Shell script to demonstrate docker migration with CRIU

docker-migrate.sh

#!/bin/bash -e

function run-vg-cmd() {
    pushd $1
    eval $2
    popd
}

function usage() {
    echo "Usage: $0 container from-vagrant-dir to-vagrant-dir"
}

if [ $# -eq 0 ]
then
    echo "$0: Migrating a Docker container from one vagrant host to another"
    echo ""
    usage
    exit 1
fi

workdir="/tmp/docker-migration"
container=$1
vagrant_from=$2
vagrant_to=$3

if test "${container}" = ""; then
    echo 'container is required'
    echo ""
    usage
    exit 1
fi

if test "${vagrant_from}" = ""; then
    echo 'vagrant-from-dir is required'
    echo ""
    usage
    exit 1
fi

if test "${vagrant_to}" = ""; then
    echo 'vagrant-to-dir is required'
    echo ""
    usage
    exit 1
fi

# Cleanup first
rm -rf $workdir && mkdir -p $workdir && cd $workdir
run-vg-cmd $vagrant_from "vagrant ssh -- sudo rm -rf /tmp/$container"
run-vg-cmd $vagrant_to   "vagrant ssh -- sudo rm -rf /tmp/$container"

# Dump ssh config for scp
run-vg-cmd $vagrant_from "vagrant ssh-config > ssh.config"
run-vg-cmd $vagrant_to   "vagrant ssh-config > ssh.config"

# Checkpoint a container
run-vg-cmd $vagrant_from "vagrant ssh -- docker checkpoint --image-dir=/tmp/$container $container"

# Copy container dump
run-vg-cmd $vagrant_from "scp -F ssh.config -r vagrant@default:/tmp/$container $workdir/$container"
run-vg-cmd $vagrant_to   "scp -F ssh.config -r $workdir/$container vagrant@default:/tmp/$container"

# Restore container from dump
run-vg-cmd $vagrant_to "vagrant ssh -- 'docker rm -f $container >/dev/null 2>&1; docker restore --force=true --image-dir=/tmp/$container \`docker create --name=$container busybox\`'"