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Commit | Line | Data |
---|---|---|
1 | #!/bin/bash -e | |
2 | ||
3 | bootstrap() { | |
4 | [[ $(id -u) -eq 0 ]] || exec sudo env -uUNSHARE HOME="$HOME" "$0" "$@" | |
5 | ||
6 | if [[ -z ${UNSHARE} ]] ; then | |
7 | mount_args= | |
8 | if type -P unshare >&/dev/null ; then | |
9 | test_arg() { unshare "$@" -- true >&/dev/null && uargs+=( "$@" ) || :; } | |
10 | uargs=( -m ) | |
11 | test_arg -u | |
12 | test_arg -i | |
13 | test_arg -p -f --mount-proc | |
14 | test_arg --propagation=private | |
15 | UNSHARE=true exec unshare "${uargs[@]}" -- "$0" "$@" | |
16 | fi | |
17 | else | |
18 | mount_args='-n' | |
19 | fi | |
20 | unset UNSHARE | |
21 | } | |
22 | ||
23 | is_mounted() { | |
24 | local dst=$1 | |
25 | grep -sq "${dst}" /proc/mounts | |
26 | } | |
27 | ||
28 | maybe_mount() { | |
29 | local src=/$1 dst=${chroot}/${2:-$1} | |
30 | [[ -d ${src} ]] || return 0 | |
31 | if ! mkdir -p "${dst}" ; then | |
32 | [[ -w ${chroot} ]] && exit 1 || return 0 | |
33 | fi | |
34 | is_mounted "${dst}" || mount ${mount_args} --bind "${src}" "${dst}" | |
35 | } | |
36 | ||
37 | get_type() { | |
38 | case $(file "$1") in | |
39 | *x86-64*) echo x86_64;; | |
40 | *"Intel 80386"*) echo i386;; | |
41 | *32-bit*PowerPC*MSB*) echo ppc;; | |
42 | *64-bit*PowerPC*MSB*) echo ppc64;; | |
43 | *32-bit*PowerPC*LSB*) echo ppcle;; | |
44 | *64-bit*PowerPC*LSB*) echo ppc64le;; | |
45 | *32-bit*S/390*) echo s390;; | |
46 | *64-bit*S/390*) echo s390x;; | |
47 | *64-bit*MIPS*) echo mips64;; | |
48 | *32-bit*MIPS*N32*) echo mips64;; | |
49 | *32-bit*MIPS*) echo mips;; | |
50 | *32-bit*PA-RISC*) echo parisc;; | |
51 | *64-bit*PA-RISC*) echo parisc64;; | |
52 | *32-bit*SPARC*) echo sparc;; | |
53 | *64-bit*SPARC*) echo sparc64;; | |
54 | esac | |
55 | } | |
56 | ||
57 | init_chroot() { | |
58 | [[ -w . ]] || return 0 | |
59 | ||
60 | if [[ ! -L etc/mtab ]] ; then | |
61 | ln -sfT /proc/mounts etc/mtab | |
62 | fi | |
63 | local f dst | |
64 | local etc=( | |
65 | hosts | |
66 | locale.gen | |
67 | localtime | |
68 | resolv.conf | |
69 | ) | |
70 | local home=( | |
71 | .inputrc | |
72 | .gdbinit | |
73 | .gitconfig | |
74 | .nanorc | |
75 | ) | |
76 | for f in \ | |
77 | $(printf 'etc/%s ' "${etc[@]}") \ | |
78 | ; do | |
79 | if [[ -e /${f} ]] ; then | |
80 | cp "/${f}" "${f}" | |
81 | fi | |
82 | done | |
83 | for f in "${home[@]}" ; do | |
84 | df="root/${f}" | |
85 | f="${HOME}/${f}" | |
86 | if [[ -e ${f} ]] ; then | |
87 | cp "${f}" "${df}" | |
88 | fi | |
89 | done | |
90 | ||
91 | if [[ ! -d root/.git ]] ; then | |
92 | f="${HOME}/.profile.d/aliases.sh" | |
93 | if [[ -e ${f} ]] ; then | |
94 | cat "${f}" > root/.bash_profile | |
95 | fi | |
96 | fi | |
97 | } | |
98 | ||
99 | usage() { | |
100 | cat <<-EOF | |
101 | Usage: ${0##*/} [options] [program to run] | |
102 | ||
103 | Sets up common mount points and then chroots in and runs a program. | |
104 | If no program is specified, then launch a login shell. | |
105 | ||
106 | Options: | |
107 | -u Unmount all paths in the chroot | |
108 | -m <path> Add path to mount list | |
109 | -d <dir> Use <dir> as chroot (defaults to ${0%/*}) | |
110 | -h This help screen | |
111 | EOF | |
112 | exit | |
113 | } | |
114 | ||
115 | main() { | |
116 | bootstrap "$@" | |
117 | ||
118 | local mounts=( | |
119 | proc sys tmp dev dev/shm run | |
120 | usr/portage usr/portage/distfiles | |
121 | var/db/repos/gentoo var/cache/distfiles | |
122 | usr/local/src | |
123 | ) | |
124 | ||
125 | local chroot=${0%/*} | |
126 | case ${chroot} in | |
127 | .) chroot=${PWD} ;; | |
128 | ./*) chroot=${PWD}/${chroot#./} ;; | |
129 | esac | |
130 | ||
131 | local cmd | |
132 | while [[ -n $1 ]] ; do | |
133 | case $1 in | |
134 | -u) cmd='umount' ;; | |
135 | -m) mounts+=( "$2" ); shift ;; | |
136 | -d) chroot=$(realpath "$2"); shift ;; | |
137 | --help|-h) usage ;; | |
138 | -*) echo "${0##*/}: unknown option $1"; exit 1 ;; | |
139 | *) break ;; | |
140 | esac | |
141 | shift | |
142 | done | |
143 | cd "${chroot}" | |
144 | ||
145 | case ${cmd} in | |
146 | umount) exec "${0%/*}/umount-tree" -y "${chroot}" ;; | |
147 | esac | |
148 | ||
149 | local m | |
150 | for m in "${mounts[@]}" ; do | |
151 | maybe_mount "${m}" | |
152 | done | |
153 | # Handle special mounts that we don't want to just bind mount. | |
154 | if ! is_mounted "${chroot}/dev/pts" ; then | |
155 | # Option order matters: on older kernels that don't recognize newinstance, | |
156 | # parsing stops as soon as it hits that. | |
157 | mount -t devpts devpts "${chroot}/dev/pts" \ | |
158 | -o nosuid,noexec,mode=0620,gid=5,ptmxmode=0666,newinstance | |
159 | fi | |
160 | ||
161 | init_chroot | |
162 | ||
163 | local setarch | |
164 | if type -P setarch &>/dev/null ; then | |
165 | local bin_dst=$(get_type bin/bash) | |
166 | if [[ -n ${bin_dst} ]] ; then | |
167 | setarch="setarch ${bin_dst}" | |
168 | fi | |
169 | fi | |
170 | ||
171 | # Doubtful these settings we want to leak into the chroot. | |
172 | unset ROOT PORTAGE_CONFIGROOT LD_LIBRARY_PATH | |
173 | unset LS_COLORS # format changes over time | |
174 | [[ $# -eq 0 ]] && set -- env HOME=/root /bin/bash -l | |
175 | exec \ | |
176 | ${setarch} \ | |
177 | chroot "${chroot}" \ | |
178 | "$@" | |
179 | } | |
180 | ||
181 | main "$@" |