Harbor同步镜像报错error_when_collect_tags_forrepos

Harbor同步镜像报错: FetchArtifacts error when collect tags for repos

gayhub issue在2020年5月22日提到了是由于postgresql数据库连接数太少导致的，issue链接：https://github.com/goharbor/harbor/issues/12003

也给了解决方法：

修改 postgresql 配置文件: sed 's/max_connections =.*/max_connections=999/g' /data/database/postgresql.conf
重启 harbor-db 生效: docker restart harbor-db

Postgresql: 如果max_connections设置的太大，就需要操作系统内核kernel.sem配置的越大，不然postgresql会报错, 官网解释: https://www.postgresql.org/docs/9.6/kernel-resources.html

相关错误日志:

Mar 16 10:46:52 192.168.48.1 postgresql[5140]: FATAL:  could not create semaphores: No space left on device
Mar 16 10:46:52 192.168.48.1 postgresql[5140]: DETAIL:  Failed system call was semget(5432129, 17, 03600).
Mar 16 10:46:52 192.168.48.1 postgresql[5140]: HINT:  This error does *not* mean that you have run out of disk space.  It occurs when either the system limit for the maximum number of semaphore sets (SEMMNI), or the system wide maximum number of semaphores (SEMMNS), would be exceeded.  You need to raise the respective kernel parameter.  Alternatively, reduce PostgreSQL's consumption of semaphores by reducing its max_connections parameter.
Mar 16 10:46:52 192.168.48.1 postgresql[5140]: #011The PostgreSQL documentation contains more information about configuring your system for PostgreSQL.
Mar 16 10:46:52 192.168.48.1 postgresql[5140]: LOG:  database system is shut down

解决方法是: