fail2ban: BAN docker services for security (for Docker Host that installed fail2ban)

fail2ban-for-host.sh

# INSERT fail2ban FORWARD for Docker host
sudo iptables -I FORWARD -j f2b-postgres

# DELETE fail2ban FORWARD for Docker host
sudo iptables -D FORWARD -j f2b-postgres

# Save
sudo iptables-save

postgres-filter.conf

# /etc/fail2ban/filter.d/postgres.conf
[Definition]
failregex = \{<HOST>\} .+? FATAL:  password authentication failed for user .+$

postgres-jail.conf

# /etc/fail2ban/jail.d/postgres.conf
[postgresql]
enabled = true
filter = postgres
logpath = /path/to/docker/postgres/data/log/postgresql*.log
banaction = iptables-allports # or iptables-multiport, nftables-*, etc...
maxretry = 3
findtime = 1200
bantime = 86400
port = 5432
usedns = raw
mode = aggressive
backend = polling # fail2ban can't track docker generated files...
ignoreip = 192.168.0.0/16 #for example

postgresql.conf

log_destination = 'stderr'
logging_collector = on
log_directory = 'log'
log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log'
log_connections = on
log_line_prefix = '%m {%h} [%p] '
log_timezone = 'Etc/UTC' # Do not change timezone or fail2ban will not collect failed data.