Система Ubuntu Linux 18.04.2
Ядро Linux 4.15.0-58-generic на x86_64
Версия ownCloud 10.2.1 (stable)
owncloud работает через https на порту 45320
etc/fail2ban/jail.conf
[owncloud]
enabled = true
port = https
logpath = /var/log/owncloud-acces.log
ignoreip = 192.168.1.59
action = iptables[name=owncloud, port=45320, protocol=tcp]
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etc/fail2ban/filter.d/ownCloud.conf
[Definition]
failregex = {"reqId":".*","level":2,"time":".*","remoteAddr":".*","user":"--","app":"core","method":".*","message":"Login failed: '.*' \(Remote IP: ''\)"}
ignoreregex =
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arbrspb@nas:~$ sudo fail2ban-client status owncloud
Status for the jail: owncloud
|- Filter
| |- Currently failed: 1
| |- Total failed: 47
| `- File list: /var/log/owncloud-acces.log
`- Actions
|- Currently banned: 1
|- Total banned: 3
`- Banned IP list: 192.168.1.166
arbrspb@nas:~$
Точнее не банит а не добавляет Ip в файервол
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sudo iptables -L -n --line
Chain INPUT (policy ACCEPT)
num target prot opt source destination
Chain FORWARD (policy ACCEPT)
num target prot opt source destination
Chain OUTPUT (policy ACCEPT)
num target prot opt source destination
arbrspb@nas:~$
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Пользовался гуглом для поиска информации и для установки опирался на данную инструкцию
https://habr.com/ru/post/255019/ 
