Synnefo » snf-image

#!/bin/bash

set -e

set -o pipefail

. @osdir@/common.sh

usage() {

    local rc="$1"

    cat <<EOF

Usage: $0 [options]

This script runs a debootstrap and creates a small Debian image populated with

the snf-image-helper package. This needs to be done before the first use of

ganeti's \`snf-image' guest OS type.

OPTIONS:

    -c CACHE_FILE

        Use this cache file, instead of the default

        [default: $HELPER_CACHE_FILE]

    -d DIRECTORY

        Use this directory to host the created files, instead of the default

        [default: $HELPER_DIR]

    -h  Print this message

    -p PACKAGE

        Install this deb package in the helper image, instead of the default

        [default: $HELPER_PKG]

    -y  Assume Yes to all queries and do not prompt

EOF

    exit "$rc"

}

while getopts "c:d:hp:y" opt; do

    case $opt in

        c) HELPER_CACHE_FILE="$OPTARG"

            ;;

        d) HELPER_DIR="$OPTARG"

            ;;

        h) usage 0

            ;;

        l) list_defaults; exit 0

            ;;

        p) HELPER_PKG="$OPTARG"

            ;;

        y) NO_PROMPT="yes"

            ;;

        ?) log_error "Use \`-h' for help"; exit 1

            ;;

    esac

done

echo

echo "This is the update helper image script for snf-image."

echo "If you don't know what to do, use \`-h'."

echo

if [ ! -d "$HELPER_DIR" -o ! -w "$HELPER_DIR" ]; then

    log_error "ERROR:"

    log_error "Helper directory \`$HELPER_DIR' does not exist or the script" \

    "has no write permission on it."

    exit 1

fi

if [ ! -r "$HELPER_PKG" ]; then

    log_error "ERROR:"

    log_error "Helper package \`$HELPER_PKG' does not exist or is not " \

    "readable by the script."

    exit 1

fi

cat >&1 <<EOF

This program will overwrite the following files if present:

  \`$HELPER_DIR/initrd'

  \`$HELPER_DIR/kernel'

  \`$HELPER_DIR/image'

EOF

while [[ 1 ]]; do

    echo -n "Do you want to continue [y/N]? "

    if [ "x$NO_PROMPT" = "xyes" ]; then

        echo "y";

        break;

    fi

    read answer

    [ "$(echo -n "$answer" | tr [A-Z] [a-z])" = "y" ] && break

    if [ -z "$answer" -o "$(echo -n "$answer" | tr [A-Z] [a-z])" = "n" ]; then

        log_error "Abort."

        exit 1

    fi

done

rm -f "$HELPER_DIR/initrd" "$HELPER_DIR/kernel" "$HELPER_DIR/image"

echo -n "Allocating space for helper disk image..."

helper_img=$(mktemp "$HELPER_DIR/image.XXXXXX")

dd if=/dev/zero of="$helper_img" bs=1k count=400000 &> /dev/null

echo "done"

echo "Creating partitions..."

blockdev=$("$LOSETUP" -sf $helper_img)

add_cleanup "$LOSETUP" -d "$blockdev"

sleep 1 # sometimes losetup returns and the device is still busy..

format_disk0 "$blockdev" "extdump"  2>&1 | sed -e 's/^/CFDISK: /g'

root_dev=$(map_disk0 "$blockdev")-1

add_cleanup unmap_disk0 "$blockdev"

echo Creating and configuring filesystem...

mkfs.ext3 "$root_dev" 2>&1 | sed -e 's/^/MKFS.EXT3: /g'

# The helper vm should never do filesystem checks...

tune2fs -i 0 -c 0 "$root_dev" 2>&1 | sed -e 's/^/TUNE2FS: /g'

target=$(mktemp -d)

add_cleanup rmdir "$target"

mount "$root_dev" "$target"

add_cleanup umount "$root_dev"

echo -n "Checking for cached root filesystem file \`$HELPER_CACHE_FILE'..." 

if [  -f "$HELPER_CACHE_FILE" ]; then

    echo "found"

    tar xf "$HELPER_CACHE_FILE" -C "$target"

else

    echo "not found"

    echo "Debootstraping to create a new root filesystem:"

    # Create a policy-rc.d file to deny init script execution

    mkdir -p "$target/usr/sbin"

    cat > "$target/usr/sbin/policy-rc.d" <<EOF

#!/bin/sh

exit 101

EOF

    chmod +x "$target/usr/sbin/policy-rc.d"

    debootstrap --arch amd64 --include "$HELPER_EXTRA_PKGS" \

        --variant=minbase stable "$target" "$HELPER_MIRROR" 2>&1 | \

        sed -e 's/^/DEBOOTSTRAP: /g'

    rm "$target/usr/sbin/policy-rc.d"

    # remove the downloaded debs, as they are no longer needed

    find "$target/var/cache/apt/archives" -type f -name '*.deb' -print0 | \

        xargs -r0 rm -f

    tmp_cache=$(mktemp "$HELPER_CACHE_FILE.XXXXXX")

    tar cf "$tmp_cache" --one-file-system -C "$target" . || \

        { rm "$tmp_cache"; false; }

    mv -f "$tmp_cache" "$HELPER_CACHE_FILE"

fi

echo -n "Configuring the helper image..."

echo snf-image-helper > "$target/etc/hostname"

cat > "$target/etc/fstab" <<EOF

# /etc/fstab: static file system information.

#

# <file system>   <mount point>   <type>  <options>       <dump>  <pass>

/dev/sda1         /               ext3    defaults        0       1

proc              /proc           proc    defaults        0       0

EOF

echo "done"

echo -n "Extracting kernel..."

if [ ! -L "$target/vmlinuz" -o ! -L "$target/vmlinuz" ]; then

    echo -e "\033[1;31mfailed\033[0m"

    log_error "vmlinuz or initrd.img link in root is missing."

    log_error "I don't know how to find a usable kernel/initrd pair."

    exit 1

fi

echo "done"

kernel=$(readlink -en "$target/vmlinuz")

initrd=$(readlink -en "$target/initrd.img")

echo "Moving $(basename "$kernel") and $(basename "$initrd") to \`$HELPER_DIR'"

mv "$kernel" "$initrd" "$HELPER_DIR"

kernel=$(basename "$kernel")

initrd=$(basename "$initrd")

(cd "$HELPER_DIR"; ln -fs "$kernel" kernel; ln -fs "$initrd" initrd)

rm "$target/vmlinuz" "$target/initrd.img"

echo "Installing snf-image-helper pkg in the new image..."

cp "$HELPER_PKG" "$target/tmp/"

pkg_name=$(basename "$HELPER_PKG")

add_cleanup rm "$target/tmp/$pkg_name"

chroot "$target" dpkg -i "/tmp/$pkg_name" 2>&1 | sed -e 's/^/DPKG: /g'

cat > "$target/etc/rc.local" <<EOF

#!/bin/sh -e

#

# rc.local

#

# This script is executed at the end of each multiuser runlevel.

# Make sure that the script will "exit 0" on success or any other

# value on error.

#

# In order to enable or disable this script just change the execution

# bits.

#

# By default this script does nothing.

if ! grep -q snf_image_activate_helper /proc/cmdline; then

    echo "WARNING: NOT calling snf-image-helper, add snf_image_activate_helper"

    echo "to the kernel command line if you want to do so."

else

    /usr/bin/snf-image-helper --force

fi

exit 0

EOF

chmod +x "$target/etc/rc.local"

echo "done"

cleanup

mv "$helper_img" "$HELPER_DIR/image"

trap - EXIT

echo "Files in \`$HELPER_DIR' were updated successfully"

exit 0

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