#cloud-config ssh_genkeytypes: [ecdsa, ed25519] # upgrade system package_update: true package_upgrade: true # various dependencies packages: - ca-certificates - curl - gnupg - lsb-release - fail2ban - nginx - certbot - python3-certbot-nginx - iptables-persistent write_files: - path: /etc/iptables/rules.v4 permissions: 0644 owner: root:root content: | *filter :INPUT DROP [0:0] :FORWARD DROP [0:0] :OUTPUT ACCEPT [0:0] -A INPUT -i lo -j ACCEPT -A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT -A INPUT -m conntrack --ctstate INVALID -j DROP -A INPUT -p tcp -m tcp --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT -A INPUT -p tcp -m tcp --dport 8448 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT -A OUTPUT -o lo -j ACCEPT -A OUTPUT -m conntrack --ctstate ESTABLISHED -j ACCEPT -A OUTPUT -p tcp -m tcp --sport 22 -m conntrack --ctstate ESTABLISHED -j ACCEPT -A OUTPUT -p tcp -m tcp --dport 25 -j REJECT --reject-with icmp-port-unreachable COMMIT - path: /etc/systemd/journald.conf.d/size.conf permissions: 0644 owner: root:root content: | [Journal] SystemMaxUse=250M SystemMaxFileSize=50M - path: /etc/fstab append: true content: | /swapfile swap swap defaults 0 0 runcmd: - 'iptables-restore < /etc/iptables/rules.v4' - [systemctl, enable, --now, fail2ban] - 'fallocate -l 3G /swapfile' - 'chmod 600 /swapfile' - 'mkswap /swapfile' - 'swapon /swapfile' - [curl, https://gitea.it/Unitoo/dot-files/raw/branch/master/ssh/etc/ssh/sshd_config, --output, /etc/ssh/sshd_config.d/99-hardening.conf] - [systemctl, restart, ssh] - [curl, https://gitea.it/Unitoo/dot-files/raw/branch/master/modprobe/etc/modprobe.d/disable-network-filesystems.conf, --output, /etc/modprobe.d/disable-network-filesystems.conf] - [curl, https://gitea.it/Unitoo/dot-files/raw/branch/master/modprobe/etc/modprobe.d/disable-rare-filesystems.conf, --output, /etc/modprobe.d/disable-rare-filesystems.conf] - [curl, https://gitea.it/Unitoo/dot-files/raw/branch/master/modprobe/etc/modprobe.d/disable-rare-protocols.conf, --output, /etc/modprobe.d/disable-rare-protocols.conf] - [curl, https://gitea.it/Unitoo/dot-files/raw/branch/master/modprobe/etc/modprobe.d/disable-vivid.conf, --output, /etc/modprobe.d/disable-vivid.conf] - [curl, https://gitea.it/Unitoo/dot-files/raw/branch/master/sysctl/etc/sysctl.conf, --output, /etc/sysctl.d/99-hardening.conf] - [sysctl, -p] - [timedatectl, set-timezone, Europe/Rome]