selfstrap: internally manage /var/lib/dpkg/status

1 files changed, 91 insertions, 25 deletions

diff --git a/multistrap/selfstrap b/multistrap/selfstrap
index 88dc07e..c693a4e 100755
--- a/multistrap/selfstrap
+++ b/multistrap/selfstrap
@@ -43,6 +43,8 @@ apt_get()
     [ "$rootfs" ] || die 'no $rootfs'
     [ "$APT_CONFIG" ] || die 'no $APT_CONFIG'
 
+    visible_args="$*"
+
     set  --  -o  Apt::Install-Recommends=false                                "$@"
 
     # Set various paths to within the created system.
@@ -59,7 +61,7 @@ apt_get()
     # We must also set dpkg to use the created system.
     # Dpkg::options requires undocumented apt CLI magic.
     if [ "$DEBUG_DPKG" ]; then
-        [ "$DEBUG_DPKG" -gt 0 ] 2>/dev/null || DEBUG_DPKG=013
+        [ "$DEBUG_DPKG" -gt 0 ] 2>/dev/null || DEBUG_DPKG=10013
         set  --  -o  DPkg::options::arg0=--debug="${DEBUG_DPKG}"              "$@"
     fi
     # This is the important one:
@@ -75,9 +77,60 @@ apt_get()
     # Avoid deleting lists on the calling system.
     set  --  -o  APT::Get::List-Cleanup=false                                 "$@"
 
+    [ "$VERBOSE" ] && printf '+ apt-get %s\n' "$visible_args" >&2 || true
+
     apt-get "$@"
 }
 
+idem() { if [ ! -e "${!#}" ]; then "$@"; fi; }
+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
+    # src/core/cgroup.c in the systemd source tree.
+    idem_mknod -m 666 "$TARGET"/dev/null  c 1 3
+    idem_mknod -m 666 "$TARGET"/dev/zero  c 1 5
+    idem_mknod -m 666 "$TARGET"/dev/full  c 1 7
+    idem_mknod -m 666 "$TARGET"/dev/random        c 1 8
+    idem_mknod -m 666 "$TARGET"/dev/urandom       c 1 9
+    idem_mknod -m 666 "$TARGET"/dev/tty   c 5 0
+    idem mkdir "$TARGET"/dev/pts/
+    idem mkdir "$TARGET"/dev/shm/
+    # Inside a container, we might not be allowed to create /dev/ptmx.
+    # If not, do the next best thing.
+    if ! idem_mknod -m 666 "$TARGET"/dev/ptmx c 5 2; then
+        idem ln -s pts/ptmx "$TARGET"/dev/ptmx
+    fi
+    idem ln -s /proc/self/fd   "$TARGET"/dev/fd
+    idem ln -s /proc/self/fd/0 "$TARGET"/dev/stdin
+    idem ln -s /proc/self/fd/1 "$TARGET"/dev/stdout
+    idem ln -s /proc/self/fd/2 "$TARGET"/dev/stderr
+}
+
+mount_virtfs()
+{
+    local TARGET="$1"
+    [ "$TARGET" ] || die 'no $TARGET'
+    [ -d "$TARGET"/proc ] || mkdir "$TARGET"/proc
+    [ -d "$TARGET"/sys  ] || mkdir "$TARGET"/sys
+    mount -t proc proc "$TARGET"/proc
+    mount -t sysfs sysfs "$TARGET"/sys
+}
+
+umount_virtfs()
+{
+    local TARGET="$1" fail=
+    [ "$TARGET" ] || die 'no $TARGET'
+    umount "$TARGET"/proc || fail=y
+    umount "$TARGET"/sys || fail=y
+    [ ! "$fail" ]
+}
+
 write_lines_once()
 {
     local output="$1"
@@ -100,6 +153,7 @@ populate_rootfs()
     write_lines_once "$rootfs"/etc/apt/sources.list \
                      "deb $debian_mirror $release main contrib non-free" \
                      "deb http://security.debian.org $release/updates main contrib non-free"
+    install_devices
 }
 
 parse_apt_noact_line()
@@ -131,23 +185,33 @@ dpkg_extract_with_info()
     PKG=${PKG%%_*}
     PKG=$PKG$multiarch
 
-    command='
-[ "$TAR_FILENAME" = ./control ] && exit
-f=$TARGET/var/lib/dpkg/info/$PKG.${TAR_FILENAME#./}
-cat > "$f"
-chmod $TAR_MODE "$f"
-'
+    command=$(cat <<'EOF'
+if [ "$TAR_FILENAME" = ./control ]; then
+    (sed "/^Package:/a Status: install ok installed"; echo) >> "$TARGET"/var/lib/dpkg/status
+else
+    f=$TARGET/var/lib/dpkg/info/$PKG.${TAR_FILENAME#./}
+    cat > "$f"
+    chmod $TAR_MODE "$f"
+fi
+EOF
+)
     (export PKG TARGET; dpkg --ctrl-tarfile "$deb" | tar -x --to-command "$command")
     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 "$@" | while read line; do
+    apt_get -s -yqq install "$@" | dpkg_inst_from_apt
+}
+
+dpkg_inst_from_apt()
+{
+    while read line; do
         parse_apt_noact_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="$arch"
         is_multiarch_same "$package" && multiarch=":$arch" || multiarch=
         case "$action" in
@@ -174,7 +238,9 @@ apt_run_inst()
 apt_extract()
 {
     apt_get -d -yqq install "$@"
-    apt_get -s -yqq install "$@" | while read line; do
+    actions=$(mktemp) || die 'mktemp failed'
+    apt_get -s -yqq install "$@" | tee "$actions" | while read line; do
+
         parse_apt_noact_line "$line" || die "unexpected output from apt-get: $line"
 
         deb=/var/cache/apt/archives/${package}_${version//:/%3a}_${arch}.deb
@@ -194,18 +260,22 @@ apt_extract()
                     dpkg-deb --extract "$deb" "$rootfs"
                 fi
                 ;;
-            Conf)
-                ;;
+            Conf) ;;
             Remv) ;;
             *) die "impossible" ;;
         esac
     done
+    if [ "$EXTRACT_DPKG_INFO" ]; then
+        install_etc_passwd
+        dpkg_inst_from_apt < "$actions"
+    fi
+    rm "$actions"
 }
 
 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
+    [ -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()
@@ -273,8 +343,6 @@ packages=$(required_packages) && [ "$packages" ] || die 'failed to determine lis
 extra_packages='apt debian-archive-keyring locales'
 
 
-# Extract files from downloaded packages.
-#
 # Some files need to be present before 'apt-get install' can install anything.
 # In particular:
 #
@@ -282,20 +350,18 @@ extra_packages='apt debian-archive-keyring locales'
 #   2. /etc/passwd and /etc/group so that 'chown' works
 
 # Rather than fuss about (1), extract everything from all packages.
-apt_extract $packages
-# This handles (2).
-install_etc_passwd
 
+# Note: apt_extract() runs preinst and postinst scripts itself when
+# $EXTRACT_DPKG_INFO is true.
+apt_extract $packages
 
-# Finally we are ready to run apt-get install.
-export LC_ALL=C
-export DEBIAN_FRONTEND=noninteractive
 if [ "$SKIP_INSTALL" ]; then
     apt_extract $extra_packages
-    if [ "$RUN_INST_SCRIPTS" ]; then
-        apt_run_inst $packages $extra_packages
-    fi
 else
+    export LC_ALL=C
+    export DEBIAN_FRONTEND=noninteractive
+
+    install_etc_passwd # This handles (2).
     if [ "$FIX_BROKEN" ]; then
         dpkg --root="$rootfs" --configure -a
     fi