selfstrap: getopt-based CLI

1 files changed, 136 insertions, 121 deletions

diff --git a/src/selfstrap b/src/selfstrap
index 165a921..fc2ae5d 100755
--- a/src/selfstrap
+++ b/src/selfstrap
@@ -1,15 +1,50 @@
 #!/bin/bash
 debian_mirror=http://httpredir.debian.org/debian
-
-if [ $# = 1 ]; then
-    rootfs=$1
-else
-    echo "Usage: $0 <target directory>" >&2
-    exit 1
-fi
+EXTRA_PACKAGES='apt debian-archive-keyring locales'
 
 die() { printf 'Error: %s\n' "$*"; exit 1; }
 
+usage()
+{
+    echo "Usage: $0 -t <target directory> [options] [packages]" >&2
+    cat <<EOF
+  Options:
+    --target|-t        (Mandatory) Target directory
+    --help|-h
+    --verbose|-v
+    --unpack           Only unpack; do not configure
+    --chroot=<prog>    Use prog for chroot command
+    --packages=<file>  Text file contains names of packages to install
+    --real-apt         Use 'apt-get install' to install packages
+EOF
+    exit ${1:-1}
+}
+
+GETOPT=$(getopt -n "${0##*/}" -o t:hv --long help,target:,verbose,unpack,chroot:,packages:,real-apt -- "$@") || exit
+eval set -- "$GETOPT"
+while [ $# -gt 0 ]; do
+    case "$1" in
+        -t|--target) TARGET=$2; shift ;;
+        -h|--help) usage 0 ;;
+        -v|--verbose) VERBOSE=y ;;
+        --unpack) UNPACK_ONLY=y; die 'unimplemented' ;;
+        --packages) x=$(cat < "$2") || die "could not read file '$2'"
+                    EXTRA_PACKAGES="$EXTRA_PACKAGES $x"
+                    shift ;;
+        --chroot) CHROOT_PROG=$2; shift ;;
+        --real-apt) REAL_APT_INSTALL=y ;;
+        --) shift; break ;;
+        *) usage 1 ;;
+    esac
+    shift
+done
+
+[ "$TARGET" ] || usage
+
+! [ "$REAL_APT_INSTALL" -a "$UNPACK_ONLY" ] || die "option --real-apt is incompatible with option --unpack"
+
+EXTRA_PACKAGES="$EXTRA_PACKAGES $*"
+
 am_root() { [ "$(id -u)" = 0 ]; }
 
 current_debian_codename()
@@ -21,9 +56,9 @@ current_debian_codename()
 sanity_checks()
 {
     am_root || die 'you are not root'
-    rootfs=$(realpath "$rootfs") || die 'realpath failed'
-    [ "$rootfs" ] || die 'no $rootfs'
-    [ -d "$rootfs" ] || mkdir "$rootfs" || die 'could not mkdir($rootfs)'
+    TARGET=$(realpath "$TARGET") || die 'realpath failed'
+    [ "$TARGET" ] || die 'no $TARGET'
+    [ -d "$TARGET" ] || mkdir "$TARGET" || die 'could not mkdir($TARGET)'
 }
 
 generate_apt_config()
@@ -31,32 +66,37 @@ generate_apt_config()
     APT_CONFIG=$(mktemp) || exit
     chmod 644 "$APT_CONFIG"
     cat > "$APT_CONFIG" <<EOF
-Dir::Etc "${rootfs}/etc/apt/";
-Dir::Etc::Parts "${rootfs}/etc/apt/apt.conf.d/";
-Dir::Etc::PreferencesParts "${rootfs}/etc/apt/preferences.d/";
+Dir::Etc "${TARGET}/etc/apt/";
+Dir::Etc::Parts "${TARGET}/etc/apt/apt.conf.d/";
+Dir::Etc::PreferencesParts "${TARGET}/etc/apt/preferences.d/";
 EOF
     export APT_CONFIG
 }
 
-apt_get()
+apt_()
 {
-    [ "$rootfs" ] || die 'no $rootfs'
+    local apt_cmd="$1"
+    shift
+
+    [ "$TARGET" ] || die 'no $TARGET'
     [ "$APT_CONFIG" ] || die 'no $APT_CONFIG'
 
-    visible_args="$*"
+    if [ "$VERBOSE" ]; then
+        printf "+ apt-${apt_cmd} %s\n" "$*" >&2
+    fi
 
     set  --  -o  Apt::Install-Recommends=false                                "$@"
 
     # Set various paths to within the created system.
-    set  --  -o  Apt::Architecture="$rootfs_arch"                             "$@"
-    set  --  -o  Apt::Default-Release="$release"                              "$@"
-    set  --  -o  Dir="$rootfs"                                                "$@"
-    set  --  -o  Dir::Cache="$rootfs"/var/cache/apt/                          "$@"
-    set  --  -o  Dir::Etc::Parts="$rootfs"/etc/apt/apt.conf.d/                "$@"
-    set  --  -o  Dir::Etc::PreferencesParts="$rootfs"/etc/apt/preferences.d/  "$@"
-    set  --  -o  Dir::Etc="$rootfs"/etc/apt/                                  "$@"
-    set  --  -o  Dir::State="$rootfs"/var/lib/apt/                            "$@"
-    set  --  -o  Dir::State::Status="$rootfs"/var/lib/dpkg/status             "$@"
+    set  --  -o  Apt::Architecture="$target_arch"                             "$@"
+    set  --  -o  Apt::Default-Release="$target_release"                       "$@"
+    set  --  -o  Dir="$TARGET"                                                "$@"
+    set  --  -o  Dir::Cache="$TARGET"/var/cache/apt/                          "$@"
+    set  --  -o  Dir::Etc::Parts="$TARGET"/etc/apt/apt.conf.d/                "$@"
+    set  --  -o  Dir::Etc::PreferencesParts="$TARGET"/etc/apt/preferences.d/  "$@"
+    set  --  -o  Dir::Etc="$TARGET"/etc/apt/                                  "$@"
+    set  --  -o  Dir::State="$TARGET"/var/lib/apt/                            "$@"
+    set  --  -o  Dir::State::Status="$TARGET"/var/lib/dpkg/status             "$@"
 
     # We must also set dpkg to use the created system.
     # Dpkg::options requires undocumented apt CLI magic.
@@ -65,7 +105,7 @@ apt_get()
         set  --  -o  DPkg::options::arg0=--debug="${DEBUG_DPKG}"              "$@"
     fi
     # This is the important one:
-    set  --  -o  DPkg::options::arg1=--root="$rootfs"                         "$@"
+    set  --  -o  DPkg::options::arg1=--root="$TARGET"                         "$@"
     set  --  -o  DPkg::options::arg2=--force-unsafe-io                        "$@"
 
     # Use the calling system for these.  This is an optimization.
@@ -77,10 +117,10 @@ apt_get()
     # Avoid deleting lists on the calling system.
     set  --  -o  APT::Get::List-Cleanup=false                                 "$@"
 
-    [ "$VERBOSE" ] && printf '+ apt-get %s\n' "$visible_args" >&2 || true
-
-    apt-get "$@"
+    apt-"${apt_cmd}" "$@"
 }
+apt_get() { apt_ get "$@"; }
+apt_cache() { apt_ cache "$@"; }
 
 idem() { if [ ! -e "${!#}" ]; then "$@"; fi; }
 idem_mknod() { if [ ! -e "$3" ]; then mknod "$@"; fi; }
@@ -88,7 +128,6 @@ idem_mknod() { if [ ! -e "$3" ]; then mknod "$@"; fi; }
 # This function is copied (with modifications) from debootstrap.
 install_devices()
 {
-    local TARGET="$rootfs"
     [ "$TARGET" -a -d "$TARGET" ] || die 'no $TARGET'
     idem mkdir "$TARGET"/dev
     # The list of devices that can be created in a container comes from
@@ -114,7 +153,6 @@ install_devices()
 
 mount_virtfs()
 {
-    local TARGET="$1"
     [ "$TARGET" ] || die 'no $TARGET'
     [ -d "$TARGET"/proc ] || mkdir "$TARGET"/proc
     [ -d "$TARGET"/sys  ] || mkdir "$TARGET"/sys
@@ -124,7 +162,6 @@ mount_virtfs()
 
 umount_virtfs()
 {
-    local TARGET="$1" fail=
     [ "$TARGET" ] || die 'no $TARGET'
     umount "$TARGET"/proc || fail=y
     umount "$TARGET"/sys || fail=y
@@ -140,23 +177,23 @@ write_lines_once()
 
 populate_rootfs()
 {
-    [ "$rootfs" ] || die 'no $rootfs'
+    [ "$TARGET" ] || die 'no $TARGET'
     set -B
     mkdir -p \
-          "$rootfs"/etc/apt/{preferences.d,apt.conf.d,trusted.gpg.d,sources.list.d} \
-          "$rootfs"/var/{lib/{apt/lists/partial,dpkg/{info,parts,triggers,alternatives,updates}},cache/apt} \
-          "$rootfs"/var/log/apt
+          "$TARGET"/etc/apt/{preferences.d,apt.conf.d,trusted.gpg.d,sources.list.d} \
+          "$TARGET"/var/{lib/{apt/lists/partial,dpkg/{info,parts,triggers,alternatives,updates}},cache/apt} \
+          "$TARGET"/var/log/apt
 
-    touch "$rootfs"/var/lib/dpkg/status
+    touch "$TARGET"/var/lib/dpkg/status
 
-    write_lines_once "$rootfs"/var/lib/dpkg/arch "$rootfs_arch"
-    write_lines_once "$rootfs"/etc/apt/sources.list \
-                     "deb $debian_mirror $release main contrib non-free" \
-                     "deb http://security.debian.org $release/updates main contrib non-free"
+    write_lines_once "$TARGET"/var/lib/dpkg/arch "$target_arch"
+    write_lines_once "$TARGET"/etc/apt/sources.list \
+                     "deb $debian_mirror $target_release main contrib non-free" \
+                     "deb http://security.debian.org $target_release/updates main contrib non-free"
     install_devices
 }
 
-parse_apt_noact_line()
+parse_apt_simul_line()
 {
     set -- $*
     action=$1
@@ -178,16 +215,20 @@ parse_apt_noact_line()
     return 1
 }
 
-dpkg_extract_with_info()
+dpkg_unpack()
 {
-    local deb="$1" TARGET="$2" multiarch="$3" command PKG
+    [ "$TARGET" -a -d "$TARGET" ] || die 'no $TARGET'
+    local deb="$1" multiarch="$2" SET_STATUS="$3" command PKG
     PKG=${deb##*/}
     PKG=${PKG%%_*}
     PKG=$PKG$multiarch
 
+    # TODO: always set status=installed if there is no preinst or postinst script
+
     command=$(cat <<'EOF'
-if [ "$TAR_FILENAME" = ./control ]; then
-    (sed "/^Package:/a Status: install ok installed"; echo) >> "$TARGET"/var/lib/dpkg/status
+set -e
+if [ "$SET_STATUS" -a "$TAR_FILENAME" = ./control ]; then
+    (sed "/^Package:/a Status: install ok $SET_STATUS"; echo) >> "$TARGET"/var/lib/dpkg/status
 else
     f=$TARGET/var/lib/dpkg/info/$PKG.${TAR_FILENAME#./}
     cat > "$f"
@@ -195,21 +236,16 @@ else
 fi
 EOF
 )
-    (export PKG TARGET; dpkg --ctrl-tarfile "$deb" | tar -x --to-command "$command")
+    (export PKG TARGET SET_STATUS; dpkg --ctrl-tarfile "$deb" | tar -x --to-command "$command") || die 'tar'
     dpkg --fsys-tarfile "$deb" |
         (cd "$TARGET" && tar -xv) |
         sed 's?^\.??; s?^/$?/.?; s?/$??' > "$TARGET/var/lib/dpkg/info/$PKG.list"
 }
 
-apt_run_inst()
-{
-    apt_get -s -yqq install "$@" | dpkg_inst_from_apt
-}
-
-dpkg_inst_from_apt()
+dpkg_configure_from_apt_actions()
 {
     while read line; do
-        parse_apt_noact_line "$line" || die "unexpected output from apt-get: $line"
+        parse_apt_simul_line "$line" || die "unexpected output from apt-get: $line"
         export LC_ALL=C
         export DEBIAN_FRONTEND=noninteractive
         export DPKG_MAINTSCRIPT_PACKAGE="$package" DPKG_MAINTSCRIPT_ARCH="$arch"
@@ -218,19 +254,19 @@ dpkg_inst_from_apt()
             Inst)
                 export DPKG_MAINTSCRIPT_NAME=preinst
                 preinst=/var/lib/dpkg/info/${package}${multiarch}.preinst
-                if [ -x "$rootfs"/"$preinst" ]; then
-                    (set -x; chroot "$rootfs" "$preinst" install)
+                if [ -x "$TARGET"/"$preinst" ]; then
+                    ${CHROOT_PROG:-chroot} "$TARGET" "$preinst" install
                 fi
                 ;;
             Conf)
                 export DPKG_MAINTSCRIPT_NAME=postinst
                 postinst=/var/lib/dpkg/info/${package}${multiarch}.postinst
-                if [ -x "$rootfs"/"$postinst" ]; then
-                    (set -x; chroot "$rootfs" "$postinst" configure)
+                if [ -x "$TARGET"/"$postinst" ]; then
+                    ${CHROOT_PROG:-chroot} "$TARGET" "$postinst" configure
                 fi
                 ;;
             Remv) ;;
-            *) die "impossible" ;;
+            *) die "unexpected output from 'apt-get -s'" ;;
         esac
     done
 }
@@ -239,21 +275,23 @@ apt_extract()
 {
     apt_get -d -yqq install "$@"
     actions=$(mktemp) || die 'mktemp failed'
-    apt_get -s -yqq install "$@" | tee "$actions" | dpkg_extract_from_apt
+    apt_get -s -yqq install "$@" > "$actions" || die 'apt-get failed'
 
-    if [ "$EXTRACT_DPKG_INFO" ]; then
+    dpkg_unpack_from_apt_actions < "$actions" || die 'dpkg unpack (using internal dpkg) failed'
+
+    if [ ! "$UNPACK_ONLY" ]; then
         install_etc_passwd
-        dpkg_inst_from_apt < "$actions"
+        dpkg_configure_from_apt_actions < "$actions" || die 'dpkg configure (using internal dpkg) failed'
     fi
 
     rm "$actions"
 }
 
-dpkg_extract_from_apt()
+dpkg_unpack_from_apt_actions()
 {
     while read line; do
 
-        parse_apt_noact_line "$line" || die "unexpected output from apt-get: $line"
+        parse_apt_simul_line "$line" || die "unexpected output from apt-get: $line"
 
         deb=/var/cache/apt/archives/${package}_${version//:/%3a}_${arch}.deb
         [ -f "$deb" ] || {
@@ -263,43 +301,31 @@ dpkg_extract_from_apt()
         }
         case "$action" in
             Inst)
-                printf 'Extracting %s\n' "${deb##*/}" >&2
+                printf 'Unpacking %s\n' "${deb##*/}" >&2
+
+                is_multiarch_same "$package" && multiarch=":$arch" || multiarch=
+                [ "$UNPACK_ONLY" ] && set_status=unpacked || set_status=installed
+                dpkg_unpack "$deb" "$multiarch" "$set_status" || die "dpkg_unpack"
 
-                if [ "$EXTRACT_DPKG_INFO" ]; then
-                    is_multiarch_same "$package" && multiarch=":$arch" || multiarch=
-                    dpkg_extract_with_info "$deb" "$rootfs" "$multiarch"
-                else
-                    dpkg-deb --extract "$deb" "$rootfs"
-                fi
                 ;;
             Conf) ;;
             Remv) ;;
-            *) die "impossible" ;;
+            *) die "unexpected output from 'apt-get -s'" ;;
         esac
     done
 }
 
 install_etc_passwd()
 {
-    [ -e "$rootfs"/etc/passwd ] || cp "$rootfs"/usr/share/base-passwd/passwd.master "$rootfs"/etc/passwd
-    [ -e "$rootfs"/etc/group  ] || cp "$rootfs"/usr/share/base-passwd/group.master  "$rootfs"/etc/group
-}
-
-main_packages_file()
-{
-    local uri_part="${debian_mirror#*/}"
-    while [ "${uri_part:0:1}" = / ]; do
-        uri_part=${uri_part#?}
-    done
-    uri_part=${uri_part//\//_}
-    printf '/var/lib/apt/lists/%s_dists_%s_main_binary-%s_Packages\n' "$uri_part" "$release" "$rootfs_arch"
+    [ -e "$TARGET"/etc/passwd ] || cp "$TARGET"/usr/share/base-passwd/passwd.master "$TARGET"/etc/passwd
+    [ -e "$TARGET"/etc/group  ] || cp "$TARGET"/usr/share/base-passwd/group.master  "$TARGET"/etc/group
 }
 
 required_packages()
 {
-    perl -00 -ne \
-         '/^Priority: required/m || next; /^Package: (.*)$/m && print "$1\n"' \
-         "$(main_packages_file)" | sort -u
+    apt_cache dumpavail |
+        perl -00 -ne '/^Priority: required/m || next; /^Package: (.*)$/m && print "$1\n"' |
+        sort -u
 }
 
 declare -A is_multiarch_same
@@ -316,9 +342,9 @@ multicheck()
 
 multiarch_same_packages()
 {
-    perl -00 -ne \
-         '/^Multi-Arch: same/mi || next; /^Package: (.*)$/m && print "$1\n"' \
-         "$(main_packages_file)" | sort -u
+    apt_cache dumpavail |
+        perl -00 -ne '/^Multi-Arch: same/mi || next; /^Package: (.*)$/m && print "$1\n"' |
+        sort -u
 }
 
 is_multiarch_same()
@@ -329,48 +355,37 @@ is_multiarch_same()
 
 set -e
 
-rootfs_arch=$(dpkg-architecture -q DEB_HOST_ARCH) || die 'dpkg-architecture failed'
-release=$(current_debian_codename) && [ "$release" ] || die 'could not determine Debian release name'
-
-if [ "$FAST_MODE" ]; then
-    SKIP_INSTALL=y
-    EXTRACT_DPKG_INFO=y
-    RUN_INST_SCRIPTS=y
-fi
+target_arch=$(dpkg-architecture -q DEB_HOST_ARCH) || die 'dpkg-architecture failed'
+target_release=$(current_debian_codename) && [ "$target_release" ] || die 'could not determine Debian release name'
 
 # Set things up so apt-get update works.
 sanity_checks
 generate_apt_config
 populate_rootfs
-
-
-# Initial apt-get update will determine what we shall install.
 [ "$SKIP_UPDATE" ] || apt_get update
+
 packages=$(required_packages) && [ "$packages" ] || die 'failed to determine list of required packages'
-extra_packages='apt debian-archive-keyring locales'
 
+export LC_ALL=C
+export DEBIAN_FRONTEND=noninteractive
 
-# Some files need to be present before 'apt-get install' can install anything.
-# In particular:
-#
-#   1. binaries used by dpkg 'inst' scripts.
-#   2. /etc/passwd and /etc/group so that 'chown' works
+if [ "$REAL_APT_INSTALL" ]; then
+    # Some files need to be present before 'apt-get install' can install anything.
+    # In particular:
+    #
+    #   1. binaries used by dpkg 'inst' scripts.
+    #   2. /etc/passwd and /etc/group so that 'chown' works
 
-# Rather than fuss about (1), extract everything from all packages.
+    # Unpack required packages.  Handles (1)
+    UNPACK_ONLY=y apt_extract $packages
 
-# Note: apt_extract() runs preinst and postinst scripts itself when
-# $EXTRACT_DPKG_INFO is true.
-apt_extract $packages
+    # This handles (2).
+    # An alternative (used by debootstrap) is to configure base-passwd
+    install_etc_passwd
 
-if [ "$SKIP_INSTALL" ]; then
-    apt_extract $extra_packages
+    dpkg --root="$TARGET" --configure -a
+    apt_get install -y $EXTRA_PACKAGES
 else
-    export LC_ALL=C
-    export DEBIAN_FRONTEND=noninteractive
-
-    install_etc_passwd # This handles (2).
-    if [ "$FIX_BROKEN" ]; then
-        dpkg --root="$rootfs" --configure -a
-    fi
-    apt_get install -y $packages $extra_packages
+    apt_extract $packages
+    apt_extract $EXTRA_PACKAGES
 fi