One of our top goals for LXC upstream work during the Ubuntu 12.10 development cycle was reworking the LXC library and turn it from a private library mostly used by the other lxc-* commands into something that’s easy for developers to work with and is accessible from other languages with some bindings.
Although the current implementation isn’t complete enough to consider the API stable and some changes will still happen to it over the months to come, we have pushed the initial implementation to the LXC staging branch on github and put it into the lxc package of Ubuntu 12.10.
The initial version comes with a python3 binding packaged as python3-lxc, that’s what I’ll use now to give you an idea of what’s possible with the API. Note that as we don’t have full user namespaces support at the moment, any code using the LXC API needs to run as root.
First, let’s start with the basics, creating a container, starting it, getting its IP and stopping it:
#!/usr/bin/python3
import lxc
container = lxc.Container("my_container")
container.create("ubuntu", {"release": "precise", "architecture": "amd64"})
container.start()
print(container.get_ips(timeout=10))
container.shutdown(timeout=10)
container.destroy()
So, pretty simple.
It’s also possible to modify the container’s configuration using the .get_config_item(key) and .set_config_item(key, value) functions. For those keys supporting multiple values, a list will be returned and a list will be accepted as a value by .set_config_item.
Network configuration can be accessed through the .network property which is essentially a list of all network interfaces of the container, properties can be changed that way or through .set_config_item and saved to the config file with .save_config().
The API isn’t terribly well documented at this point, help messages are present for all functions but there’s no generated html help yet.
To get a better idea of the functions exported by the API, you may want to look at the API test script. This script uses all the functions and properties exported by the python module so it should be a reasonable reference.