aboutsummaryrefslogtreecommitdiff
path: root/bootstrap
blob: 0d17ba11317a176750536ccd794a45b4735556d2 (plain)
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
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
#! /usr/bin/env bash

# Bootstrap build2 buildos.
#
# Assumptions/expectations:
#
# - host debootstrap/debian-archive-keyring matching release
#
# - /btrfs/<user> is a btrfs directory where the current user can create
#   snapshots
#
# - sudo is passwordless (used to run debootstrap, systemd-nspawn, etc)
#
# Options:
#
# --stage <num>
#   Jump straigh to stage <num> by clonning the previous stage snapshot.
#   Stages are:
#
#   1 - bootstrap phase 1
#   2 - bootstrap phase 2
#   3 - setup
#   4 - create footfs
#   5 - create kernel image and initrd
#
usage="usage: $0"

id="$(id -un)"
btrfs=/btrfs
release="unstable"
mirror="https://deb.debian.org/debian/"
passwd="123"                 #@@ TMP root passwd.
macaddr="de:ad:be:ef:b8:da"  # Mac address for testing.

root="$btrfs/$id/buildos"

owd="$(pwd)"
trap "{ cd '$owd'; exit 1; }" ERR
set -o errtrace # Trap in functions.

function info () { echo "$*" 1>&2; }
function error () { info "$*"; exit 1; }

stage="1"
stage_max="5"

while [ "$#" -gt 0 ]; do
  case "$1" in
    --stage)
      shift
      stage="$1"
      shift
      ;;
    -*)
      error "unknown option: $1"
      ;;
    *)
      break
      ;;
  esac
done

if [ "$stage" -lt "1" -o "$stage" -gt "$stage_max" ]; then
  error "invalid stage number $stage"
fi

# Btrfs subvolume manipulation.
#
function subvol_delete () # <path>
{
  # The subvol show (just as list) needs root.
  #
  if sudo btrfs subvol show "$1" 1>/dev/null 2>&1; then
    btrfs property set -ts "$1" ro false
    btrfs subvol delete "$1"
  fi
}

function subvol_create () # <path>
{
  btrfs subvol create "$@"
}

function subvol_snapshot () # [-r] <src-path> <dst-path>
{
  btrfs subvol snapshot "$@"
}

# Clean up the working subvolume and all the snapshots starting from the
# requested stage. Also, if stage is not 1, then restore the working subvolume
# from the previous stage snapshot.
#
subvol_delete "$root"

for i in $(seq "$stage" "$stage_max"); do
  subvol_delete "$root-$i"
done

if [ "$stage" -gt "1" ]; then
  i="$(($stage - 1))"
  info "restoring working subvolume from stage $i snapshot"
  subvol_snapshot "$root-$i" "$root"
fi

# Spawn a systemd namespace container (systemd-nspawn)
#
function nspawn () # <systemd-nspawn-args>
{
  sudo systemd-nspawn --register=no -D "$root" "$@"

  # systemd-nspawn may create the /var/lib/machines subvolume which prevents
  # the deletion of the containing submodule. So we clean it up.
  #
  if sudo btrfs subvol show "$root/var/lib/machines" 1>/dev/null 2>&1; then
    sudo btrfs subvol delete "$root/var/lib/machines"
  fi
}

# (Over)write or append to a file in the installation root, for example:
#
# write <<<'localhost' /etc/hostname
#
function write () # <path>
{
  sudo tee "$root$1" >/dev/null
}

function append () # <path>
{
  sudo tee -a "$root$1" >/dev/null
}

# Stage 1: debootstrap, phase 1.
#
if [ "$stage" -eq "1" ]; then

  subvol_create "$root"

  # Notes:
  #
  #  - systemd-container seems to be required by host systemd-nspawn.
  #
  pkgs="locales,systemd-container"

  pkgs+=",linux-image-amd64,irqbalance,pciutils"

  pkgs+=",hdparm,btrfs-progs"

  pkgs+=",net-tools,iproute2,iptables,isc-dhcp-client"
  pkgs+=",ifupdown,bridge-utils,dnsmasq,ntp,postfix"
  pkgs+=",iputils-ping,wget,curl"

  pkgs+=",less"

  sudo debootstrap \
    --foreign \
    --arch=amd64 \
    --merged-usr \
    --variant=minbase \
    --include="$pkgs" \
    "$release" "$root" "$mirror"

  # Post-phase 1 fixups.
  #

  # Set the initial hostname to '(none)'. This value is detected and
  # overriden by /sbin/dhclient-script if the DHCP server sends host-name.
  #
  write <<<'(none)' /etc/hostname

  # Set timezone to UTC (picked up by tzdata package during stage 2).
  #
  write <<<'Etc/UTC' /etc/timezone

  subvol_snapshot -r "$root" "$root-1"
fi

# Stage 2: debootstrap, phase 2.
#
if [ "$stage" -le "2" ]; then

  # Create a bootstrap script that will finish the bootstrap from within the
  # installation via systemd-nspawn.
  #
  sudo mkdir "$root/bootstrap"

  write <<EOF /bootstrap/bootstrap
#!/bin/bash

trap "exit 1" ERR

set -x

# Hack around systemd bug#79306 (changes /etc/localtime) by removing it now
# and making readonly below.
#
rm /etc/localtime

# Both nspawn and debootstrap try to mount /proc /sys (Debian bug#840372).
#
mkdir /tmp/proc /tmp/sys
mount --move /proc /tmp/proc
mount --move /sys /tmp/sys

# Run second stage of debootstrap.
#
/debootstrap/debootstrap --second-stage

rm -f /etc/localtime
cp /usr/share/zoneinfo/UTC /etc/localtime
chattr +i /etc/localtime

# Change /etc/os-release, /etc/issue, /etc/motd.
#
cat <<EOF1 >/etc/os-release
NAME="Build OS"
VERSION="0.5.0"
ID=buildos
ID_LIKE=debian
PRETTY_NAME="Build OS 0.5.0 (Based on Debian)"
VERSION_ID="0.5"
HOME_URL="https://build2.org/"
SUPPORT_URL="https://lists.build2.org/"
BUG_REPORT_URL="https://lists.build2.org/"
EOF1

cat <<EOF1 >/etc/issue
Build OS 0.5.0 (Based on Debian) \n \l

EOF1

cat <<EOF1 >/etc/motd
Welcome to Build OS 0.5.0 (https://build2.org)!

EOF1

# Set root password.
#
chpasswd <<<'root:$passwd'

# Enable IPv4 forwarding (used for private bridge NAT).
#
sed -i -e 's/^# *\(net.ipv4.ip_forward\).*/\1=1/' /etc/sysctl.conf

# Setup locale. We only support en_US.UTF-8.
#
sed -i -e 's/^# *\(en_US.UTF-8\)/\1/' /etc/locale.gen
locale-gen --purge

cat <<EOF1 >/etc/default/locale
LANG="en_US.UTF-8"
LANGUAGE="en_US:en"
EOF1

EOF
  sudo chmod u+x "$root/bootstrap/bootstrap"

  # Notes:
  #
  # - Failed to create directory .../sys/fs/selinux: Read-only file system is
  #   harmless and fixed upstream (systemd issue#3748).
  #
  nspawn /bootstrap/bootstrap

  subvol_snapshot -r "$root" "$root-2"
fi

# Stage 3: setup.
#
if [ "$stage" -le "3" ]; then

  # Create the setup script/service that will finish the setup from within the
  # installation via systemd-nspawn --boot.
  #
  sudo mkdir -p "$root/bootstrap"
  write <<EOF /bootstrap/setup
#!/bin/bash

trap "exit 1" ERR

set -x

# Clean up package cache.
#
apt-get clean

# Clean up /bootstrap.
#
rm /usr/lib/systemd/system/default.target.wants/setup.service
rm /usr/lib/systemd/system/setup.service
rm -r /bootstrap

# Shutdown the container from within.
#
systemctl poweroff

EOF
  sudo chmod u+x "$root/bootstrap/setup"

  # Note that when started via systemd-nspawn, we get /dev/console, not
  # /dev/tty0.
  #
  write <<EOF /usr/lib/systemd/system/setup.service
[Unit]
Description=Setup Service
After=default.target
Conflicts=console-getty.service

[Service]
Type=idle
TimeoutStartSec=infinity
RemainAfterExit=true
ExecStart=/bootstrap/setup
StandardInput=tty-force
StandardOutput=inherit
StandardError=inherit
TTYPath=/dev/console
TTYReset=yes
TTYVHangup=yes

[Install]
WantedBy=default.target
EOF

  sudo mkdir -p "$root/usr/lib/systemd/system/default.target.wants"
  sudo ln -sf "$root/usr/lib/systemd/system/setup.service" \
    "$root/usr/lib/systemd/system/default.target.wants/setup.service"

  nspawn --boot

  subvol_snapshot -r "$root" "$root-3"
fi

# Stage 4: generate rootfs.
#
if [ "$stage" -le "4" ]; then

  # Note that there is also initramfs image that is embedded into kernel. In
  # Debian it contains just /dev/console and /root/.
  #
  # Quite a few files/directories are only accessible by root (e.g., /root) so
  # we run under sudo.
  #
  cd "$root"

  root_dirs="dev etc mnt root usr var"
  root_links="bin sbin lib lib32 lib64"

  info "generating buildos-rootfs.cpio.gz..."
  sudo find $root_dirs $root_links -print0 | \
    sudo cpio --null -o -H newc | \
    gzip -9 > "$owd/buildos-rootfs.cpio.gz"

  cd "$owd"

  subvol_snapshot -r "$root" "$root-4"
fi

# Stage 5: generate initrd.
#
if [ "$stage" -le "5" ]; then

  # @@ TODO: init location
  #
  sudo cp -f ./init "$root/"

  info "generating buildos-init.cpio.gz..."
  sudo echo 'init' | \
    sudo cpio -o -H newc | \
    gzip -9 > "$owd/buildos-init.cpio.gz"

  cat buildos-rootfs.cpio.gz buildos-init.cpio.gz >buildos-initrd

  # Copy the kernel image next to the initramfs for convenience.
  #
  cp "$root/vmlinuz" buildos-image

  subvol_snapshot -r "$root" "$root-5"
fi

# Test.
#
# To test PXE boot, replace -kernel/-initrd with '-boot n'.
#
sudo kvm \
  -m 8G \
  -netdev 'tap,id=net0,script=./qemu-ifup' \
  -device "e1000,netdev=net0,mac=$macaddr" \
  -kernel buildos-image -initrd buildos-initrd \
  -append "buildos.smtp_relay=build2.org buildos.admin_email=admin@build.org"