pb-plugin: Update to chroot-style plugins

This change uses a chroot for all plugins, so that plugins have complete
flexibility with their libraries, dependencies and configuration.

We remove the 'install' action, as we simply run the plugin once.
Running involves extracting the archive, setting up a root filesystem,
and running a chroot.

To simplify plugin discovery behaviour, we standardise the plugin file
to be at pb-plugin.conf of attached devices, and read the metadatafile
straight out of the archive.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

diff --git a/utils/pb-plugin b/utils/pb-plugin
index e71e981a249cc1a74574600d5743be102fc1f595..4e4165257e21b6bfa11b215c1ace2fa79317d220 100755 (executable)
--- a/utils/pb-plugin
+++ b/utils/pb-plugin
@@ -2,8 +2,11 @@
 
 __dest=/
 __pb_mount_dir=/var/petitboot/mnt/dev/
 
 __dest=/
 __pb_mount_dir=/var/petitboot/mnt/dev/

-plugin_dev_meta=pb-plugin.conf
-plugin_installed_meta_dir=/etc/preboot-plugins/
+__plugin_basedir=/tmp/
+plugin_file=pb-plugin.cpio.gz
+plugin_meta=pb-plugin.conf
+plugin_meta_dir=etc/preboot-plugins/
+plugin_meta_path=$plugin_meta_dir$plugin_meta

 
 usage()
 {
 
 usage()
 {


@@ -11,9 +14,8 @@ usage()
 Usage: $0 <command>
 
 Where <command> is one of:
 Usage: $0 <command>
 
 Where <command> is one of:

-  install <FILE|URL>  - install plugin from FILE/URL
+  run <FILE|URL>      - run plugin from FILE/URL

   scan                - look for available plugins on attached devices
   scan                - look for available plugins on attached devices

-  list                - list currently-installed plugins

   create <DIR>        - create a new plugin archive from DIR
 EOF
 }
   create <DIR>        - create a new plugin archive from DIR
 EOF
 }


@@ -60,11 +62,41 @@ plugin_info()
        echo "  (version $PLUGIN_VERSION)"
 }
 
        echo "  (version $PLUGIN_VERSION)"
 }
 

-do_install()
+__run_init()

 {
 {

-       local url
+       local base dir
+
+       base=$1
+
+       for dir in etc dev sys proc
+       do
+               mkdir -p $base/$dir
+       done
+
+       cp /etc/resolv.conf $base/etc
+       mount -o bind /dev $base/dev
+       mount -o bind /sys $base/sys
+       mount -o bind /proc $base/proc
+}
+
+__run_cleanup()
+{
+       local base
+
+       base=$1
+
+       [ -e $base/dev/null ] && umount $base/dev
+       [ -e $base/sys/kernel ] && umount $base/sys
+       [ -e $base/proc/stat ] && umount $base/proc
+       rm -rf $base
+}
+
+do_run()
+{
+       local url executable

 
        url=$1
 
        url=$1

+       executable=$2

 
        if [ -z "$url" ]
        then
 
        if [ -z "$url" ]
        then


@@ -72,18 +104,6 @@ do_install()
                exit 1
        fi
 
                exit 1
        fi
 

-       if [ ! -d "$__dest" ]
-       then
-               echo "error: destination directory '$__dest' doesn't exist" >&2
-               exit 1
-       fi
-
-       if [ ! -w "$__dest" ]
-       then
-               echo "error: destination directory isn't writeable" >&2
-               exit 1
-       fi
-

        name=${url##*/}
 
        if is_url "$url"
        name=${url##*/}
 
        if is_url "$url"


@@ -109,7 +129,7 @@ do_install()
        echo
        sha256sum "$file" | cut -f1 -d' '
        echo
        echo
        sha256sum "$file" | cut -f1 -d' '
        echo

-       echo "Do you want to install into the pre-boot environment? (y/N)"
+       echo "Do you want to run this plugin? (y/N)"

        read resp
 
        case $resp in
        read resp
 
        case $resp in


@@ -121,33 +141,68 @@ do_install()
                ;;
        esac
 
                ;;
        esac
 

+       __dest=$(mktemp -d)

        gunzip -c "$file" | ( cd $__dest && cpio -i -d)
 
        if [ $? -ne 0 ]
        then
                echo "error: Failed to extract archive $url, exiting"
        gunzip -c "$file" | ( cd $__dest && cpio -i -d)
 
        if [ $? -ne 0 ]
        then
                echo "error: Failed to extract archive $url, exiting"

+               rm -rf $__dest

                exit 1
        fi
                exit 1
        fi

+
+       . $__dest/$plugin_meta_path
+
+       (
+               executable=${PLUGIN_EXECUTABLE:-$executable}
+
+               __run_init $__dest
+
+               printf "Entering plugin\n"
+               plugin_info
+
+               chroot $__dest $executable
+
+               printf "\nExiting plugin & cleaning up\n"
+               __run_cleanup $__dest
+       )
+

 }
 
 do_scan()
 {
 }
 
 do_scan()
 {

-       local found
+       local found dev plugin_path __meta_tmp

        found=0
        for mnt in $__pb_mount_dir/*
        do
                dev=$(basename $mnt)
        found=0
        for mnt in $__pb_mount_dir/*
        do
                dev=$(basename $mnt)

-               metafile="$mnt/$plugin_dev_meta"
-               [ -e "$metafile" ] || continue
+               plugin_path="$mnt/$plugin_file"
+
+               [ -e "$plugin_path" ] || continue
+
+               # extract plugin metadata to a temporary directory
+               __meta_tmp=$(mktemp -d)
+               [ -d $__meta_tmp ] || continue
+               gunzip -c "$plugin_path" |
+                       (cd $__meta_tmp &&
+                               cpio -i -d $plugin_meta_path 2>/dev/null)
+               if ! [ $? = 0 -a -e "$plugin_path" ]
+               then
+                       rm -rf $__meta_tmp
+                       continue
+               fi
+

                (
                (

-                       . $metafile
+                       . $__meta_tmp/$plugin_meta_path
+

                        printf "Plugin found on %s:\n" $dev
                        plugin_info
                        printf "\n"
                        printf "Plugin found on %s:\n" $dev
                        plugin_info
                        printf "\n"

-                       printf "To install this plugin, run:\n"
-                       printf "  $0 install $mnt/$PLUGIN_FILE\n"
+                       printf "To run this plugin:\n"
+                       printf "  $0 run $plugin_path\n"

                        printf "\n"
                )
                        printf "\n"
                )

+               rm -rf $__meta_tmp

                found=1
        done
 
                found=1
        done
 


@@ -157,36 +212,14 @@ do_scan()
        fi
 }
 
        fi
 }
 

-do_list()
-{
-       local found
-       found=0
-       for meta in $plugin_installed_meta_dir/*
-       do
-               [ -e "$meta" ] || continue
-               [ $found = 0 ] && printf "Installed plugins:\n"
-               found=1
-               (
-                       . $meta
-                       plugin_info
-                       echo
-               )
-       done
-
-       if [ "$found" = 0 ]
-       then
-               echo "No plugins installed"
-       fi
-}
-

 guided_meta()
 {
        local vendorname vendorshortname
        local pluginname pluginnhortname
 guided_meta()
 {
        local vendorname vendorshortname
        local pluginname pluginnhortname

-       local version date
-       local dir
+       local version date executable
+       local file

 
 

-       dir=$1
+       file=$1

 
 cat <<EOF
 
 
 cat <<EOF
 


@@ -224,22 +257,30 @@ Enter the plugin version. This should not contain spaces (eg 1.2):
 EOF
        read version
 
 EOF
        read version
 

+cat <<EOF
+
+Enter the full path (within the plugin root) to the plugin executable file.
+This will be the default action when the plugin is run. (eg /usr/bin/my-util)
+EOF
+       read executable
+

        date=$(date +%Y-%m-%d)
 
        date=$(date +%Y-%m-%d)
 

-       mkdir -p $dir
+       mkdir -p $(dirname $file)

 
 

-       cat <<EOF > $dir/$vendorshortname-$pluginshortname
+       cat <<EOF > $file

 PLUGIN_VENDOR='$vendorname'
 PLUGIN_NAME='$pluginname'
 PLUGIN_VERSION='$version'
 PLUGIN_DATE='$date'
 PLUGIN_VENDOR='$vendorname'
 PLUGIN_NAME='$pluginname'
 PLUGIN_VERSION='$version'
 PLUGIN_DATE='$date'

+PLUGIN_EXECUTABLE='$executable'

 EOF
 
 }
 
 do_create()
 {
 EOF
 
 }
 
 do_create()
 {

-       local src found meta_dir_abs meta_file
+       local src meta_dir_abs meta_file

        src=$1
 
        if [ -z "$src" ]
        src=$1
 
        if [ -z "$src" ]


@@ -255,16 +296,9 @@ do_create()
                exit 1
        fi
 
                exit 1
        fi
 

-       meta_dir_abs="$src/$plugin_installed_meta_dir"
-       found=0
-       for meta in $meta_dir_abs/*
-       do
-               [ -e "$meta" ] || continue
-               found=$(($found+1))
-               meta_file=$meta
-       done
+       meta_file=$src/$plugin_meta_path

 
 

-       if [ $found = 0 ]
+       if [ ! -e $meta_file ]

        then
                echo "No plugin metadata file found. " \
                        "Would you like to create one? (Y/n)"
        then
                echo "No plugin metadata file found. " \
                        "Would you like to create one? (Y/n)"


@@ -275,14 +309,7 @@ do_create()
                        exit 1
                        ;;
                esac
                        exit 1
                        ;;
                esac

-               guided_meta $meta_dir_abs || exit
-               meta_file=$meta_dir_abs/*
-       fi
-
-       if [ $found -gt 1 ]
-       then
-               echo "error: Multiple metadata files found in $meta_dir_abs" >&2
-               exit 1
+               guided_meta $meta_file || exit

        fi
 
        # Sanity check metadata file
        fi
 
        # Sanity check metadata file


@@ -308,18 +335,21 @@ do_create()
                        echo "error: no PLUGIN_DATE defined in metadata" &>2
                        exit 1
                fi
                        echo "error: no PLUGIN_DATE defined in metadata" &>2
                        exit 1
                fi

+               if [ ! -n "$PLUGIN_EXECUTABLE" ]
+               then
+                       echo "error: no PLUGIN_EXECUTABLE defined in metadata" \
+                               &>2
+                       exit 1
+               fi

 
        ) || exit 1
 
 
        ) || exit 1
 

-       outfile=pb-plugin.cpio.gz
+       outfile=$plugin_file

 
        (
                cd $src
                find -mindepth 1 | cpio -o -Hnewc -v
 
        (
                cd $src
                find -mindepth 1 | cpio -o -Hnewc -v

-       ) | gzip -c > pb-plugin.cpio.gz
-
-       cp $meta_file $plugin_dev_meta
-       echo "PLUGIN_FILE='$outfile'" >> $plugin_dev_meta
+       ) | gzip -c > $outfile

 
        echo
        echo "Plugin metadata:"
 
        echo
        echo "Plugin metadata:"


@@ -339,12 +369,9 @@ do_create()
 cat <<EOF
 Plugin created in:
   $outfile
 cat <<EOF
 Plugin created in:
   $outfile

-  
-Metadata in:
-  $plugin_dev_meta

 
 

-If you rename $outfile (or distribute it in a non-root directory), then
-also update the PLUGIN_FILE variable in $plugin_dev_meta.
+Ship this file in the top-level-directory of a USB device or CD to have it
+automatically discoverable by 'pb-plugin scan'.

 EOF
 }
 
 EOF
 }
 


@@ -388,12 +415,16 @@ test_scan()
 {
        __pb_mount_dir="$test_tmpdir/mnt"
        mnt_dir="$__pb_mount_dir/sda"
 {
        __pb_mount_dir="$test_tmpdir/mnt"
        mnt_dir="$__pb_mount_dir/sda"

-       mkdir -p $mnt_dir
+       mkdir -p $mnt_dir/$plugin_meta_dir

        (
                echo "PLUGIN_NAME=test"
                echo "PLUGIN_VERSION=1"
        (
                echo "PLUGIN_NAME=test"
                echo "PLUGIN_VERSION=1"

-               echo "PLUGIN_FILE=data/pb-plugin.cpio.gz"
-       ) > $mnt_dir/$plugin_dev_meta
+               echo "PLUGIN_EXECUTABLE=/bin/sh"
+       ) > $mnt_dir/$plugin_meta_path
+       (
+               cd $mnt_dir;
+               find -mindepth 1 | cpio -o -Hnewc 2>/dev/null
+       ) | gzip -c > $mnt_dir/$plugin_file

 
        do_scan | grep -q 'test 1'
        rc=$?
 
        do_scan | grep -q 'test 1'
        rc=$?


@@ -401,6 +432,8 @@ test_scan()
 
 test_empty_scan()
 {
 
 test_empty_scan()
 {

+       __pb_mount_dir="$test_tmpdir/mnt"
+       mkdir -p $__pb_mount_dir

        do_scan | grep -q "No plugins"
 }
 
        do_scan | grep -q "No plugins"
 }
 


@@ -410,10 +443,6 @@ test_setup()
 
        test_tmpdir="$tests_tmpdir/$n"
        mkdir "$test_tmpdir"
 
        test_tmpdir="$tests_tmpdir/$n"
        mkdir "$test_tmpdir"

-       __test_dest="$test_tmpdir/base"
-       mkdir "$__test_dest"
-       [ -d "$__test_dest" ] || exit 1
-       __dest=$__test_dest

 }
 
 test_teardown()
 }
 
 test_teardown()


@@ -479,18 +508,14 @@ do_tests()
 }
 
 case "$1" in
 }
 
 case "$1" in

-install)
+run)

        shift
        shift

-       do_install $@
+       do_run $@

        ;;
 scan)
        shift
        do_scan $@
        ;;
        ;;
 scan)
        shift
        do_scan $@
        ;;

-list)
-       shift
-       do_list $@
-       ;;

 create)
        shift
        do_create $@
 create)
        shift
        do_create $@