An excessive number of errors is likely abuse of some kind.
This may include application login errors, if the app responds with an appropriate HTTP status code.
Large set of fixes and enhancements for `systemd` and `auto` backends:
* fixes `systemd` bug with missing journal descriptor after rotation by reopening of journal if it is recognized as not alive (gh-3929)
* improve threaded clean-up of all filters, new thread functions `afterStop` (to force clean-up after stop) and `done`, invoking `afterStop` once
* ensure journal-reader is always closed (additional prevention against leaks and "too many open files"), thereby avoid sporadic segfault in systemd module (see https://github.com/systemd/python-systemd/issues/143)
* fixes `systemd` causing "too many open files" error for a lot of journal files and large amout of systemd jails (see new parameter `rotated` below, gh-3391);
* backend `systemd` extended with new parameter `rotated` (default `false`, as prevention against "too many open files"),
that allows to monitor only actual journals and ignore now a lot of rotated files by default; so can drastically reduce
amount of used file descriptors, normally to 1 or 2 descriptors per jail (gh-3391)
* implements automatic switch `backend = auto` to backend `systemd`, when the following is true (RFE gh-3768):
- no files matching `logpath` found for this jail;
- no `systemd_if_nologs = false` is specified for the jail (`true` by default);
- option `journalmatch` is set for the jail or its filter (otherwise it'd be too heavy to allow all auto-jails,
even if they have never been foreseen for journal monitoring);
(option `skip_if_nologs` will be ignored if we could switch backend to `systemd`)
- no files matching `logpath` found for this jail;
- no `systemd_if_nologs = false` (`true` by default) is specified for the jail;
- option `journalmatch` is set for the jail or its filter (otherwise it'd be too heavy to allow all auto-jails, even if they have never been foreseen for journal);
- option `skip_if_nologs` will be ignored if we could switch backend to `systemd`;
closes gh-3768
since line 7 matches successfully now (it was disabled in gh-358 because of obsolete format), it is marked as match:true (line can be removed later if unneeded)
configuration `ignoreip` and fail2ban-client commands `addignoreip`/`delignoreip` extended with `file:...` syntax to ignore IPs from file-ip-set (containing IP, subnet, dns/fqdn or raw strings);
the file would be read lazy on demand, by first ban (and automatically reloaded by update after small latency to avoid expensive stats check on every compare);
the entries inside the file can be separated by comma, space or new line with optional comments (text following chars # or ; after space or newline would be ignored up to next newline)
fix syntax in example, because `dst` as command parameter doesn't have precedence over or-expression, so second `sport` would ignore `dst` and kill any connection for https regardless the IP
David Cook