因此，当我测试时一切似乎都正常，但是 fail2ban 无法禁止甚至在访问日志中看不到任何 IP 地址。
这是我的设置：
在 jail.local 我有：
[http-get-dos]
enabled = true
port = http,https
filter = http-get-dos
logpath = /var/log/httpd/access_log
maxretry = 10
findtime = 120
bantime = -1
action = iptables[name=HTTP, port=http, protocol=tcp]
在 http-get-dos.conf 中我有：
[Definition]
failregex = ^<HOST> -.*\"(GET|POST).*
ignoreregex =
运行 fail2ban-regex /var/log/httpd/access_log /etc/fail2ban/filter.d/http-get-dos.conf 我得到：
Running tests
=============
Use failregex filter file : http-get-dos, basedir: /etc/fail2ban
Use log file : /var/log/httpd/access_log
Use encoding : UTF-8
Results
=======
Failregex: 3586 total
|- #) [# of hits] regular expression
| 1) [3586] ^<HOST> -.*\"(GET|POST).*
`-
Ignoreregex: 0 total
Date template hits:
|- [# of hits] date format
| [3601] Day(?P<_sep>[-/])MON(?P=_sep)Year[ :]?24hour:Minute:Second(?:\.Microseconds)?(?: Zone offset)?
`-
Lines: 3601 lines, 0 ignored, 3586 matched, 15 missed
[processed in 0.38 sec]
|- Missed line(s):
| 77.72.83.87 - - [13/Jan/2019:11:01:23 +0000] "\x03" 400 226 "-" "-"
| 122.112.227.18 - - [13/Jan/2019:12:34:51 +0000] "PROPFIND / HTTP/1.1" 405 236 "-" "-"
| 181.22.180.152 - - [14/Jan/2019:17:56:08 +0000] "-" 408 - "-" "-"
| 89.248.172.90 - - [14/Jan/2019:22:40:15 +0000] "-" 408 - "-" "-"
| 89.248.172.90 - - [14/Jan/2019:22:40:35 +0000] "-" 408 - "-" "-"
| 103.105.59.124 - - [15/Jan/2019:00:44:14 +0000] "PROPFIND / HTTP/1.1" 405 236 "-" "-"
| 118.89.138.232 - - [15/Jan/2019:05:12:34 +0000] "PROPFIND / HTTP/1.1" 405 236 "-" "-"
| 66.240.205.34 - - [15/Jan/2019:23:48:20 +0000] "Gh0st\xad" 400 226 "-" "-"
| 129.204.78.36 - - [16/Jan/2019:05:57:50 +0000] "PROPFIND / HTTP/1.1" 405 236 "-" "-"
| 104.128.144.131 - - [16/Jan/2019:19:06:23 +0000] "HEAD /redirect.php HTTP/1.0" 404 - "-" "www.probethenet.com scanner"
| 59.36.132.222 - - [16/Jan/2019:20:42:28 +0000] "CONNECT www.baidu.com:443 HTTP/1.1" 301 229 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.102 Safari/537.36"
| 123.200.24.163 - - [17/Jan/2019:08:46:30 +0000] "PROPFIND / HTTP/1.1" 405 236 "-" "-"
| 79.115.160.167 - - [17/Jan/2019:22:36:03 +0000] "-" 408 - "-" "-"
| ::1 - - [17/Jan/2019:23:08:46 +0000] "OPTIONS * HTTP/1.0" 200 - "-" "Apache/2.4.6 (CentOS) PHP/7.2.13 (internal dummy connection)"
| 79.115.160.167 - - [17/Jan/2019:23:11:51 +0000] "-" 408 - "-" "-"
tail fail2ban.log -f，并且我还重新启动了fail2ban，以便您可以看到发生了什么：
2019-01-18 00:23:40,655 fail2ban.filter [15412]: INFO Set findtime = 120
2019-01-18 00:23:40,667 fail2ban.jail [15412]: INFO Jail 'sshd' started
2019-01-18 00:23:40,668 fail2ban.filtersystemd [15412]: NOTICE Jail started without 'journalmatch' set. Jail regexs will be checked against all journal entries, which is not advised for performance reasons.
2019-01-18 00:23:40,673 fail2ban.jail [15412]: INFO Jail 'http-get-dos' started
2019-01-18 00:23:40,773 fail2ban.actions [15412]: NOTICE [sshd] Ban 124.93.228.42
2019-01-18 00:25:22,970 fail2ban.filter [15412]: INFO [sshd] Found 129.204.34.155
2019-01-18 00:27:35,921 fail2ban.filter [15412]: INFO [sshd] Found 212.237.8.162
2019-01-18 00:27:49,936 fail2ban.filter [15412]: INFO [sshd] Found 142.93.190.223
2019-01-18 00:33:00,711 fail2ban.filter [15412]: INFO [sshd] Found 106.12.203.146
2019-01-18 00:33:23,489 fail2ban.filter [15412]: INFO [sshd] Found 69.194.44.230
2019-01-18 00:35:25,864 fail2ban.server [15412]: INFO Stopping all jails
2019-01-18 00:35:26,700 fail2ban.actions [15412]: NOTICE [sshd] Unban 124.93.228.42
2019-01-18 00:35:26,925 fail2ban.jail [15412]: INFO Jail 'sshd' stopped
2019-01-18 00:35:27,915 fail2ban.jail [15412]: INFO Jail 'http-get-dos' stopped
2019-01-18 00:35:27,919 fail2ban.server [15412]: INFO Exiting Fail2ban
2019-01-18 00:35:28,106 fail2ban.server [15592]: INFO Changed logging target to /var/log/fail2ban.log for Fail2ban v0.9.7
2019-01-18 00:35:28,107 fail2ban.database [15592]: INFO Connected to fail2ban persistent database '/var/lib/fail2ban/fail2ban.sqlite3'
2019-01-18 00:35:28,110 fail2ban.jail [15592]: INFO Creating new jail 'sshd'
2019-01-18 00:35:28,129 fail2ban.jail [15592]: INFO Jail 'sshd' uses systemd {}
2019-01-18 00:35:28,144 fail2ban.jail [15592]: INFO Initiated 'systemd' backend
2019-01-18 00:35:28,145 fail2ban.filter [15592]: INFO Set maxRetry = 5
2019-01-18 00:35:28,146 fail2ban.filter [15592]: INFO Set jail log file encoding to UTF-8
2019-01-18 00:35:28,146 fail2ban.actions [15592]: INFO Set banTime = -1
2019-01-18 00:35:28,146 fail2ban.filter [15592]: INFO Set findtime = 600
2019-01-18 00:35:28,146 fail2ban.filter [15592]: INFO Set maxlines = 10
2019-01-18 00:35:28,203 fail2ban.filtersystemd [15592]: INFO Added journal match for: '_SYSTEMD_UNIT=sshd.service + _COMM=sshd'
2019-01-18 00:35:28,210 fail2ban.jail [15592]: INFO Creating new jail 'http-get-dos'
2019-01-18 00:35:28,210 fail2ban.jail [15592]: INFO Jail 'http-get-dos' uses systemd {}
2019-01-18 00:35:28,211 fail2ban.jail [15592]: INFO Initiated 'systemd' backend
2019-01-18 00:35:28,212 fail2ban.filter [15592]: INFO Set maxRetry = 10
2019-01-18 00:35:28,212 fail2ban.filter [15592]: INFO Set jail log file encoding to UTF-8
2019-01-18 00:35:28,213 fail2ban.actions [15592]: INFO Set banTime = -1
2019-01-18 00:35:28,213 fail2ban.filter [15592]: INFO Set findtime = 120
2019-01-18 00:35:28,222 fail2ban.filter [15592]: INFO [sshd] Found 212.237.8.162
2019-01-18 00:35:28,224 fail2ban.filter [15592]: INFO [sshd] Found 142.93.190.223
2019-01-18 00:35:28,229 fail2ban.filter [15592]: INFO [sshd] Found 106.12.203.146
2019-01-18 00:35:28,232 fail2ban.filter [15592]: INFO [sshd] Found 69.194.44.230
2019-01-18 00:35:28,238 fail2ban.jail [15592]: INFO Jail 'sshd' started
2019-01-18 00:35:28,239 fail2ban.filtersystemd [15592]: NOTICE Jail started without 'journalmatch' set. Jail regexs will be checked against all journal entries, which is not advised for performance reasons.
2019-01-18 00:35:28,242 fail2ban.jail [15592]: INFO Jail 'http-get-dos' started
2019-01-18 00:35:28,355 fail2ban.actions [15592]: NOTICE [sshd] Ban 124.93.228.42
fail2ban-client 状态和 fail2ban-client 状态 http-get-dos
Status
|- Number of jail: 2
`- Jail list: http-get-dos, sshd
|- Filter
| |- Currently failed: 0
| |- Total failed: 0
| `- Journal matches:
`- Actions
|- Currently banned: 0
|- Total banned: 0
`- Banned IP list:
所以从我所看到的情况来看，一切似乎都在正常工作，肯定 sshd 过滤器正在工作，但这个 http-get-dos 过滤器根本不起作用，但当我运行 ail2ban-regex /var/log/httpd/access_log /etc/fail2ban/filter.d/http-get-dos.conf 时没有任何问题
我在 digital ocean 和 Fail2Ban v0.9.7 上使用 CentOS 7，并且我还在 jail.local 中将后端更改为 systemd：backend = systemd
有人知道为什么这不起作用吗？升级到 Fail2ban v0.11.0.dev3 仍然存在同样的问题。
答案1
我还在 jail.local 中将后端更改为 systemd：backend = systemd
嗯，这可能是原因——如果您配置了 systemd 后端，fail2ban 将监控 systemd-journal（而不是日志文件）。
只需尝试针对登录日志文件的服务监狱进行重新配置：
[http-get-dos]
backend = auto
顺便说一句，在 2 分钟内永久禁止 10 个请求对我来说太难了，尤其是它似乎要捕获每个请求（我没有看到像在您的正则表达式中那样涵盖状态代码的部分[45]0\d）。