1、发现的第一个警告信息
server log [06:55:25.594] [warning][reporting] Generating a random key for xpack.reporting.encryptionKey.
To prevent pending reports from failing on restart, please set xpack.reporting.encryptionKey in kibana.yml
根据提示，在配置文件kibana.yml中添加【xpack.reporting.encryptionKey】属性：
xpack.reporting.encryptionKey: "a_random_string"
官方文档：https://www.elastic.co/guide/en/kibana/current/reporting-settings-kb.html
2、发现的第二个警告信息
server log [06:55:25.686] [warning][security] Generating a random key for xpack.security.encryptionKey.
To prevent sessions from being invalidated on restart, please set xpack.security.encryptionKey in kibana.yml
根据提示，在配置文件kibana.yml中添加【xpack.security.encryptionKey】属性：
xpack.security.encryptionKey: "something_at_least_32_characters"
官方文档：https://www.elastic.co/guide/en/kibana/6.x/using-kibana-with-security.html