_KEY_PASSPHRASE [--country COUNTRY] [--state STATE] [--locality LOCALITY] [--common-name COMMON_NAME]
        --key-length [KEY_LENGTH]    configure key length. (default: 2048)
        --country [COUNTRY]          configure country. (default: US)
        --state [STATE]              configure state. (default: CA)
        --locality [LOCALITY]        configure locality. (default: Mountain View)
        --common-name [COMMON_NAME]  configure common name (default: Fluentd Forward CA)