docker-mailserver/docs/content/config/security/fail2ban.md
Brennan Kinney a0ee472501
docs(chore): Normalize for consistency (#2206)
"Brief" summary/overview of changes. See the PR discussion or individual commits from the PR for more details.

---

Only applies to the `docs/content/**` content (_and `setup` command_). `target/` and `test/` can be normalized at a later date.

* Normalize to `example.com`

- Domains normalized to `example.com`: `mywebserver.com`, `myserver.tld`, `domain.com`, `domain.tld`, `mydomain.net`, `my-domain.tld`, `my-domain.com`, `example.org`, `whoami.com`.
- Alternative domains normalized to `not-example.com`: `otherdomain.com`, `otherdomain.tld`, `domain2.tld`, `mybackupmx.com`, `whoareyou.org`.
- Email addresses normalized to `admin@example.com` (in `ssl.md`): `foo@bar.com`, `yourcurrentemail@gmail.com`, `email@email.com`, `admin@domain.tld`.
- Email addresses normalized to `external-account@gmail.com`: `bill@gates321boom.com`, `external@gmail.com`, `myemail@gmail.com`, `real-email-address@external-domain.com`.
- **`faq.md`:** A FAQ entry title with `sample.domain.com` changed to `subdomain.example.com`.
- **`mail-fetchmail.md`:** Config examples with FQDNs for `imap`/`pop3` used `example.com` domain for a third-party, changed to `gmail.com` as more familiar third-party/external MTA.

* Normalize config volume path

- Normalizing local config path references to `./docker-data/dms/config/`: `./config/`, `config/`, \``config`\`, `/etc/` (_volume mount src path prefix_).
- Normalize DMS volume paths to `docker-data/dms/mail-{data,state,log}`: `./mail`, `./mail-state` `./data/mail`, `./data/state`, `./data/logs`, `./data/maildata`, `./data/mailstate`, `./data/maillogs`, (_dropped/converted data volumes: `maildata`, `mailstate`_).
- Other docker images also adopt the `docker-data/{service name}/` prefix.

* `ssl.md` - Use `dms/custom-certs` where appropriate.

* Apply normalizations to README and example `docker-compose.yml`

---

Common terms, sometimes interchangeably used or now invalid depending on context: `mail`, `mail container`, `mail server`, `mail-server`, `mailserver`,`docker-mailserver`, `Docker Mailserver`.

Rough transformations applied to most matches (_conditionally, depending on context_):

- 'Docker Mailserver' => '`docker-mailserver`'
- 'mail container' => '`docker-mailserver`' (_optionally retaining ' container'_)
- 'mail server' => 'mail-server' / '`docker-mailserver`'
- 'mail-server' => '`docker-mailserver`'
- 'mailserver' => 'mail-server' / '`docker-mailserver`'

Additionally I checked `docker run` (_plus `exec`, `logs`, etc, sub-commands_) and `docker-compose` commands. Often finding usage of `mail` instead of the expected `mailserver`

Additionally changes `mailserver` hostname in k8s to `mail` to align with other non-k8s examples.

---

* drive-by revisions

Mostly minor revisions or improvements to docs that aren't related to normalization effort.
2021-09-23 11:29:37 +12:00

2.5 KiB

title hide
Security | Fail2Ban
toc

Fail2Ban is installed automatically and bans IP addresses for 3 hours after 3 failed attempts in 10 minutes by default.

Configuration files

If you want to change this, you can easily edit our github example file: config/fail2ban-jail.cf.

You can do the same with the values from fail2ban.conf, e.g dbpurgeage. In that case you need to edit: config/fail2ban-fail2ban.cf.

The configuration files need to be located at the root of the /tmp/docker-mailserver/ volume bind (usually ./docker-data/dms/config/:/tmp/docker-mailserver/).

This following configuration files from /tmp/docker-mailserver/ will be copied during container startup.

  • fail2ban-jail.cf -> /etc/fail2ban/jail.d/user-jail.local
  • fail2ban-fail2ban.cf -> /etc/fail2ban/fail2ban.local

Docker-compose config

Example configuration volume bind:

    volumes:
      - ./docker-data/dms/config/:/tmp/docker-mailserver/

!!! attention docker-mailserver must be launched with the NET_ADMIN capability in order to be able to install the iptable rules that actually ban IP addresses.

Thus either include `--cap-add=NET_ADMIN` in the `docker run` command, or the equivalent in `docker-compose.yml`:

```yaml
cap_add:
  - NET_ADMIN
```

If you don't you will see errors the form of:

iptables -w -X f2b-postfix -- stderr: "getsockopt failed strangely: Operation not permitted\niptables v1.4.21: can't initialize iptabl
es table `filter': Permission denied (you must be root)\nPerhaps iptables or your kernel needs to be upgraded.\niptables v1.4.21: can'
t initialize iptables table `filter': Permission denied (you must be root)\nPerhaps iptables or your kernel needs to be upgraded.\n"
2016-06-01 00:53:51,284 fail2ban.action         [678]: ERROR   iptables -w -D INPUT -p tcp -m multiport --dports smtp,465,submission -
j f2b-postfix

Manage bans

You can also manage and list the banned IPs with the setup.sh script.

List bans

./setup.sh debug fail2ban

Un-ban

Here 192.168.1.15 is our banned IP.

./setup.sh debug fail2ban unban 192.168.1.15