Vmck

Vmck is a virtual machine service that runs QEMU and Docker images in a Nomad cluster.

It can be used as a provider for Vagrant:

vagrant plugin install vagrant-vmck
curl -OL https://github.com/mgax/vagrant-vmck/raw/master/example_box/Vagrantfile
vagrant up
vagrant ssh

And it has its own CLI:

pipenv run ./manage.py createjob
pipenv run ./manage.py ssh 1
pipenv run ./manage.py kill 1

Installation

Using docker

docker run --detach --restart always \
  --name cluster \
  --volume /opt/cluster/var:/opt/cluster/var \
  --volume /opt/vmck/var:/opt/vmck/var \
  --volume /var/run/docker.sock:/var/run/docker.sock:ro \
  --privileged \
  --net host \
  --env NOMAD_CLIENT_INTERFACE=wg0 \
  --env HOSTNAME=127.0.0.1 \
  --env SECRET_KEY=foo \
  mgax/vmck

Here you can add different --env options with arguments matching {root}/vmck/settings.py and {root}/vmck/base_settings.py to suit your preferences.

Then go to consul (http://localhost:8500/ui/dc1/services) and wait for the health check lights to turn green.

Running locally

• Needs a Nomad instance alongside Consul(liquidinvestigations/cluster is easy to set-up and has both Nomad and Consul)
• If you are using the above mentioned cluster you can skip this step if not add the following to your .env file:

SECRET_KEY=change_me
CONSUL_URL=your_consul_url
NOMAD_URL=your_nomad_url

• By default the docker backend is selected. You can choose qemu by adding BACKEND=qemu to your .env file
• Then install dependencies and run migrations:

pipenv install
pipenv run ./manage.py migrate

• Then you can run the server:

pipenv run ./manage.py runserver

Running VMCK on your cluster

You need Nomad cluster with Consul. To start vmck in your Nomad cluster:

export NOMAD_URL='your_nomad_url' # skip this line if you are using liquidinvestigations/cluster
cd examples
./cluster.py

Now VMCK is a job in your Nomad cluster.

Qemu VM images

Now all images are built using vmck/image-builder. Please refer to it on how to build, provision and test your image.

Testing

Requirements

• Nomad instance alongside Consul(liquidinvestigations/cluster is easy to set-up and has both Nomad and Consul)
• If you are using the above mentioned cluster you can skip this step if not add the following to your .env file:

TESTING_CONSUL_URL=your_consul_url
TESTING_NOMAD_URL=your_nomad_url

• By default the docker backend is selected. You can choose qemu by adding TESTING_BACKEND=qemu to your .env file

Docker backend

The docker backend uses vmck/mock as it's default image. The only way to change that is to modify {root}/vmck/backends/docker.py docker_vm_task.config.image. We do not recommend it as the docker backend is for testing purposes only. Check vmck/vagrant-vmck and Vagrant on how to provision, test and use the job that vmck will start.

Qemu backend

This requires a bit more configuration. Qemu images are retrieved through a nginx server. You need to have one. Here is an example of a .hcl job specification that you can use to start the server on your Nomad cluster. You need to set TESTING_QEMU_IMAGE_PATH_PREFIX in .env file to the url of your nginx server. To use the image of your choosing set image_path option in your POST request to the name of your desired image.

Doing tests

With a Nomad cluster up and running, run pipenv run pytest, and enjoy.

Troubleshooting

• QEMU fails to start with error qemu-system-x86_64: Invalid host forwarding rule 'tcp:${attr.unique.network.ip-address}:10674-:22' (Bad host address): the host address has changed (e.g. because it moved to a different WiFi hotspot). Restart Nomad and it should pick up the new address.