.TH alpine-chroot-install 8 "2022-07-22" "Alpine Linux"
.SH NAME
alpine-chroot-install \- bootstrap an Alpine Linux chroot
.SH SYNOPSIS
.B alpine-chroot-install
.B -d
.I /directory
.RI [ options ]
.SH DESCRIPTION
This script installs Alpine Linux into a chroot and optionally sets up
qemu-user and binfmt to emulate different architecture (e.g. armhf).
.SH OPTIONS AND ENVIRONMENT VARIABLES
.TP
.B -a ARCH
CPU architecture for the chroot. If not set, then it's
the same as the host's architecture. If it's different
from the host's architecture, then it will be emulated
using qemu-user. Options: x86_64, x86, aarch64, armhf,
armv7, ppc64le, riscv64, s390x.
.TP
.B -b ALPINE_BRANCH
Alpine branch to install (default is latest-stable).
.TP
.B -d CHROOT_DIR
Absolute path to the directory where Alpine chroot
should be installed; Debian's version of this script
requires giving this explicitly -- such as
.B -d
.I /alpine
.TP
.B -i BIND_DIR
Absolute path to the directory on the host system that
should be mounted on the same path inside the chroot
(default is PWD, if it's under /home, or none).
.TP
.B -k CHROOT_KEEP_VARS
Names of the environment variables to pass from the
host environment into chroot by the enter-chroot
script. Name may be an extended regular expression.
Default: ARCH CI QEMU_EMULATOR TRAVIS_.*.
.TP
.B -m ALPINE_MIRROR
URI of the Aports mirror to fetch packages from
(default is http://dl-cdn.alpinelinux.org/alpine).
.TP
.B -p ALPINE_PACKAGES
Alpine packages to install into the chroot (default is
build-base ca-certificates ssl_client).
.TP
.B -r EXTRA_REPOS
Alpine repositories to be added to
/etc/apk/repositories (main and community from
$ALPINE_MIRROR are always added).
.TP
.B -t TEMP_DIR
Absolute path to the directory where to store temporary
files (defaults to `mktemp -d`).
.TP
.B -h
Show this help message and exit.
.TP
.B -v
Print version and exit.
.TP
.B APK_TOOLS_URI
URL of apk.static to download. Default is x86_64
binary from
https://gitlab.alpinelinux.org/alpine/apk-tools/-/packages.
.TP
.B APK_TOOLS_SHA256
SHA-256 checksum of $APK_TOOLS_URI.
.PP
Each option can be also provided by environment variable. If both option and
variable is specified and the option accepts only one argument, then the
option takes precedence.

.SH AFTER INSTALL
This tool also creates script "enter-chroot" inside the chroot directory, that may
be used to enter the chroot environment. That script do the following:
.IP
1. saves environment variables specified by $CHROOT_KEEP_VARS and PWD,

2. chroots into $CHROOT_DIR,

3. starts clean environment using "env -i",

4. switches user and simulates full login using "su -l",

5. loads saved environment variables and changes directory to saved PWD,

6. executes specified command or "sh" if not provided.
.PP
Example:
.EX
sudo alpine-chroot-install -d /alpine -p build-base -p cmake
/alpine/enter-chroot -u $USER ./build
.EE