Commit Graph

148 Commits

Author SHA1 Message Date
479127a5e4
roles/common: Fix nftables handler in Debian firewall
We used to use reload, but now the idempotent thing to do is to use
restart instead of reload.
2021-09-07 15:43:33 +03:00
b5ea575d8d
roles/common: Always restart nftables service
The "reload" capability only exists on Ubuntu, and it is exactly
the same as the "restart" functionality.
2021-08-01 14:23:00 +03:00
98cc3a8c2e
Add nginx filter for fail2ban
Some hosts can use fail2ban's nginx-botsearch filter to ban anyone
making requests to non-existent files like wp-login.php. There is
no reason to request such files naively and anyone found doing so
can be banned immediately.

In theory I should report them to AbuseIPDB.com, but that will take
a little more wiring up.
2021-08-01 09:56:43 +03:00
a67d901641
roles/common: Use AbuseIPDB.com list in nftables
For now I am still manually updating this, as we can only hit their
API five times per day, so it is not possible to have each host get
the list themselves every day with our one API key.
2021-07-31 21:46:50 +03:00
debcb21161
roles/common: Install curl for Abuse.ch update scripts 2021-07-29 10:24:32 +03:00
8dd7663b3c
roles/common: Use Abuse.ch's SSL Blacklist in nftables
This adds Abuse.sh's list of IPs using blacklisted SSL certificates
to nftables. These IPs are high confidence indicators of compromise
and we should not route them. The list is updated daily by a systemd
timer.

See: https://sslbl.abuse.ch/blacklist/
2021-07-29 10:16:00 +03:00
cba2a7a996
roles/common: Fix nftables in Debian firewall
The previous commit meant to move the service start, not the config
copying task.
2021-07-29 10:10:04 +03:00
197bdf7666
roles/common: Start nftables service later
We should only try to start the nftables service after we finish
copying all the config files just in case there is some unclean
state in one of them. On a first run this shouldn't matter, but
after nftables and some abuse list update scripts have run this
can happen (mostly in testing!).
2021-07-29 10:05:15 +03:00
46fc2ce3d4
roles/common: Move cleanup to a one-off play
We only need to run this once on existing hosts that are using the
old firewalld/ipsets setup before applying the new nftables config.
2021-07-29 10:00:30 +03:00
b4d50166f4
roles/common: Fix loop in firewall cleanup 2021-07-28 23:46:53 +03:00
af6c3dd12a
roles/common: Update cache in firewall playbook
cron-apt updates the system against the security-only databases at
night so many packages are "missing" unless you run apt update. We
need to update the cache on all apt tasks actually because I might
be running them by their tag and they currently only get updated at
the beginning of the playbook.
2021-07-28 14:46:58 +03:00
b66c724109
roles/common: Use nftables on Ubuntu 20.04 as well
This mostly copies the Debian 11 nftables setup and includes a play
to clean up the old firewalld settings, timers, etc.
2021-07-28 14:18:41 +03:00
a74d6dfc08
roles/common: Don't overwrite spamhaus nft sets
The ones in this repo are only placeholders that get updated by the
update-spamhaus-nftables service, so we shouldn't overwrite them if
they exist.
2021-07-27 22:01:57 +03:00
9bba0d96bb
roles/common: Add initial support for nftables on Debian 11
I will try using nftables directly instead of via firewalld as of
Debian 11 as it is the replacement for the iptables/ipset stack in
recent years and is easier to work with.

This also includes a systemd service, timer, and script to update
the spamhaus DROP lists as nftables sets.

Still need to add fail2ban support.
2021-07-26 13:09:41 +03:00
38c333045b
roles/common: bring Ubuntu firewall changes to Debian 11
Note that there is currently an issue loading the spamhaus rules on
Debian 11 when using ipsets with firewalld and the nftables backend.
The bug is apparently caused by overlapping CIDR segments, and the
solution appears to be that we need to manually aggregate them with
a tool like aggregate6 (Python).

See: https://bugzilla.redhat.com/show_bug.cgi?id=1836571
See: https://wiki.fysik.dtu.dk/it/Linux_firewall_configuration#using-ipsets-in-firewalld-on-rhel-centos-8
See: https://github.com/job/aggregate6
2021-07-24 23:09:33 +03:00
d4ede33099
roles/common: Don't configure apt sources on ARM
I was using this on Ubuntu, but might as well bring it here too so
that I can run Debian on Scaleway's ARM instances, for example.
2021-07-24 22:32:20 +03:00
d7c34a30a3
roles/common: Add Spamhaus DROP lists to firewalld ipsets
This configures the recommended DROP, EDROP, and DROPv6 lists from
Spamhaus as ipsets in firewalld. First we copy an empty placeholder
ipset to seed firewalld, then we use a shell script to download the
real lists and activate them. The same shell script is run daily as
a service (update-spamhaus-lists.service) by a systemd timer.

I am strictly avoiding any direct ipset commands here because I want
to make sure that this works on older hosts where ipsets is used as
well as newer hosts that have moved to nftables such as Ubuntu 20.04.
So far I have tested this on Ubuntu 16.04, 18.04, and 20.04, but ev-
entually I need to abstract the tasks and run them on CentOS 7+ as
well.

See: https://www.spamhaus.org/drop/
2021-07-21 09:34:51 +03:00
63a836e2a7
roles/common: Update Tarsnap GPG key
Apparently this changed since I last ran the tarsnap task.
2021-02-13 12:57:17 +02:00
dd2f65947d
roles/common: Update list of abusive IP addresses
This comes from the AbuseIPDB with a confidence level of 95%. I use
the following command to download and sort the IPs:

    $ curl -G https://api.abuseipdb.com/api/v2/blacklist -d \
      confidenceMinimum=95 -H "Key: $ABUSEIPDB_API_KEY" \
      -H "Accept: text/plain" | sort | sed -e '/:/w /tmp/ipv6.txt' \
      -e '/:/d' > /tmp/ipv4.txt

I manually add the XML formatting to each file and run them through
tidy:

    $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv4.xml
    $ tidy -xml -utf8 -m -iq -w 0 roles/common/files/abusers-ipv6.xml
2020-11-06 15:44:57 +02:00
f4b104953c
roles/common: Use correct Ansible version comparison
The major version is "16", not "16.04".
2020-07-27 14:23:58 +03:00
72b8b193b5
Remove support for Debian 9 and Ubuntu 16.04 2020-07-14 09:45:33 +03:00
5282154d7d
roles/common: Disable Canonical spam in MOTD 2020-06-25 21:12:00 +03:00
40ac858d60 roles/common: Ignore errors removing snaps
If the snap binary doesn't even exist then it means we've probably
already run this playbook and removed all installed snaps as well.
2020-06-08 12:15:29 +03:00
ba3004ef2b roles/common: Don't run rc.local task on Ubuntu 20.04
We haven't actually used rc.local since Ubuntu 16.04. Now anything
that we need to run at boot we can do with systemd anyways.
2020-06-08 12:15:29 +03:00
ef6ce2335e roles/common: Remove systemd-journald drop-in
Older Ubuntus originally didn't use a persistent journal, which was
somewhat of a surprise when looking at logs after a few months. Now
this does not seem to be an issue since Ubuntu 18.04. As for CentOS
I do not use that distro here so I don't need to care.
2020-06-08 12:15:29 +03:00
96f62a17d1 roles/common: Use nftables backend in firewalld on Ubuntu 20.04
The nftables backend should be more performant and flexible. I had
been planning to use it on Ubuntu 18.04 and Debian 10 as well, but
there were issues with the specific versions used in those distros.

See: https://firewalld.org/2018/07/nftables-backend
2020-06-08 12:15:29 +03:00
29bbc14068 roles/common: Remove ufw from Ubuntu systems
We never used this simple firewall utility and in at least one case
a user on the server tried to use it and messed up the rules I had
set via firewalld.
2020-06-08 12:15:29 +03:00
7288a85e72 roles/common: Remove snaps on Ubuntu 20.04
The list of pre-installed snaps and system packages is different on
Ubuntu 20.04 than it was in previous LTS releases.

See: https://www.kevin-custer.com/blog/disabling-snaps-in-ubuntu-20-04/
2020-06-08 12:15:29 +03:00
ed2e0efd9c
roles/common: Actually remove annoying Ubuntu motd spam 2020-04-24 22:37:50 +03:00
03254d6aae
roles/common: Use normal tarsnap GPG packaging key 2020-03-16 18:03:53 +02:00
2dc195b33c
Use version() instad of version_compare()
This changed in Ansible 2.5 apparently.

See: https://docs.ansible.com/ansible/latest/user_guide/playbooks_tests.html
2020-03-09 15:20:51 +02:00
e4c3376383
roles/common: Fix logic in enabling individual calls in firewalld 2019-12-10 13:45:00 +02:00
2631f76c6d
roles/common: Use iptables backend for firewalld on Debian
For some reason the nftables set support in firewalld doesn't seem
to be working. I see that sets (aka ipsets in nftables lingo) are
created, but they are empty. For now I will just leave these tasks
as they are to revert the behavior on current hosts (should do no
change on new installed, as the regexp won't match).
2019-10-26 19:34:25 +02:00
919fbbbcd9
roles/common: Make sure fail2ban is started 2019-10-26 17:14:28 +02:00
4710ee6f07
roles/common: Bump version checks to Ubuntu 16.04 2019-10-26 16:40:14 +02:00
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
cbdd779af0
roles/common: Remove lzop and lrzip from packages
zstd is a much better all-purpose compression utility.
2019-09-15 13:23:52 +03:00
4faeb79b5c
roles/common: Add zstd to base packages 2019-09-14 20:36:40 +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
c148da73e7
roles/common: Use experimental Tarsnap on Debian buster
Tarsnap currently provides experimental packages for Debian Buster.

See: https://www.tarsnap.com/pkg-deb.html#experimental
2019-07-19 12:07:27 +03:00
03e2abc4fb roles/common: Install gnupg2 on Debian
Needed by Ansible to add and verify apt package signing keys.
2019-07-07 15:52:25 +03:00
12b6f3aaa2
roles/common: Don't ignore errors on Tarsnap key add
It turns out that I had the wrong key ID so it's no wonder this was
failing...
2019-07-07 15:51:04 +03:00
704b02ce0a
roles/common: Fix tarsnap package key
For some reason the key ID I had here was wrong. According to the
Tarsnap website the key ID is 0x6D97F5A4CA38CF33.

ee: https://www.tarsnap.com/pkg-deb.html
2019-07-07 15:49:45 +03:00