1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
|
#!/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="${VM_EXTRA_PACKAGES} ec2-scripts \
firstboot-freebsd-update firstboot-pkgs isc-dhcp44-client \
ebsnvme-id"
# Include the amazon-ssm-agent package in amd64 images, since some users want
# to be able to use it on systems which are not connected to the Internet.
# (It is not enabled by default, however.) This package does not exist for
# aarch64, so we have to be selective about when we install it.
if [ "${TARGET_ARCH}" = "amd64" ]; then
export VM_EXTRA_PACKAGES="${VM_EXTRA_PACKAGES} amazon-ssm-agent"
fi
# Set to a list of third-party software to enable in rc.conf(5).
export VM_RC_LIST="ec2_configinit ec2_fetchkey ec2_loghostkey firstboot_freebsd_update firstboot_pkgs ntpd dev_aws_disk"
# Build with a 4.9 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 <N>G, we will end up with an <N+1> GB disk
# image since VMSIZE is the size of the UFS partition, not the disk which
# it resides within.
export VMSIZE=5000m
# 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.
mount -t devfs devfs ${DESTDIR}/dev
chroot ${DESTDIR} ${EMULATOR} env ASSUME_ALWAYS_YES=yes \
/usr/sbin/pkg delete -f -y pkg
umount ${DESTDIR}/dev
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 spawn DHCPv6 via rtsold
echo 'ipv6_activate_all_interfaces="YES"' >> ${DESTDIR}/etc/rc.conf
echo 'rtsold_enable="YES"' >> ${DESTDIR}/etc/rc.conf
echo 'rtsold_flags="-M /usr/local/libexec/rtsold-M -a"' >> ${DESTDIR}/etc/rc.conf
# Turn off IPv6 Duplicate Address Detection; the EC2 networking
# configuration makes it unnecessary.
echo 'net.inet6.ip6.dad_count=0' >> ${DESTDIR}/etc/sysctl.conf
# Provide a script which rtsold can use to launch DHCPv6
mkdir -p ${DESTDIR}/usr/local/libexec
cat > ${DESTDIR}/usr/local/libexec/rtsold-M <<'EOF'
#!/bin/sh
/usr/local/sbin/dhclient -6 -nw -N -cf /dev/null $1
EOF
chmod 755 ${DESTDIR}/usr/local/libexec/rtsold-M
# 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
# Tell gptboot not to wait 3 seconds for a keypress which won't
# arrive either.
printf -- "-n\n" > ${DESTDIR}/boot.config
# The emulated keyboard attached to EC2 instances is inaccessible to
# users, and there is no mouse attached at all; disable to keyboard
# and the keyboard controller (to which the mouse would attach, if
# one existed) in order to save time in device probing.
echo 'hint.atkbd.0.disabled=1' >> ${DESTDIR}/boot/loader.conf
echo 'hint.atkbdc.0.disabled=1' >> ${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
# Use the "nda" driver for accessing NVMe disks rather than the
# historical "nvd" driver.
echo 'hw.nvme.use_nvd="0"' >> ${DESTDIR}/boot/loader.conf
# Disable KbdInteractiveAuthentication according to EC2 requirements.
sed -i '' -e \
's/^#KbdInteractiveAuthentication yes/KbdInteractiveAuthentication no/' \
${DESTDIR}/etc/ssh/sshd_config
# Use FreeBSD Update and Portsnap mirrors hosted in AWS
sed -i '' -e 's/update.FreeBSD.org/aws.update.FreeBSD.org/' \
${DESTDIR}/etc/freebsd-update.conf
sed -i '' -e 's/portsnap.FreeBSD.org/aws.portsnap.FreeBSD.org/' \
${DESTDIR}/etc/portsnap.conf
# Use the NTP service provided by Amazon
sed -i '' -e 's/^pool/#pool/' \
-e '1,/^#server/s/^#server.*/server 169.254.169.123 iburst/' \
${DESTDIR}/etc/ntp.conf
# Provide a map for accessing Elastic File System mounts
cat > ${DESTDIR}/etc/autofs/special_efs <<'EOF'
#!/bin/sh
if [ $# -eq 0 ]; then
# No way to know which EFS filesystems exist and are
# accessible to this EC2 instance.
exit 0
fi
# Provide instructions on how to mount the requested filesystem.
FS=$1
REGION=`fetch -qo- http://169.254.169.254/latest/meta-data/placement/availability-zone | sed -e 's/[a-z]$//'`
echo "-nfsv4,minorversion=1,oneopenown ${FS}.efs.${REGION}.amazonaws.com:/"
EOF
chmod 755 ${DESTDIR}/etc/autofs/special_efs
# 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 ${DESTDIR}/firstboot
if ! [ -z "${QEMUSTATIC}" ]; then
rm -f ${DESTDIR}/${EMULATOR}
fi
rm -f ${DESTDIR}/etc/resolv.conf
return 0
}
|
