Re: [pacman-dev] [PATCH] bacman - regenerate package from system

4 Jun 2008

Il Wednesday 04 June 2008 05:55:55 Allan McRae ha scritto:
...
Carlo Bersani wrote:
...
Hello,
I finally had a while to fix the permissions issue and to include
fakeroot support.
Great, tested this with mlocate and the permissions get setup nicely.  I
did notice one regression though.
We should add a warning here if fakeroot is missing so the user knows
the permissions might be messy.
The positioning of this block also needs to be considered, e.g.:
...
./bacman
Entering fakeroot environment
This program recreates a package using pacman's db and system files
Usage:   bacman <installed package name>
Example: bacman kernel26
Wops, that was stupid : )
I fixed that
...
...
+            if [ -e "/$i" ]; then
+                bsdtar -cnf - "/$i" 2> /dev/null | bsdtar -xpf -
+                ret=${PIPESTATUS[0]}
             else
                 echo "/$i" is missing: this might result in a broken
package fi
The ret catch from bsdtar is not working correctly.  E.g. making the
sudo package where the user does not have permission to read
/etc/sudoers no longer has that error caught.
And I even checked $PIPESTATUS behaviour before.
This looks like a problem with bsdtar which returns 0 even if the file is 
missing:

carlocci ~/.abs/tmp  $  bsdtar -cf foo.tar /etc/shadow && echo I\'m dumb!
bsdtar: Removing leading '/' from member names
bsdtar: /etc/shadow: could not open file: Permission denied
I'm dumb!
...
Instead of checking $PIPESTATUS, how about checking the actual file is
present:
if [ ! -e $work_dir/$i ]; then
  ret=1
fi
This is a nice workaround, as long as we can't trust bsdtar.

Here's the patch to the commit Allan made:

--- gitbacman	2008-06-03 19:02:14.000000000 +0200
+++ bacman	2008-06-04 18:43:19.000000000 +0200
@@ -43,12 +43,33 @@
 fi
 
 if [ "$1" = "--version" -o "$1" = "-v" ]; then
-    echo "$progname version $version"
+    echo "$progname version $progver"
     echo "Copyright (C) 2008 locci"
     exit 0
 fi
 
 #
+# Fakeroot support
+#
+if [ $EUID -gt 0 ]; then
+    if [ -f /usr/bin/fakeroot ]; then
+        echo "Entering fakeroot environment"
+        export INFAKEROOT="1"
+        /usr/bin/fakeroot -u -- $0 $1
+        exit $?
+    else
+        echo "You should install fakeroot or run $progname as root"
+        echo "Otherwise $progname won't be able to preserve the owner:group 
of the files"
+        exit 1
+    fi
+elif [ $EUID -eq 0 ]  && [ -z $INFAKEROOT ]; then
+    echo 
+    echo "CAUTION: you might be packaging security sensitive data!"
+    echo 
+fi
+
+#
 # Setting environmental variables
 #
 if [ ! -r /etc/pacman.conf ]; then
@@ -116,16 +137,21 @@
     case $current in
         %FILES%)
             ret=0
-            if [ -d "/$i" ]; then
-                mkdir "$i" || ret=$?
-            elif [ -f "/$i" ]; then
-                cp -dp "/$i" "$i" || ret=$?
+            if [ -e "/$i" ]; then
+                bsdtar -cnf - "/$i" 2> /dev/null | bsdtar -xpf -
             else
                 echo "/$i" is missing: this might result in a broken package
             fi
 
-            if [ $ret -ne 0 ]; then
-                echo Error: unable to create /$i
+            # Workaround to bsdtar not reporting a missing file as an error
+            if [ ! -e "$work_dir"/"$i" ]; then
+                echo 
+                echo "Error: unable to add /$i to the package"
+                echo "Check the file permissions, probably the file contains 
important data"
+                echo "If you can't read it as a user, you probably should not 
make a package"
+                echo "with it inside: it might result in a security hazard"
+                echo "Run $progname as root, if you know what you are doing"
+                echo 
                 exit 1
             fi
         ;;
@@ -152,6 +178,9 @@
 #
 echo Generating .PKGINFO metadata...
 echo "# Generated by $progname $progver"    > .PKGINFO
+if [ -n $INFAKEROOT ]; then
+    echo "# Using $(fakeroot -v)"    >> .PKGINFO
+fi
 echo "# $(LC_ALL=C date)"            >> .PKGINFO
 echo "#"                    >> .PKGINFO
 
@@ -208,7 +237,7 @@
         # files
         %BACKUP%)
             # strip the md5sum after the tab
-            echo "backup = ${i%%       *}"   >> .PKGINFO
+            echo "backup = ${i%%$'\t'*}"   >> .PKGINFO
         ;;
 
         # depends
@@ -228,6 +257,12 @@
 done
 
 #
+# Fixes owner:group and permissions for .PKGINFO, .CHANGELOG, .INSTALL
+#
+chown root:root $work_dir/{.PKGINFO,.CHANGELOG,.INSTALL} 2> /dev/null
+chmod 644 $work_dir/{.PKGINFO,.CHANGELOG,.INSTALL} 2> /dev/null
+
+#
 # Generate the package
 #
 echo Generating the package...
@@ -237,6 +272,7 @@
 if [ $ret -ne 0 ]; then
     echo Error: unable to write package to $pkg_dest
     echo Maybe the disk is full or you do not have write access
+    rm -rf $work_dir
     exit 1
 fi
 
@@ -247,3 +283,4 @@
 exit 0
 
 # vim: set ts=2 sw=2 noet:
+




Here's the whole script:
#!/bin/bash
#
#   bacman: recreate a package from a running system
#   This script rebuilds an already installed package using metadata
#   stored into the pacman database and system files
#
#   (c) 2008 - locci <carlocci_at_gmail_dot_com>
#
#   This program 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 2 of the License, or
#   (at your option) any later version.
#
#   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
#

readonly progname="bacman"
readonly progver="0.1.2"

#
# User Friendliness
#
function usage(){
    echo "This program recreates a package using pacman's db and system files"
    echo "Usage:   $progname <installed package name>"
    echo "Example: $progname kernel26"
}

if [ $# -ne 1 ] ; then
    usage
    exit 1
fi

if [ "$1" = "--help" -o "$1" = "-h" ] ; then
    usage
    exit 0
fi

if [ "$1" = "--version" -o "$1" = "-v" ]; then
    echo "$progname version $progver"
    echo "Copyright (C) 2008 locci"
    exit 0
fi

#
# Fakeroot support
#
if [ $EUID -gt 0 ]; then
    if [ -f /usr/bin/fakeroot ]; then
        echo "Entering fakeroot environment"
        export INFAKEROOT="1"
        /usr/bin/fakeroot -u -- $0 $1
        exit $?
    else
        echo "You should install fakeroot or run $progname as root"
        echo "Otherwise $progname won't be able to preserve the owner:group of 
the files"
        exit 1
    fi
elif [ $EUID -eq 0 ]  && [ -z $INFAKEROOT ]; then
    echo 
    echo "CAUTION: you might be packaging security sensitive data!"
    echo 
fi

#
# Setting environmental variables
#
if [ ! -r /etc/pacman.conf ]; then
    echo Error: unable to read /etc/pacman.conf
    exit 1
fi

eval $(awk '/DBPath/ {print $1$2$3}' /etc/pacman.conf)
pac_db="${DBPath:-/var/lib/pacman/}/local"

if [ ! -r /etc/makepkg.conf ]; then
    echo Error: unable to read /etc/makepkg.conf
    exit 1
fi

source "/etc/makepkg.conf"
if [ -r ~/.makepkg.conf ]; then
    source ~/.makepkg.conf
fi

pkg_arch=${CARCH:-'unknown'}
pkg_dest="${PKGDEST:-$PWD}"
pkg_pkger=${PACKAGER:-'Unknown Packager'}

pkg_name="$1"
pkg_dir="$(echo $pac_db/$pkg_name-[0-9]*)"
pkg_namver="${pkg_dir##*/}"

#
# Checks everything is in place
#
if [ ! -d "$pac_db" ] ; then
    echo Error: pacman database directory ${pac_db} not found
    exit 1
fi

if [ ! -d "$pkg_dir" ] ; then
    echo Error: package ${pkg_name} not found in pacman database
    exit 1
fi

#
# Begin
#
echo Package: ${pkg_namver}
work_dir=$(mktemp -d -p /tmp)
cd $work_dir || exit 1

#
# File copying
#
echo Copying package files...

cat "$pkg_dir"/files |
while read i; do
    if [ -z "$i" ] ; then
        continue
    fi

    if [[ "$i" =~ %[A-Z]*% ]] ; then
        current=$i
        continue
    fi

    case $current in
        %FILES%)
            ret=0
            if [ -e "/$i" ]; then
                bsdtar -cnf - "/$i" 2> /dev/null | bsdtar -xpf -
            else
                echo "/$i" is missing: this might result in a broken package
            fi

            # Workaround to bsdtar not reporting a missing file as an error
            if [ ! -e "$work_dir"/"$i" ]; then
                echo 
                echo "Error: unable to add /$i to the package"
                echo "Check the file permissions, probably the file contains 
important data"
                echo "If you can't read it as a user, you probably should not 
make a package"
                echo "with it inside: it might result in a security hazard"
                echo "Run $progname as root, if you know what you are doing"
                echo 
                exit 1
            fi
        ;;
    esac
done

ret=$?
if [ $ret -ne 0 ]; then
    rm -rf $work_dir
    exit 1
fi

pkg_size=$(du -sk | awk '{print $1 * 1024}')

if [ -f "$pkg_dir/install" ] ; then
    cp "$pkg_dir/install" "$work_dir/.INSTALL"
fi
if  [ -f $pkg_dir/changelog ] ; then
    cp "$pkg_dir/changelog" "$work_dir/.CHANGELOG"
fi

#
# .PKGINFO stuff
#
echo Generating .PKGINFO metadata...
echo "# Generated by $progname $progver"    > .PKGINFO
if [ -n $INFAKEROOT ]; then
    echo "# Using $(fakeroot -v)"    >> .PKGINFO
fi
echo "# $(LC_ALL=C date)"            >> .PKGINFO
echo "#"                    >> .PKGINFO

cat "$pkg_dir"/{desc,files,depends} |
while read i; do
    if [[ -z "$i" ]]; then
        continue;
    fi

    if [[ "$i" =~ %[A-Z]*% ]] ; then
        current=$i
        continue
    fi

    case "$current" in
        # desc
        %NAME%)
            echo "pkgname = $i"    >> .PKGINFO
        ;;
        %VERSION%)
            echo "pkgver = $i"    >> .PKGINFO
        ;;
        %DESC%)
            echo "pkgdesc = $i"    >> .PKGINFO
        ;;
        %URL%)
            echo "url = $i"    >> .PKGINFO
        ;;
        %LICENSE%)
            echo "license = $i"    >> .PKGINFO
        ;;
        %ARCH%)
            echo "arch = $i"    >> .PKGINFO
        ;;
        %BUILDDATE%)
            echo "builddate = $(date -u "+%s")"    >> .PKGINFO
        ;;
        %PACKAGER%)
            echo "packager = $pkg_pkger"        >> .PKGINFO
        ;;
        %SIZE%)
            echo "size = $pkg_size"        >> .PKGINFO
        ;;
        %GROUPS%)
            echo "group = $i"    >> .PKGINFO
        ;;
        %REPLACES%)
            echo "replaces = $i"    >> .PKGINFO
        ;;
        %FORCE%)
            echo "force = true" >> .PKGINFO
        ;;

        # files
        %BACKUP%)
            # strip the md5sum after the tab
            echo "backup = ${i%%$'\t'*}"   >> .PKGINFO
        ;;

        # depends
        %DEPENDS%)
            echo "depend = $i"   >> .PKGINFO
        ;;
        %OPTDEPENDS%)
            echo "optdepend = $i" >> .PKGINFO
        ;;
        %CONFLICTS%)
            echo "conflict = $i" >> .PKGINFO
        ;;
        %PROVIDES%)
            echo "provides = $i"  >> .PKGINFO
        ;;
    esac
done

#
# Fixes owner:group and permissions for .PKGINFO, .CHANGELOG, .INSTALL
#
chown root:root $work_dir/{.PKGINFO,.CHANGELOG,.INSTALL} 2> /dev/null
chmod 644 $work_dir/{.PKGINFO,.CHANGELOG,.INSTALL} 2> /dev/null

#
# Generate the package
#
echo Generating the package...

ret=0
bsdtar -czf "$pkg_dest/$pkg_namver-$pkg_arch.tar.gz" $(ls -A) || ret=$?
if [ $ret -ne 0 ]; then
    echo Error: unable to write package to $pkg_dest
    echo Maybe the disk is full or you do not have write access
    rm -rf $work_dir
    exit 1
fi

rm -rf $work_dir

echo Done

exit 0

# vim: set ts=2 sw=2 noet:

    