policyd-rate-limit 0.3.2

Postfix rate limit policy server implemented in Python3.

Postfix policyd server allowing to limit the number of mail accepted by postfix over several time periods, by sasl usernames and/or ip addresses.

Installation

First, create the user that will run the daemon and its home directory:

mkdir -p /var/lib/policyd-rate-limit
useradd policyd-rate-limit -d /var/lib/policyd-rate-limit

Depending of the backend storage you planning to use, you may need to install additional packages. (The default settings use the sqlite3 bakends and do not need extra packages).

• mysqldb (sudo apt-get install python3-mysqldb on debian like systems) for the mysql backend.

• psycopg2 (sudo apt-get install python3-psycopg2 on debian like systems) fot the postgreysql backend

Install with pip:

sudo pip3 install policyd-rate-limit

or from source code:

sudo make install

This will install the policyd_rate_limit module, the policyd-rate-limit binary, copy the default config to /etc/policyd-rate-limit.conf if the file do not exists, copy an init script to /etc/init.d/policyd-rate-limit and an unit file to /etc/systemd/system/policyd-rate-limit.service.

After the installation, you may need to run sudo systemctl daemon-reload for make the unit file visible by systemd.

You should ran policyd-rate-limit --clean on a regular basis to delete old records from the database. It could be wise to put it in a daily cron, for example:

0 0 * * * policyd-rate-limit /usr/local/bin/policyd-rate-limit --clean >/dev/null

Settings

policyd-rate-limit search for its config first in ~/.config/policyd-rate-limit.conf If not found, then in /etc/policyd-rate-limit.conf, and if not found use the default config.

• debug: make policyd-rate-limit output to stderr all of its exanges with postfix. The default is True.

• user: The user policyd-rate-limit will use to drop privileges. The default is "policyd-rate-limit".

• group: The group policyd-rate-limit will use to drop privileges. The defaut is "policyd-rate-limit".

• pidfile: path where the program will try to write its pid to. The default is "/var/run/policyd-rate-limit/policyd-rate-limit.pid". policyd-rate-limit will try to create the parent directory and chown it if it do not exists.

• mysql_config: The config to connect to a mysql server

• pgsql_config: The config to connect to a postgreysql server

• sqlite_config: The config to connect to a sqlite3 database.

• backend: Which data backend to use. Possible values are 0 for sqlite3, 1 for mysql and 2 for postgreysql. The default is 0, use the sqlite3 backend.

• SOCKET: The socket to bind to. Can be a path to an unix socket or a couple (ip, port). The default is "/var/spool/postfix/ratelimit/policy". policyd-rate-limit will try to create the parent directory and chown it if it do not exists.

• socket_permission: Permissions on the unix socket (if unix socket used). The default is 0o666.

• limits: A list of couple (number of emails, number of seconds). If one of the element of the list is exeeded (more than ‘number of emails’ on ‘number of seconds’ for an ip address or an sasl username), postfix will return a temporary failure.

• limit_by_sasl: Apply limits by sasl usernames. The default is True.

• limit_by_ip: Apply limits by ip addresses. The default is False.

• limited_netword: A list of ip networks in cidr notation on which limits are applied. An empty list is equal to limit_by_ip = False, put "0.0.0.0/0" and ::/0 for every ip addresses.

Postfix settings

/etc/postfix/main.cf:

smtpd_recipient_restrictions =
    ...
    check_policy_service unix:ratelimit/policy
    ...