Commit Graph

19 Commits

Author SHA1 Message Date
9db104efa6
roles/common: Bump version checks to Debian 9 2019-10-26 16:37:27 +02:00
0605f70f2e
roles/common: Add support for fail2ban
This is active banning of IPs that are brute forcing login attempts
to SSH, versus the passive banning of 10,000 abusive IPs from the
abuseipdb.com blacklist. For now I am banning IPs that fail to log
in successfully more than twelve times in a one-hour period, but
these settings might change, and I can override them at the group
and host level if needed.

Currently this works for CentOS 7, Ubuntu 16.04, and Ubuntu 18.04,
with minor differences in the systemd configuration due to older
versions on some distributions.

You can see the status of the jail like this:

    # fail2ban-client status sshd
    Status for the jail: sshd
    |- Filter
    |  |- Currently failed: 0
    |  |- Total failed:     0
    |  `- Journal matches:  _SYSTEMD_UNIT=sshd.service + _COMM=sshd
    `- Actions
       |- Currently banned: 1
       |- Total banned:     1
       `- Banned IP list:   106.13.112.20

You can unban IPs like this:

    # fail2ban-client set sshd unbanip 106.13.112.20
2019-10-26 16:36:07 +02:00
25e0fd3557
roles/common: Use individual calls with firewalld
Seems to work around an issue when firewalld is using the nftables
backend with iptables 1.8.2 on Debian 10. Alternatively I could go
back to using the iptables backend... hmm.

See: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=914694
2019-10-18 22:49:29 +03:00
cac38af09b
roles/common: Use nftables firewalld backend on Debian 10
nftables is the iptables replacement. There is support for nftables
in firewalld since v0.6.0.

See: https://firewalld.org/2018/07/nftables-backend
2019-10-18 19:02:17 +03:00
7c0b458bc1
roles/common: Don't use iptables from buster-backports
This causes problems every time I re-run the Ansible tag because the
nightly apt security uses a different sources.list and the indexes
are then missing buster-backports. I could add a cache update to the
task, but actually I think the original bug I was trying to solve is
finally fixed, and I'm going to switch to nftables anyways.
2019-10-18 18:53:21 +03:00
80df220602
roles/common: Restart firewalld instead of reload
I'm having problems with reload hanging on Debian 10 so I will just
revert to the older behavior of restarting.
2019-10-05 12:29:30 +03:00
c2a92269e4
roles/common: Add ipsets of abusive IPs to firewalld
This uses the ipsets feature of the Linux kernel to create lists of
IPs (though could be MACs, IP:port, etc) that we can block via the
existing firewalld zone we are already using. In my testing it works
on CentOS 7, Ubuntu 16.04, and Ubuntu 18.04.

The list of abusive IPs currently comes from HPC's systemd journal,
where I filtered for hosts that had attempted and failed to log in
over 100 times. The list is formatted with tidy, for example:

    $ tidy -xml -iq -m -w 0 roles/common/files/abusers-ipv4.xml

See: https://firewalld.org/2015/12/ipset-support
2019-10-05 12:28:30 +03:00
532b533516
roles/common: Update apt in firewall task
Otherwise the buster-backports source might not be available, as
the nightly security upates use a different apt sources.list.
2019-10-05 12:00:08 +03:00
7551b803f6
roles/common: Use iptables 1.8.3 on Debian Buster
There is a bug in iptables 1.8.2 in Debian 10 "Buster" that causes
firewalld to fail when restoring rules. The bug has been fixed in
iptables 1.8.3, which is currently in buster-backports.

See: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=914694
2019-08-01 15:36:15 +03:00
0f512a5bf7
roles/common: Use blocks to tag children of dynamic tasks
When using dynamic includes, child tasks do not inherit tags from their
parents. You must tag the parent and each child task separately, or use
a block to group children and then apply a tag to a block.

See: https://docs.ansible.com/ansible/devel/porting_guides/porting_guide_2.5.html
2018-04-26 16:58:35 +03:00
7d950ade99
roles: Remove unreachable "packages" tags
After reörganizing for dynamic includes these tags will never be reached
because the children of dynamic includes do not inherit tags from their
parents as they did with static imports.
2018-04-26 16:31:06 +03:00
ab27caf877
roles/common: Use dynamic include_tasks for firewall
Use dynamic includes instead of static imports when you are running
tasks conditionally or using variable interpolation. The down side
is that you need to then tag the parent task as well as all child
tasks, as tags only apply to children of statically imported tasks.
2018-04-25 18:58:31 +03:00
a044fd2f55
roles/common: Add missing vim modelines 2018-04-25 18:55:22 +03:00
57120308dc
Update with_items loops to use new-ish "loop" keyword
Ansible 2.4 and 2.5 are moving away from specialized loop functions
and the old syntax will eventually be deprecated and removed. I did
not change the with_fileglob loops because I'm not sure about their
syntax yet.

See: https://docs.ansible.com/ansible/latest/user_guide/playbooks_loops.html
2018-04-02 15:52:51 +03:00
d155898bb1
Use new syntax for Jinj2 filters that are used as tests
Ansible 2.5.0 uses a new syntax for Jinja2 filters that are used as
tests.

See: https://docs.ansible.com/ansible/devel/porting_guides/porting_guide_2.5.html
2018-03-21 21:17:21 +02:00
948058151a
roles/common: Fix issues raised by ansible-lint
[ANSIBLE0010] Package installs should not use latest
2017-12-29 20:11:55 +02:00
b87f2e2fb0
roles/common: Use command module instead of shell
You should only use the "shell" module when you need shell functions
like flow control and redirects. Also, the "command" module is safer
because it is not affected by the user's environment.
2017-11-05 00:49:03 +02:00
b6a54ca4d1 roles/common: Reload firewalld instead of restart
There is no need to bounce the service, just reload it.
2017-11-05 00:27:44 +02:00
ff6253213a
roles/common: Rename "iptables" task to "firewall" 2017-09-26 14:32:21 +03:00