xref: /freebsd/release/tools/ec2.conf (revision bdd1243df58e60e85101c09001d9812a789b6bc4)
1#!/bin/sh
2#
3# $FreeBSD$
4#
5
6# Packages to install into the image we're creating.  This is a deliberately
7# minimalist set, providing only the packages necessary to bootstrap further
8# package installation as specified via EC2 user-data.
9export VM_EXTRA_PACKAGES="${VM_EXTRA_PACKAGES} ec2-scripts \
10	firstboot-freebsd-update firstboot-pkgs isc-dhcp44-client \
11	ebsnvme-id"
12
13# Include the amazon-ssm-agent package in amd64 images, since some users want
14# to be able to use it on systems which are not connected to the Internet.
15# (It is not enabled by default, however.)  This package does not exist for
16# aarch64, so we have to be selective about when we install it.
17if [ "${TARGET_ARCH}" = "amd64" ]; then
18	export VM_EXTRA_PACKAGES="${VM_EXTRA_PACKAGES} amazon-ssm-agent"
19fi
20
21# Set to a list of third-party software to enable in rc.conf(5).
22export VM_RC_LIST="ec2_configinit ec2_fetchkey ec2_loghostkey firstboot_freebsd_update firstboot_pkgs ntpd dev_aws_disk ec2_ephemeral_swap"
23
24# Build with a 4.9 GB partition; the growfs rc.d script will expand
25# the partition to fill the root disk after the EC2 instance is launched.
26# Note that if this is set to <N>G, we will end up with an <N+1> GB disk
27# image since VMSIZE is the size of the filesystem partition, not the disk
28# which it resides within.
29export VMSIZE=5000m
30
31# No swap space; the ec2_ephemeralswap rc.d script will allocate swap
32# space on EC2 ephemeral disks.  (If they exist -- the T2 low-cost instances
33# and the C4 compute-optimized instances don't have ephemeral disks.  But
34# it would be silly to bloat the image and increase costs for every instance
35# just for those two families, especially since instances ranging in size
36# from 1 GB of RAM to 60 GB of RAM would need different sizes of swap space
37# anyway.)
38export NOSWAP=YES
39
40vm_extra_pre_umount() {
41	# The firstboot_pkgs rc.d script will download the repository
42	# catalogue and install or update pkg when the instance first
43	# launches, so these files would just be replaced anyway; removing
44	# them from the image allows it to boot faster.
45	mount -t devfs devfs ${DESTDIR}/dev
46	chroot ${DESTDIR} ${EMULATOR} env ASSUME_ALWAYS_YES=yes \
47		/usr/sbin/pkg delete -f -y pkg
48	umount ${DESTDIR}/dev
49	rm ${DESTDIR}/var/db/pkg/repo-*.sqlite
50
51	# The size of the EC2 root disk can be configured at instance launch
52	# time; expand our filesystem to fill the disk.
53	echo 'growfs_enable="YES"' >> ${DESTDIR}/etc/rc.conf
54
55	# EC2 instances use DHCP to get their network configuration.  IPv6
56	# requires accept_rtadv.
57	echo 'ifconfig_DEFAULT="SYNCDHCP accept_rtadv"' >> ${DESTDIR}/etc/rc.conf
58
59	# Unless the system has been configured via EC2 user-data, the user
60	# will need to SSH in to do anything.
61	echo 'sshd_enable="YES"' >> ${DESTDIR}/etc/rc.conf
62
63	# The AWS CLI tools are generally useful, and small enough that they
64	# will download quickly; but users will often override this setting
65	# via EC2 user-data.
66	echo 'firstboot_pkgs_list="devel/py-awscli"' >> ${DESTDIR}/etc/rc.conf
67
68	# Enable IPv6 on all interfaces, and spawn DHCPv6 via rtsold
69	echo 'ipv6_activate_all_interfaces="YES"' >> ${DESTDIR}/etc/rc.conf
70	echo 'rtsold_enable="YES"' >> ${DESTDIR}/etc/rc.conf
71	echo 'rtsold_flags="-M /usr/local/libexec/rtsold-M -a"' >> ${DESTDIR}/etc/rc.conf
72
73	# Turn off IPv6 Duplicate Address Detection; the EC2 networking
74	# configuration makes it unnecessary.
75	echo 'net.inet6.ip6.dad_count=0' >> ${DESTDIR}/etc/sysctl.conf
76
77	# Provide a script which rtsold can use to launch DHCPv6
78	mkdir -p ${DESTDIR}/usr/local/libexec
79	cat > ${DESTDIR}/usr/local/libexec/rtsold-M <<'EOF'
80#!/bin/sh
81
82/usr/local/sbin/dhclient -6 -nw -N -cf /dev/null $1
83EOF
84	chmod 755 ${DESTDIR}/usr/local/libexec/rtsold-M
85
86	# The EC2 console is output-only, so while printing a backtrace can
87	# be useful, there's no point dropping into a debugger or waiting
88	# for a keypress.
89	echo 'debug.trace_on_panic=1' >> ${DESTDIR}/boot/loader.conf
90	echo 'debug.debugger_on_panic=0' >> ${DESTDIR}/boot/loader.conf
91	echo 'kern.panic_reboot_wait_time=0' >> ${DESTDIR}/boot/loader.conf
92
93	# The console is not interactive, so we might as well boot quickly.
94	echo 'autoboot_delay="-1"' >> ${DESTDIR}/boot/loader.conf
95	echo 'beastie_disable="YES"' >> ${DESTDIR}/boot/loader.conf
96
97	# Tell gptboot not to wait 3 seconds for a keypress which won't
98	# arrive either.
99	printf -- "-n\n" > ${DESTDIR}/boot.config
100
101	# The emulated keyboard attached to EC2 instances is inaccessible to
102	# users, and there is no mouse attached at all; disable to keyboard
103	# and the keyboard controller (to which the mouse would attach, if
104	# one existed) in order to save time in device probing.
105	echo 'hint.atkbd.0.disabled=1' >> ${DESTDIR}/boot/loader.conf
106	echo 'hint.atkbdc.0.disabled=1' >> ${DESTDIR}/boot/loader.conf
107
108	# EC2 has two consoles: An emulated serial port ("system log"),
109	# which has been present since 2006; and a VGA console ("instance
110	# screenshot") which was introduced in 2016.
111	echo 'boot_multicons="YES"' >> ${DESTDIR}/boot/loader.conf
112
113	# Some older EC2 hardware used a version of Xen with a bug in its
114	# emulated serial port.  It is not clear if EC2 still has any such
115	# nodes, but apply the workaround just in case.
116	echo 'hw.broken_txfifo="1"' >> ${DESTDIR}/boot/loader.conf
117
118	# Load the kernel module for the Amazon "Elastic Network Adapter"
119	echo 'if_ena_load="YES"' >> ${DESTDIR}/boot/loader.conf
120
121	# Use the "nda" driver for accessing NVMe disks rather than the
122	# historical "nvd" driver.
123	echo 'hw.nvme.use_nvd="0"' >> ${DESTDIR}/boot/loader.conf
124
125	# Disable KbdInteractiveAuthentication according to EC2 requirements.
126	sed -i '' -e \
127		's/^#KbdInteractiveAuthentication yes/KbdInteractiveAuthentication no/' \
128		${DESTDIR}/etc/ssh/sshd_config
129
130	# Use FreeBSD Update and Portsnap mirrors hosted in AWS
131	sed -i '' -e 's/update.FreeBSD.org/aws.update.FreeBSD.org/' \
132		${DESTDIR}/etc/freebsd-update.conf
133	sed -i '' -e 's/portsnap.FreeBSD.org/aws.portsnap.FreeBSD.org/' \
134		${DESTDIR}/etc/portsnap.conf
135
136	# Use the NTP service provided by Amazon
137	sed -i '' -e 's/^pool/#pool/' \
138		-e '1,/^#server/s/^#server.*/server 169.254.169.123 iburst/' \
139		${DESTDIR}/etc/ntp.conf
140
141	# Provide a map for accessing Elastic File System mounts
142	cat > ${DESTDIR}/etc/autofs/special_efs <<'EOF'
143#!/bin/sh
144
145if [ $# -eq 0 ]; then
146        # No way to know which EFS filesystems exist and are
147        # accessible to this EC2 instance.
148        exit 0
149fi
150
151# Provide instructions on how to mount the requested filesystem.
152FS=$1
153REGION=`fetch -qo- http://169.254.169.254/latest/meta-data/placement/availability-zone | sed -e 's/[a-z]$//'`
154echo "-nfsv4,minorversion=1,oneopenown ${FS}.efs.${REGION}.amazonaws.com:/"
155EOF
156	chmod 755 ${DESTDIR}/etc/autofs/special_efs
157
158	# The first time the AMI boots, the installed "first boot" scripts
159	# should be allowed to run:
160	# * ec2_configinit (download and process EC2 user-data)
161	# * ec2_fetchkey (arrange for SSH using the EC2-provided public key)
162	# * growfs (expand the filesystem to fill the provided disk)
163	# * firstboot_freebsd_update (install critical updates)
164	# * firstboot_pkgs (install packages)
165	touch ${DESTDIR}/firstboot
166
167	# Any EC2 ephemeral disks seen when the system first boots will
168	# be "new" disks; there is no "previous boot" when they might have
169	# been seen and used already.
170	touch ${DESTDIR}/var/db/ec2_ephemeral_diskseen
171
172	if ! [ -z "${QEMUSTATIC}" ]; then
173		rm -f ${DESTDIR}/${EMULATOR}
174	fi
175	rm -f ${DESTDIR}/etc/resolv.conf
176
177	return 0
178}
179