pmbootstrap-meow/pmb/chroot/init.py
Oliver Smith 68e1feef17 pmb: qemu-user-static from aport, not from Debian
Overview:
In order to execute foreign arch binaries on the host system, we are
using the Linux kernel's binfmt_misc feature in combination with
static builds of QEMU. Before this patch, the statically compiled
QEMU binaries were taken from Debian (mostly because I did not realize
that Alpine ships them as well). Now we can use the ones from the aport.

Benefits:
This allows us to easily update and patch the QEMU executables, we
don't need to be in sync with Debian's versions anymore.

Alpine's package is more modular, so we can save some download,
install, zap time, as well as disk space: setting up an armhf chroot
with pmbootstrap took ~102 MB before, now it's ~18 MB.

Detailed changes:
* Remove `cross/qemu-user-static-repack` aport
* Add `data/qemu-user-binfmt.txt` with the binfmt_misc flags for ELF
  binaries of various arches (extracted from Debian's packaging)
* When parsing that file, don't write verbose messages to
  `pmbootstrap log` anymore, only to the verbose log (can be enabled
  with `pmbootstrap -v`)
* Rename `pmb.parse.arch.alpine_to_debian()` to ...`alpine_to_qemu()`
* Rename `arch_debian` to `arch_qemu`
2018-08-10 15:11:21 +00:00

109 lines
4.1 KiB
Python

"""
Copyright 2018 Oliver Smith
This file is part of pmbootstrap.
pmbootstrap is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
pmbootstrap is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with pmbootstrap. If not, see <http://www.gnu.org/licenses/>.
"""
import logging
import os
import glob
import filecmp
import pmb.chroot
import pmb.chroot.apk_static
import pmb.config
import pmb.helpers.repo
import pmb.helpers.run
import pmb.parse.arch
def copy_resolv_conf(args, suffix="native"):
"""
Use pythons super fast file compare function (due to caching)
and copy the /etc/resolv.conf to the chroot, in case it is
different from the host.
If the file doesn't exist, create an empty file with 'touch'.
"""
host = "/etc/resolv.conf"
chroot = args.work + "/chroot_" + suffix + host
if os.path.exists(host):
if not os.path.exists(chroot) or not filecmp.cmp(host, chroot):
pmb.helpers.run.root(args, ["cp", host, chroot])
else:
pmb.helpers.run.root(args, ["touch", chroot])
def init(args, suffix="native"):
# When already initialized: just prepare the chroot
chroot = args.work + "/chroot_" + suffix
arch = pmb.parse.arch.from_chroot_suffix(args, suffix)
emulate = pmb.parse.arch.cpu_emulation_required(args, arch)
pmb.chroot.mount(args, suffix)
if os.path.islink(chroot + "/bin/sh"):
if emulate:
pmb.chroot.binfmt.register(args, arch)
copy_resolv_conf(args, suffix)
pmb.chroot.apk.update_repository_list(args, suffix)
return
# Require apk-tools-static
pmb.chroot.apk_static.init(args)
# Non-native chroot: set up QEMU with binfmt_misc
if emulate:
pmb.chroot.binfmt.register(args, arch)
logging.info("(" + suffix + ") install alpine-base")
# Initialize cache
apk_cache = args.work + "/cache_apk_" + arch
pmb.helpers.run.root(args, ["ln", "-s", "-f", "/var/cache/apk", chroot +
"/etc/apk/cache"])
# Initialize /etc/apk/keys/, resolv.conf, repositories
for key in glob.glob(pmb.config.apk_keys_path + "/*.pub"):
pmb.helpers.run.root(args, ["cp", key, args.work +
"/config_apk_keys/"])
copy_resolv_conf(args, suffix)
pmb.chroot.apk.update_repository_list(args, suffix)
# Non-native chroot: install qemu-user-binary
if emulate:
arch_qemu = pmb.parse.arch.alpine_to_qemu(arch)
pmb.helpers.run.root(args, ["mkdir", "-p", chroot + "/usr/bin"])
pmb.helpers.run.root(args, ["cp", args.work +
"/chroot_native/usr/bin/qemu-" + arch_qemu,
chroot + "/usr/bin/qemu-" + arch_qemu + "-static"])
# Install alpine-base
pmb.helpers.repo.update(args, arch)
pmb.chroot.apk_static.run(args, ["--no-progress", "--root", chroot,
"--cache-dir", apk_cache, "--initdb", "--arch", arch,
"add", "alpine-base"])
# Building chroots: create "pmos" user, add symlinks to /home/pmos
if not suffix.startswith("rootfs_"):
pmb.chroot.root(args, ["adduser", "-D", "pmos", "-u",
pmb.config.chroot_uid_user], suffix, auto_init=False)
# Create the links (with subfolders if necessary)
for target, link_name in pmb.config.chroot_home_symlinks.items():
link_dir = os.path.dirname(link_name)
if not os.path.exists(chroot + link_dir):
pmb.chroot.user(args, ["mkdir", "-p", link_dir], suffix)
pmb.chroot.user(args, ["ln", "-s", target, link_name], suffix)
pmb.chroot.root(args, ["chown", "pmos:pmos", target],
suffix)