vagrant-rebox

#!/bin/sh

# vagrant-rebox - repackage a Vagrant box, to capture modifications

# Intended to make it possible to more quickly boot a vagrant VM that's
# been partially provisioned (or updated, or similar).  One can then
# change (or have the script change) the config.vm.box line to the newly
# captured box, and you'll now have a VM with a starting point of where
# your provisioned/updated box was, thus avoiding long delays in startup
# of a vagrant instance, at least of a particularly avoidable kind.

# Copyright 2014 by David Lindes.  All rights reserved.

# 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 3 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/>.

# This program is based loosely (and in part) on the instructions here,
# for which I am thankful:
# http://abhishek-tiwari.com/hacking/creating-a-new-vagrant-base-box-from-an-existing-vm

# default value for vmname:
vmname=default

usage() {
    cat <<EOF >&2
usage: $0 [-f] [-u] [-v <vmname>] boxname

Mandatory argument:

    boxname - specify the name for the new vagrant box

Options:

    -f           - force - clobber an existing vagrant box, if extant
    -u           - update - attempt to modify Vagrantfile to use the new box
    -v <vmname>  - specify the name (instead of "$vmname") of the vagrant VM
                   to use as a baseline.
EOF
}

run() {
    echo "-- Running: $*"
    "$@"
}

read_vbox_id() {
    box="$1"

    idfile=".vagrant/machines/$box/virtualbox/id"
    if [ ! -f "$idfile" ]
    then
	echo "Sorry, Couldn't find VirtualBox id for $box: $idfile doesn't exist" >&2
	exit 1
    fi

    cat "$idfile"
}

get_vbox_name() {
    # this actually seems easier, in shell, than showvminfo --machinereadable
    VBoxManage showvminfo "$1" | awk 'NR == 1 {print $2}'
}


force_arg=""
update=false

while getopts fuv: opt; do
    case "$opt" in
	f) force_arg="--force";;
	u) update=true;;
	v) vmname="$OPTARG";;
    esac
done
shift $((OPTIND - 1))

output="$1"; shift

# make sure we have an output file specified:
# TODO: some sort of sanity check on the name?
if [ -z "$output" ]; then
    usage
    exit 1
fi

# we don't know what to do with extra arguments; bail:
if [ ! -z "$*" ]; then
    echo "Extra arguments: $*" >&2
    usage
    exit 1
fi

tmpbox="/tmp/vrb-$output.box"

if [ -f "$tmpbox" ]; then
    echo "Sorry, $tmpbox already exists.  Please remove if you wish to overwrite."
    exit 1
fi

id=$(read_vbox_id $vmname)
if [ $? != 0 ]; then exit $?; fi

echo "Looking for information on box $vmname ($id)..."

# this isn't strictly necessary (using --base $id would work), but it
# makes it more user-friendly in its output:
vboxname=$(get_vbox_name "$id")
echo "- Found vbox name: $vboxname"

# exit on errors:
set -e

echo "- Packaging $vboxname as $tmpbox:"
run vagrant package --base "$vboxname" --output "$tmpbox"
echo "- Adding $tmpbox as $output:"
run vagrant box add $force_arg "$output" "$tmpbox"
rm -f "$tmpbox"

if $update; then
    echo "- Attempting to modify Vagrantfile to use $output:"
    echo "  Before: \c"
    perl -ne 'print if /^\s*\w+\.vm.box\s*=\s*["'\''].*["'\'']/' Vagrantfile
    # hmm, I think I won't do this under `run`... best with just
    # before/after, it seems to me:
    perl -pi.vagrant-rebox-backup -e 's/^(\s*\w+\.vm\.box\s*=\s*["'\'']).*["'\'']/$1'"$output"'"/' Vagrantfile
    echo "  After:  \c"
    perl -ne 'print if /^\s*\w+\.vm.box\s*=\s*["'\''].*["'\'']/' Vagrantfile
fi