#!/bin/sh # # $FreeBSD$ # # Packages to install into the image we're creating. This is a deliberately # minimalist set, providing only the packages necessary to bootstrap further # package installation as specified via EC2 user-data. export VM_EXTRA_PACKAGES="ec2-scripts firstboot-freebsd-update firstboot-pkgs dual-dhclient amazon-ssm-agent" # Set to a list of third-party software to enable in rc.conf(5). export VM_RC_LIST="ec2_configinit ec2_fetchkey ec2_ephemeralswap ec2_loghostkey firstboot_freebsd_update firstboot_pkgs ntpd" # Build with a 3 GB UFS partition; the growfs rc.d script will expand # the partition to fill the root disk after the EC2 instance is launched. # Note that if this is set to G, we will end up with an GB disk # image since VMSIZE is the size of the UFS partition, not the disk which # it resides within. export VMSIZE=3072M # No swap space; the ec2_ephemeralswap rc.d script will allocate swap # space on EC2 ephemeral disks. (If they exist -- the T2 low-cost instances # and the C4 compute-optimized instances don't have ephemeral disks. But # it would be silly to bloat the image and increase costs for every instance # just for those two families, especially since instances ranging in size # from 1 GB of RAM to 60 GB of RAM would need different sizes of swap space # anyway.) export NOSWAP=YES vm_extra_pre_umount() { # The firstboot_pkgs rc.d script will download the repository # catalogue and install or update pkg when the instance first # launches, so these files would just be replaced anyway; removing # them from the image allows it to boot faster. chroot ${DESTDIR} env ASSUME_ALWAYS_YES=yes \ /usr/sbin/pkg delete -f -y pkg rm ${DESTDIR}/var/db/pkg/repo-*.sqlite # The size of the EC2 root disk can be configured at instance launch # time; expand our filesystem to fill the disk. echo 'growfs_enable="YES"' >> ${DESTDIR}/etc/rc.conf # EC2 instances use DHCP to get their network configuration. IPv6 # requires accept_rtadv. echo 'ifconfig_DEFAULT="SYNCDHCP accept_rtadv"' >> ${DESTDIR}/etc/rc.conf # Unless the system has been configured via EC2 user-data, the user # will need to SSH in to do anything. echo 'sshd_enable="YES"' >> ${DESTDIR}/etc/rc.conf # The AWS CLI tools are generally useful, and small enough that they # will download quickly; but users will often override this setting # via EC2 user-data. echo 'firstboot_pkgs_list="awscli"' >> ${DESTDIR}/etc/rc.conf # Enable IPv6 on all interfaces, and use DHCP on both IPv4 and IPv6. echo 'ipv6_activate_all_interfaces="YES"' >> ${DESTDIR}/etc/rc.conf echo 'dhclient_program="/usr/local/sbin/dual-dhclient"' >> ${DESTDIR}/etc/rc.conf # The EC2 console is output-only, so while printing a backtrace can # be useful, there's no point dropping into a debugger or waiting # for a keypress. echo 'debug.trace_on_panic=1' >> ${DESTDIR}/boot/loader.conf echo 'debug.debugger_on_panic=0' >> ${DESTDIR}/boot/loader.conf echo 'kern.panic_reboot_wait_time=0' >> ${DESTDIR}/boot/loader.conf # The console is not interactive, so we might as well boot quickly. echo 'autoboot_delay="-1"' >> ${DESTDIR}/boot/loader.conf echo 'beastie_disable="YES"' >> ${DESTDIR}/boot/loader.conf # EC2 has two consoles: An emulated serial port ("system log"), # which has been present since 2006; and a VGA console ("instance # screenshot") which was introduced in 2016. echo 'boot_multicons="YES"' >> ${DESTDIR}/boot/loader.conf # Some older EC2 hardware used a version of Xen with a bug in its # emulated serial port. It is not clear if EC2 still has any such # nodes, but apply the workaround just in case. echo 'hw.broken_txfifo="1"' >> ${DESTDIR}/boot/loader.conf # Load the kernel module for the Amazon "Elastic Network Adapter" echo 'if_ena_load="YES"' >> ${DESTDIR}/boot/loader.conf # Disable ChallengeResponseAuthentication according to EC2 # requirements. sed -i '' -e \ 's/^#ChallengeResponseAuthentication yes/ChallengeResponseAuthentication no/' \ ${DESTDIR}/etc/ssh/sshd_config # Use the NTP service provided by Amazon sed -i '' -e 's/^pool/#pool/' \ -e 's/^#server.*/server 169.254.169.123 iburst/' \ ${DESTDIR}/etc/ntp.conf # The first time the AMI boots, the installed "first boot" scripts # should be allowed to run: # * ec2_configinit (download and process EC2 user-data) # * ec2_fetchkey (arrange for SSH using the EC2-provided public key) # * growfs (expand the filesystem to fill the provided disk) # * firstboot_freebsd_update (install critical updates) # * firstboot_pkgs (install packages) touch ${DESTDIR}/firstboot rm -f ${DESTDIR}/etc/resolv.conf return 0 }