Using supernova

Passing commands to nova

The structure of a supernova command is relatively simple:

supernova [enviromment_name[,enviromment_name]...] [commands]

Here are some examples:

• Listing instances in the iad environment:

    supernova iad list

• Listing available images:

    supernova iad image-list

• Listing available flavors:

    supernova iad flavor-list

• Booting an instance::

    supernova iad boot --image image_uuid --flavor flavor_id myserver.example.com

You can also use a comma-separated list of environment names:

    supernova iad,dfw,ord list

You can use a regular expression for the environment if you enclose it in slashes:

    supernova /^rax/ list

The above command will execute nova list for every environment whose name starts with rax.

You can use supernova with long-running options and the output will be piped live to your terminal. For example, you can use --poll when you boot an instance and you'll see the novaclient output update as your instance is being built.

For debug output, supernova accepts --debug as a supernova option or as a novaclient option. Both of these are okay:

    supernova --debug iad list
    supernova iad list --debug

Be careful with sharing debug output since many clients will print credentials in plain text even if the credentials are not stored in plain text.

Custom supernova configuration file locations

You can specify a custom location for your supernova configuration file if you have it stored in a non-standard directory or if you need to name it differently:

    supernova -c ~/supernova/work.config prod list
    supernova -c ~/supernova/home.config prod list

Listing available supernova environments

There's a convenience function provided that will dump out your parsed supernova configuration file to the screen::

    supernova -l

This is a good way to test your configuration file syntax and diagnose problems. Keep in mind that any plain text credentials will be displayed on screen when you list environments (see the keyring documentation for more details).

If you're still using plain text credentials, now is a good time to stop using them. :)

Grouped environments

Starting in supernova 0.9.6, you can "group" environments and run commands across all of the environments in a group. Using the Rackspace example configuration, we can group the DFW, IAD and ORD environments into a group called "raxusa":

[dfw]
SUPERNOVA_GROUP=raxusa
...snip...

[ord]
SUPERNOVA_GROUP=raxusa
...snip...

[iad]
SUPERNOVA_GROUP=raxusa
...snip...

You can also use a comma-separated list for SUPERNOVA_GROUP:

[dfw]
SUPERNOVA_GROUP=raxusa,rackspace,dallas,usa
...snip...

[ord]
SUPERNOVA_GROUP=raxusa,rackspace,chicago,usa
...snip...

[iad]
SUPERNOVA_GROUP=raxusa,rackspace,virginia,usa
...snip...

Instead of referring to these environments one by one, you can now run commands across them as a group:

supernova raxusa list

This can be quite useful if you need to search multiple environments for an instance, or if you need to boot test instances in multiple datacenters. Just be careful with any actions that manipulate data, like rebuilds or instance deletions.

You can also use a comma-separated list of group names:

    supernova raxusa,raxuk list

There is a default group called all that contains all environments. You can use the all group without having to add SUPERNOVA_GROUP settings to your config file:

supernova all list

Using supernova with different executables

While supernova uses the nova executable by default, you can configure it to use any other executable when it runs. For example, you could use it to run glance, neutron, or keystone.

You can use the same executable for certain environments every time by adding OS_EXECUTABLE to your supernova configuration file:

[iadglance]
OS_EXECUTABLE=glance
...snip...

If you'd rather make a quick change at runtime, just use -x or --executable:

    supernova -x glance iadglance image-list

Checking the supernova version

As of supernova 1.0.5, you can use the --version argument to have supernova's version printed on the command line::

    $ supernova --version
    supernova 1.0.5