title: Compute -> Deployment

## Deployment ##

*This functionality depends on the `paramiko` library which is not installed by default when installing `apache-libcloud` package. You can be install it manually using pip - `pip install paramiko`.*

Deployment functionality allows you to create a node and after it has been
started install an SSH key and / or run arbitrary shell commands on it. It
works by first calling `create_node` and then after the node has been
fully started SSHing into the node and running a shell script on it.

We assume that a node has been fully started when a returned state is
`NodeState.RUNNING` and when it has a public IP address assigned.

Keep in mind that Libcloud is not a replacement for a configuration management
tool so it shouldn't be used as such.

### Provider Images and Default Usernames ###

Libcloud uses `root` username when running a command on the remote server. 
A lot of images use a different default username (e.g. `ubuntu` for some ubuntu AWS AMI's, `bitnatmi` for some Bitnami AWS AMI's, etc.).

This means deployment will fail if you don't specify a correct username using the `ssh_username` keyword argument like it's shown in the example 2.

### Example 1 - Deploying a Rackspace Node using password authentication and installing your SSH key and Puppet on it ###

    ::python
    from libcloud.compute.types import Provider
    from libcloud.compute.providers import get_driver
    from libcloud.compute.deployment import MultiStepDeployment, ScriptDeployment, SSHKeyDeployment
    import os

    RACKSPACE_USER = 'your username'
    RACKSPACE_KEY = 'your key'

    Driver = get_driver(Provider.RACKSPACE)
    conn = Driver(RACKSPACE_USER, RACKSPACE_KEY)

    # read your public key in
    # Note: This key will be added to the authorized keys for the root user
    # (/root/.ssh/authorized_keys)
    sd = SSHKeyDeployment(open(os.path.expanduser("~/.ssh/id_rsa.pub")).read())
    # a simple script to install puppet post boot, can be much more complicated.
    script = ScriptDeployment("apt-get -y install puppet")
    # a task that first installs the ssh key, and then runs the script
    msd = MultiStepDeployment([sd, script])

    images = conn.list_images()
    sizes = conn.list_sizes()

    # deploy_node takes the same base keyword arguments as create_node.
    node = conn.deploy_node(name='test', image=images[0], size=sizes[0], deploy=msd)
    # <Node: uuid=..., name=test, state=3, public_ip=['1.1.1.1'], provider=Rackspace ...>
    # the node is now booted, with your ssh key and puppet installed.


### Example 2 - Deploying an EC2 Node using SSH key authentication and installing Puppet on it ###

    ::python
    from libcloud.compute.types import Provider
    from libcloud.compute.providers import get_driver
    from libcloud.compute.deployment import ScriptDeployment

    EC2_ACCESS_ID = 'your access key'
    EC2_SECRET = 'your secret'

    Driver = get_driver(Provider.EC2_US_EAST)
    conn = Driver(EC2_ACCESS_ID, EC2_SECRET)

    # a simple script to install puppet post boot, can be much more complicated.
    script = ScriptDeployment("apt-get -y install puppet")

    # Ubuntu 10.04
    image = [i for i in driver.list_images() if i.id =='ami-09965860' ][0]
    size = [s for s in driver.list_sizes() if s.id == 't1.micro'][0]

    # Name of the SSH key which is automatically installed on the server.
    # Key needs to be generated and named in the AWS control panel.
    key_name = 'my_default'

    # Path to the private key created using the AWS control panel.
    key_path = '/home/user/path/to/key.pem'

    # deploy_node takes the same base keyword arguments as create_node.
    node = conn.deploy_node(name='test', image=image, size=size, deploy=script,
                            ssh_username='ubuntu', ssh_key=key_path,
                            ex_keyname=key_name)
    # <Node: uuid=..., name=test, state=3, public_ip=['1.1.1.1'], provider=EC2 ...>
    # the node is now booted, with puppet installed.