# Fail2ban missing files after migration/upgrade

**URL:** https://forum.yunohost.org/t/fail2ban-missing-files-after-migration-upgrade/37129
**Category:** Support
**Tags:** fail2ban, service, english
**Created:** [June 1, 2025, 10:32pm UTC](https://forum.yunohost.org/t/fail2ban-missing-files-after-migration-upgrade/37129 "2025-06-01T22:32:13Z")
**Posts on this page:** 7
**Page:** 1

<div class="post-metadata">

### Author: ![Dex](https://forum.yunohost.org/letter_avatar_proxy/v4/letter/d/5e9695/32.png) [@Dex](https://forum.yunohost.org/u/Dex)
#### Post date: [June 1, 2025, 10:32pm UTC](https://forum.yunohost.org/t/fail2ban-missing-files-after-migration-upgrade/37129/1 "2025-06-01T22:32:13Z")

</div>

**What type of hardware are you using** : VPS bought online  
**What YunoHost version are you running** : 12.0.17  
**How are you able to access your server** : The webadmin  
SSH  
**Are you in a special context or did you perform specific tweaking on your YunoHost instance ?** : No

### Describe your issue

I (finally) got around to migrating my installation to 12 and that seemed to go smoothly, all completed and let me log back in - apps all there, data all there. But then when I ran a diagnostic it told me that the fail2ban service wasn’t running.

So I ran `yunohost service status fail2ban` and the output was:

```auto
configuration: broken
configuration-details: 
  - 2025-06-01 17:54:44,740 fail2ban.configreader [3981]: WARNING 'allowipv6' not defined in 'Definition'. Using default one: 'auto'
  - 2025-06-01 17:54:44,741 fail2ban.configreader [3981]: ERROR Found no accessible config files for 'filter.d/sshd' under /etc/fail2ban
  - 2025-06-01 17:54:44,741 fail2ban.jailreader [3981]: ERROR Unable to read the filter 'sshd'
  - 2025-06-01 17:54:44,741 fail2ban.jailsreader [3981]: ERROR Errors in jail 'sshd'.
  - 2025-06-01 17:54:44,741 fail2ban.configreader [3981]: ERROR Found no accessible config files for 'filter.d/nginx-http-auth' under /etc/fail2ban
  - 2025-06-01 17:54:44,741 fail2ban.jailreader [3981]: ERROR Unable to read the filter 'nginx-http-auth'
  - 2025-06-01 17:54:44,741 fail2ban.jailsreader [3981]: ERROR Errors in jail 'nginx-http-auth'.
  - 2025-06-01 17:54:44,743 fail2ban.configreader [3981]: ERROR Found no accessible config files for 'filter.d/postfix' under /etc/fail2ban
  - 2025-06-01 17:54:44,743 fail2ban.jailreader [3981]: ERROR Unable to read the filter 'postfix'
  - 2025-06-01 17:54:44,743 fail2ban.jailsreader [3981]: ERROR Errors in jail 'postfix'.
  - 2025-06-01 17:54:44,743 fail2ban.configreader [3981]: ERROR Found no accessible config files for 'filter.d/dovecot' under /etc/fail2ban
  - 2025-06-01 17:54:44,743 fail2ban.jailreader [3981]: ERROR Unable to read the filter 'dovecot'
  - 2025-06-01 17:54:44,743 fail2ban.jailsreader [3981]: ERROR Errors in jail 'dovecot'.
  - 2025-06-01 17:54:44,744 fail2ban.configreader [3981]: ERROR Found no accessible config files for 'filter.d/recidive' under /etc/fail2ban
  - 2025-06-01 17:54:44,744 fail2ban.jailreader [3981]: ERROR Unable to read the filter 'recidive'
  - 2025-06-01 17:54:44,744 fail2ban.jailsreader [3981]: ERROR Errors in jail 'recidive'.
  - 2025-06-01 17:54:44,744 fail2ban.configreader [3981]: ERROR Found no accessible config files for 'filter.d/pam-generic' under /etc/fail2ban
  - 2025-06-01 17:54:44,744 fail2ban.jailreader [3981]: ERROR Unable to read the filter 'pam-generic'
  - 2025-06-01 17:54:44,744 fail2ban.jailsreader [3981]: ERROR Errors in jail 'pam-generic'.
  - 2025-06-01 17:54:44,746 fail2ban [3981]: ERROR Failed during configuration: Bad value substitution: option 'failregex' in section 'Definition' contains an interpolation key '__prefix_line' which is not a valid option name. Raw value: '^%(__prefix_line)swarning: [-._\\w]+\\[<HOST>\\]: SASL (?:LOGIN|PLAIN|(?:CRAM|DIGEST)-MD5) authentication failed(: [A-Za-z0-9+/]*={0,2})?\\s*$'
  - 2025-06-01 17:54:44,746 fail2ban [3981]: ERROR ERROR: test configuration failed
description: Protects against brute-force and other kinds of attacks from the Internet
last_state_change: 2025-06-01 17:48:48
start_on_boot: enabled
status: failed

```

So I had a look and indeed, none of the files were in `/etc/fail2ban/`

After a bit of searching I eventually found conf files in `/usr/lib/python3/dist-packages/fail2ban/tests/config/` so I copied them all over to `/etc/fail2ban/` and then restarted the fail2ban service but still its failing, this time with errors that I think indicate the files are found but configured wrong:

```auto
configuration: broken
configuration-details: 
  - 2025-06-01 18:04:08,187 fail2ban.configreader [4293]: WARNING 'socket' not defined in 'Definition'. Using default one: '/var/run/fail2ban/fail2ban.sock'
  - 2025-06-01 18:04:08,187 fail2ban.configreader [4293]: WARNING 'pidfile' not defined in 'Definition'. Using default one: '/var/run/fail2ban/fail2ban.pid'
  - 2025-06-01 18:04:08,187 fail2ban.configreader [4293]: WARNING 'logtarget' not defined in 'Definition'. Using default one: '/var/log/fail2ban.log'
  - 2025-06-01 18:04:08,187 fail2ban.configreader [4293]: WARNING 'syslogsocket' not defined in 'Definition'. Using default one: 'auto'
  - 2025-06-01 18:04:08,188 fail2ban.configreader [4293]: WARNING 'logtarget' not defined in 'Definition'. Using default one: 'STDERR'
  - 2025-06-01 18:04:08,188 fail2ban.configreader [4293]: WARNING 'syslogsocket' not defined in 'Definition'. Using default one: 'auto'
  - 2025-06-01 18:04:08,189 fail2ban.configreader [4293]: WARNING 'allowipv6' not defined in 'Definition'. Using default one: 'auto'
  - 2025-06-01 18:04:08,189 fail2ban.configreader [4293]: WARNING 'dbfile' not defined in 'Definition'. Using default one: '/var/lib/fail2ban/fail2ban.sqlite3'
  - 2025-06-01 18:04:08,189 fail2ban.configreader [4293]: WARNING 'dbpurgeage' not defined in 'Definition'. Using default one: '1d'
  - 2025-06-01 18:04:08,189 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'emptyaction'. Using default one: 'auto'
  - 2025-06-01 18:04:08,189 fail2ban.jailreader [4293]: WARNING No filter set for jail emptyaction
  - 2025-06-01 18:04:08,189 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'emptyaction'. Using default one: 'auto'
  - 2025-06-01 18:04:08,189 fail2ban.jailreader [4293]: WARNING No actions were defined for emptyaction
  - 2025-06-01 18:04:08,189 fail2ban.configreader [4293]: WARNING 'enabled' not defined in 'special'. Using default one: False
  - 2025-06-01 18:04:08,189 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'special'. Using default one: 'auto'
  - 2025-06-01 18:04:08,189 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'test-known-interp'. Using default one: 'auto'
  - 2025-06-01 18:04:08,190 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'test-known-interp'. Using default one: 'auto'
  - 2025-06-01 18:04:08,190 fail2ban.configreader [4293]: WARNING 'action' not defined in 'test-known-interp'. Using default one: ''
  - 2025-06-01 18:04:08,190 fail2ban.jailreader [4293]: WARNING No actions were defined for test-known-interp
  - 2025-06-01 18:04:08,190 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'missinglogfiles'. Using default one: 'auto'
  - 2025-06-01 18:04:08,191 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'missinglogfiles'. Using default one: 'auto'
  - 2025-06-01 18:04:08,191 fail2ban.configreader [4293]: WARNING 'action' not defined in 'missinglogfiles'. Using default one: ''
  - 2025-06-01 18:04:08,191 fail2ban.jailreader [4293]: WARNING No actions were defined for missinglogfiles
  - 2025-06-01 18:04:08,191 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'brokenactiondef'. Using default one: 'auto'
  - 2025-06-01 18:04:08,191 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'brokenactiondef'. Using default one: 'auto'
  - 2025-06-01 18:04:08,192 fail2ban.jailreader [4293]: ERROR Invalid action definition 'joho[foo': unexpected option syntax
  - 2025-06-01 18:04:08,192 fail2ban.jailsreader [4293]: ERROR Errors in jail 'brokenactiondef'.
  - 2025-06-01 18:04:08,192 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'brokenfilterdef'. Using default one: 'auto'
  - 2025-06-01 18:04:08,192 fail2ban.jailreader [4293]: ERROR Invalid filter definition 'flt[test': unexpected option syntax
  - 2025-06-01 18:04:08,192 fail2ban.jailsreader [4293]: ERROR Errors in jail 'brokenfilterdef'.
  - 2025-06-01 18:04:08,192 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'brokenaction'. Using default one: 'auto'
  - 2025-06-01 18:04:08,192 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'brokenaction'. Using default one: 'auto'
  - 2025-06-01 18:04:08,193 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'missingaction'. Using default one: 'auto'
  - 2025-06-01 18:04:08,193 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'missingaction'. Using default one: 'auto'
  - 2025-06-01 18:04:08,194 fail2ban.configreader [4293]: ERROR Found no accessible config files for 'action.d/noactionfileforthisaction' under /etc/fail2ban
  - 2025-06-01 18:04:08,194 fail2ban.jailreader [4293]: ERROR Unable to read action 'noactionfileforthisaction'
  - 2025-06-01 18:04:08,194 fail2ban.jailsreader [4293]: ERROR Errors in jail 'missingaction'.
  - 2025-06-01 18:04:08,194 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'missingbitsjail'. Using default one: 'auto'
  - 2025-06-01 18:04:08,194 fail2ban.configreader [4293]: ERROR Found no accessible config files for 'filter.d/catchallthebadies' under /etc/fail2ban
  - 2025-06-01 18:04:08,194 fail2ban.jailreader [4293]: ERROR Unable to read the filter 'catchallthebadies'
  - 2025-06-01 18:04:08,194 fail2ban.jailsreader [4293]: ERROR Errors in jail 'missingbitsjail'.
  - 2025-06-01 18:04:08,194 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'parse_to_end_of_jail.conf'. Using default one: 'auto'
  - 2025-06-01 18:04:08,194 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'parse_to_end_of_jail.conf'. Using default one: 'auto'
  - 2025-06-01 18:04:08,194 fail2ban.jailreader [4293]: WARNING No actions were defined for parse_to_end_of_jail.conf
  - 2025-06-01 18:04:08,195 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'tz_correct'. Using default one: 'auto'
  - 2025-06-01 18:04:08,195 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'tz_correct'. Using default one: 'auto'
  - 2025-06-01 18:04:08,195 fail2ban.configreader [4293]: WARNING 'action' not defined in 'tz_correct'. Using default one: ''
  - 2025-06-01 18:04:08,195 fail2ban.jailreader [4293]: WARNING No actions were defined for tz_correct
  - 2025-06-01 18:04:08,195 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'multi-log'. Using default one: 'auto'
  - 2025-06-01 18:04:08,195 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'sshd'. Using default one: 'auto'
  - 2025-06-01 18:04:08,195 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'sshd'. Using default one: 'auto'
  - 2025-06-01 18:04:08,196 fail2ban.configreader [4293]: WARNING 'action' not defined in 'sshd'. Using default one: ''
  - 2025-06-01 18:04:08,196 fail2ban.jailreader [4293]: WARNING No actions were defined for sshd
  - 2025-06-01 18:04:08,196 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'nginx-http-auth'. Using default one: 'auto'
  - 2025-06-01 18:04:08,196 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'nginx-http-auth'. Using default one: 'auto'
  - 2025-06-01 18:04:08,196 fail2ban.configreader [4293]: WARNING 'action' not defined in 'nginx-http-auth'. Using default one: ''
  - 2025-06-01 18:04:08,196 fail2ban.jailreader [4293]: WARNING No actions were defined for nginx-http-auth
  - 2025-06-01 18:04:08,197 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'postfix'. Using default one: 'auto'
  - 2025-06-01 18:04:08,197 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'postfix'. Using default one: 'auto'
  - 2025-06-01 18:04:08,197 fail2ban.configreader [4293]: WARNING 'action' not defined in 'postfix'. Using default one: ''
  - 2025-06-01 18:04:08,197 fail2ban.jailreader [4293]: WARNING No actions were defined for postfix
  - 2025-06-01 18:04:08,197 fail2ban.configreader [4293]: WARNING 'backend' not defined in 'sasl'. Using default one: 'auto'
  - 2025-06-01 18:04:08,198 fail2ban [4293]: ERROR Failed during configuration: Bad value substitution: option 'failregex' in section 'Definition' contains an interpolation key '__prefix_line' which is not a valid option name. Raw value: '^%(__prefix_line)swarning: [-._\\w]+\\[<HOST>\\]: SASL (?:LOGIN|PLAIN|(?:CRAM|DIGEST)-MD5) authentication failed(: [A-Za-z0-9+/]*={0,2})?\\s*$'
  - 2025-06-01 18:04:08,198 fail2ban [4293]: ERROR ERROR: test configuration failed

```

I’m at a bit of a loss as to how to sort this out. Running the system update says there’s nothing wrong but fail2ban is totally broken.

### Share relevant logs or error messages

Can’t run logs as fail2ban cannot be found.

---

<div class="post-metadata">

### Author: ![otm33](https://forum.yunohost.org/user_avatar/forum.yunohost.org/otm33/32/11941_2.png) [@otm33](https://forum.yunohost.org/u/otm33)
#### Post date: [June 2, 2025, 12:51am UTC](https://forum.yunohost.org/t/fail2ban-missing-files-after-migration-upgrade/37129/2 "2025-06-02T00:51:48Z")

</div>

Hello @Dex  
Have you already tried `sudo yunohost tools regen-conf fail2ban` ?

---

<div class="post-metadata">

### Author: ![Dex](https://forum.yunohost.org/letter_avatar_proxy/v4/letter/d/5e9695/32.png) [@Dex](https://forum.yunohost.org/u/Dex)
#### Post date: [June 2, 2025, 1:03am UTC](https://forum.yunohost.org/t/fail2ban-missing-files-after-migration-upgrade/37129/3 "2025-06-02T01:03:00Z")

</div>

> [@otm33](#):
>
> `sudo yunohost tools regen-conf fail2ban`

I did yes, sorry I forgot to mention that. First time before copying the files and it told me fail2ban didn’t exist (I guess because there was nothing in `/etc/fail2ban`) and the second time after I copied the file which resulted in `The configuration file '/etc/fail2ban/jail.conf' has been manually modified and will not be updated`.

---

<div class="post-metadata">

### Author: ![otm33](https://forum.yunohost.org/user_avatar/forum.yunohost.org/otm33/32/11941_2.png) [@otm33](https://forum.yunohost.org/u/otm33)
#### Post date: [June 2, 2025, 8:09am UTC](https://forum.yunohost.org/t/fail2ban-missing-files-after-migration-upgrade/37129/4 "2025-06-02T08:09:59Z")

</div>

If fail2ban is totally broken and if you didn’t have any filter or jail left in `/etc/fail2ban/jail.d` and `/etc/fail2ban/filter.d`, you can try reinstalling fail2ban. You will likely need to manually add files from [fail2ban repo](https://github.com/fail2ban/fail2ban/tree/master/config) and to recreate jails for your apps.  
This [thread](https://forum.yunohost.org/t/fail2ban-status-failed/36468/22) may help.

---

<div class="post-metadata">

### Author: ![Dex](https://forum.yunohost.org/letter_avatar_proxy/v4/letter/d/5e9695/32.png) [@Dex](https://forum.yunohost.org/u/Dex)
#### Post date: [June 2, 2025, 10:12am UTC](https://forum.yunohost.org/t/fail2ban-missing-files-after-migration-upgrade/37129/5 "2025-06-02T10:12:05Z")

</div>

Thank you. So is it true to say that if I totally remove what I have now (rm directories and purge), then reinstall fail2ban and then run regen-conf that should sort the issue?

---

<div class="post-metadata">

### Author: ![otm33](https://forum.yunohost.org/user_avatar/forum.yunohost.org/otm33/32/11941_2.png) [@otm33](https://forum.yunohost.org/u/otm33)
#### Post date: [June 2, 2025, 10:21am UTC](https://forum.yunohost.org/t/fail2ban-missing-files-after-migration-upgrade/37129/6 "2025-06-02T10:21:38Z")

</div>

> [@Dex](#):
>
> reinstall fail2ban and then run regen-conf

Unfortunately, it’s not so easy… see :

> [@otm33](#):
>
> This [thread](https://forum.yunohost.org/t/fail2ban-status-failed/36468/22) may help.

… I would recommand to backup every file related to fail2ban before reinstalling.

---

<div class="post-metadata">

### Author: ![system](https://forum.yunohost.org/uploads/default/original/2X/f/f59fe8e3ee6b100b4f574d30d6e30479c68b89f0.png) [@system](https://forum.yunohost.org/u/system)
#### Post date: [July 2, 2025, 10:22am UTC](https://forum.yunohost.org/t/fail2ban-missing-files-after-migration-upgrade/37129/7 "2025-07-02T10:22:15Z")

</div>

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