Checkpoint and Restore Containers

Compile docker with checkpoint and restore enabled (ubuntu)

In order to compile docker its recommended you have at least 2 GB RAM. Even with that it fails sometimes so its better to go for 4GB instead.

make sure git and make is installed
```
sudo apt-get install make git-core -y
```

install a new kernel (at least 4.2)

sudo apt-get install linux-generic-lts-xenial

reboot machine to have the new kernel active
```
sudo reboot
```

compile criu which is needed in order to run docker checkpoint

sudo apt-get install libprotobuf-dev libprotobuf-c0-dev protobuf-c-compiler protobuf-compiler python-protobuf libnl-3-dev libcap-dev -y
wget https://download.openvz.org/criu/criu-2.4.tar.bz2 -O - | tar -xj
cd criu-2.4
make
make install-lib
make install-criu

check if every requirement is fulfilled to run criu
```
sudo criu check
```

compile experimental docker ( we need docker to compile docker)

cd ~
wget -qO- https://get.docker.com/ | sh
sudo usermod -aG docker $(whoami)

At this point we have to logoff and login again to have a docker daemon. After relog continue with compile step

git clone https://github.com/boucher/docker
cd docker
git checkout docker-checkpoint-restore
make #that will take some time - drink a coffee
DOCKER_EXPERIMENTAL=1 make binary

We now have a compiled docker. Lets move the binaries. Make sure to replace <version> with the version installed

sudo service docker stop
sudo cp $(which docker) $(which docker)_ ; sudo cp ./bundles/latest/binary-client/docker-<version>-dev $(which docker)
sudo cp $(which docker-containerd) $(which docker-containerd)_ ; sudo cp ./bundles/latest/binary-daemon/docker-containerd $(which docker-containerd)
sudo cp $(which docker-containerd-ctr) $(which docker-containerd-ctr)_ ; sudo cp ./bundles/latest/binary-daemon/docker-containerd-ctr $(which docker-containerd-ctr)
sudo cp $(which docker-containerd-shim) $(which docker-containerd-shim)_ ; sudo cp ./bundles/latest/binary-daemon/docker-containerd-shim $(which docker-containerd-shim)
sudo cp $(which dockerd) $(which dockerd)_ ; sudo cp ./bundles/latest/binary-daemon/dockerd $(which dockerd)
sudo cp $(which docker-runc) $(which docker-runc)_ ; sudo cp ./bundles/latest/binary-daemon/docker-runc $(which docker-runc)
sudo service docker start

Dont worry - we backed up the old binaries. They are still there but with an underscore added to its names (docker_).

Congratulation you now have an experimental docker with the ability to checkpoint a container and restore it.

Please note that experimental features are NOT ready for production

Checkpoint and Restore a Container

# create docker container
export cid=$(docker run -d --security-opt seccomp:unconfined busybox /bin/sh -c 'i=0; while true; do echo $i; i=$(expr $i + 1); sleep 1; done')

# container is started and prints a number every second
# display the output with 
docker logs $cid

# checkpoint the container
docker checkpoint create $cid checkpointname

# container is not running anymore
docker np

# lets pass some time to make sure

# resume container
docker start $cid --checkpoint=checkpointname

# print logs again
docker logs $cid