Usage: stratum database <action> [arguments]   (module type: service)

MariaDB server from Debian: databases, users, permissions, backups and the
main settings. root of this computer logs in to MariaDB without a password
(unix socket); other users have passwords.

Service:
  status                         state, settings, databases, users, backups
  start | stop | restart         MariaDB now
  enable | disable               on and at boot / off and not at boot

Databases:
  dbs                            databases with size, tables and users
  db-create <name> [charset]     new database (utf8mb4, utf8mb3, latin1)
  db-drop <name> --yes           delete (a backup is made first)

Users and permissions:
  users                          users with their databases
  user-create <user> [host]      new user; host: localhost (default), %
                                 (everywhere), 10.0.0.% or a host name;
                                 the password is asked (or read from stdin)
  user-passwd <user> [host]      change the password
  user-drop <user> [host]        remove the user
  grant <user> [host] <db|*> <level>    levels: read (SELECT), write (read +
                                 INSERT, UPDATE, DELETE ...), all (everything
                                 in the database), admin (all databases, GRANT)
  revoke <user> [host] <db|*>    no access
  grants <user> [host]           the permissions of a user

Backups (/var/backups/stratum-database, gzip-compressed SQL):
  backup [db|all]                back up now
  backups                        list
  restore <file> [db]            restore (into another database, if given)
  backup-all                     what the backup timer runs

Other:
  secure                         remove anonymous users, remote root, test database
  processes                      running queries

Settings (setting <key> <value>):
  bind localhost|all|<address>   where MariaDB listens (default localhost)
  access local|any|"<net> ..."   who may connect when it listens on the
                                 network (firewall rules, stratum-firewall)
  max-connections <10-5000>      default 151
  buffer auto|<MB>               InnoDB buffer pool (auto: 25 % of RAM)
  slowlog yes|no                 log queries slower than 2 s
  backup daily|weekly|off        automatic backup at 03:15
  keep <1-365>                   backups kept per database (default 7)

Files:
  /etc/stratum/database.conf, /etc/mysql/mariadb.conf.d/90-stratum.cnf
  /var/backups/stratum-database/, /etc/stratum/firewall.d/database.rules
  stratum-database-backup.timer
