nova-docker

Docker driver for OpenStack Nova.

Free software: Apache license

Installation & Configuration

1. Install the python modules.

For example:

$ python setup.py install

Note: There are better and cleaner ways of managing Python modules, such as using distribution packages or 'pip'. The setup.py file and Debian's stdeb, for instance, may be used to create Debian/Ubuntu packages.

2. Enable the driver in Nova's configuration

In nova.conf:

compute_driver=novadocker.virt.docker.DockerDriver

3. Optionally tune site-specific settings.

In nova.conf:

[docker]
# Commented out. Uncomment these if you'd like to customize:
## vif_driver=novadocker.virt.docker.vifs.DockerGenericVIFDriver
## snapshots_directory=/var/tmp/my-snapshot-tempdir

Uploading Images to Glance

1. Enable the driver in Glance's configuration

In glance-api.conf:

container_formats=ami,ari,aki,bare,ovf,ova,docker

2. Save docker images to Glance

Images may now be saved directly to Glance:

$ docker pull busybox
$ docker save busybox | openstack image create busybox --public --container-format docker --disk-format raw

Note: At present, only administrators should be allowed to manage images. With devstack you can make yourself administrator by sourcing openrc as:

source openrc admin

Once done you can go back to a user:

source openrc demo

The name of the image in Glance should be explicitly set to the same name as the image as it is known to Docker. In the example above, an image has been tagged in Docker as 'busybox'. Matching this is the '--name busybox' argument to glance image-create. If these names do not align, the image will not be bootable.

Note: There should be a long lived process running in the docker image, otherwise the instance will not be able to spawn successfully. This can be done by using CMD or ENTRYPOINT in DockerFile:

https://docs.docker.com/reference/builder/

or specifing the command through glance image property 'os_command_line' for test:

glance image-update --property os_command_line='/usr/sbin/sshd -D' $IMAGE_ID

3. Generate a keypair

You can optionally create a keypair to use in your docker images:

nova keypair-add mykey > mykey.pem

4. Start a container

Start a new container. This uses the key created above:

nova boot --flavor m1.small --image busybox --key-name mykey test1

5. ssh into container

You can check the IP address of the container by using:

nova list

And then ssh into it:

ssh -i ../devstack/mykey.pem cirros@<IP ADDRESS>

Notes

Earlier releases of this driver required the deployment of a private docker registry. This is no longer required. Images are now saved and loaded from Glance.
Images loaded from Glance may do bad things. Only allow administrators to add images. Users may create snapshots of their containers, generating images in Glance -- these images are managed and thus safe.

Contact Us

Join us in #nova-docker on Freenode IRC

Features

TODO

startover/nova-docker