CS

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A simple, yet powerful CloudStack API client for python and the command-line.

• Async support.
• All present and future CloudStack API calls and parameters are supported.
• Syntax highlight in the command-line client if Pygments is installed.
• BSD license.

Installation

::

pip install cs

# with the colored output
pip install cs[highlight]

# with the async support
pip install cs[async]

# with both
pip install cs[async,highlight]

Usage

In Python:

.. code-block:: python

from cs import CloudStack

cs = CloudStack(endpoint='https://api.exoscale.ch/v1',
                key='cloudstack api key',
                secret='cloudstack api secret')

vms = cs.listVirtualMachines()

cs.createSecurityGroup(name='web', description='HTTP traffic')

From the command-line, this requires some configuration:

.. code-block:: console

cat $HOME/.cloudstack.ini

.. code-block:: ini

[cloudstack]
endpoint = https://api.exoscale.ch/v1
key = cloudstack api key
secret = cloudstack api secret
# Optional ca authority certificate
verify = /path/to/certs/exoscale_ca.crt
# Optional client PEM certificate
cert = /path/to/client_exoscale.pem
# If you need to pass the certificate and key as separate files
cert_key = /path/to/client_key.pem

Then:

.. code-block:: console

$ cs listVirtualMachines

.. code-block:: json

{
  "count": 1,
  "virtualmachine": [
    {
      "account": "...",
      ...
    }
  ]
}

.. code-block:: console

$ cs authorizeSecurityGroupIngress \
    cidrlist="0.0.0.0/0" endport=443 startport=443 \
    securitygroupname="blah blah" protocol=tcp

The command-line client polls when async results are returned. To disable polling, use the --async flag.

To find the list CloudStack API calls go to http://cloudstack.apache.org/api.html

Configuration

Configuration is read from several locations, in the following order:

• The CLOUDSTACK_ENDPOINT, CLOUDSTACK_KEY, CLOUDSTACK_SECRET and CLOUDSTACK_METHOD environment variables,
• A CLOUDSTACK_CONFIG environment variable pointing to an .ini file,
• A CLOUDSTACK_VERIFY (optional) environment variable pointing to a CA authority cert file,
• A CLOUDSTACK_CERT (optional) environment variable pointing to a client PEM cert file,
• A CLOUDSTACK_CERT_KEY (optional) environment variable pointing to a client PEM certificate key file,
• A cloudstack.ini file in the current working directory,
• A .cloudstack.ini file in the home directory.

To use that configuration scheme from your Python code:

.. code-block:: python

from cs import CloudStack, read_config

cs = CloudStack(**read_config())

Note that read_config() can raise SystemExit if no configuration is found.

CLOUDSTACK_METHOD or the method entry in the configuration file can be used to change the HTTP verb used to make CloudStack requests. By default, requests are made with the GET method but CloudStack supports POST requests. POST can be useful to overcome some length limits in the CloudStack API.

CLOUDSTACK_TIMEOUT or the timeout entry in the configuration file can be used to change the HTTP timeout when making CloudStack requests (in seconds). The default value is 10.

CLOUDSTACK_RETRY or the retry entry in the configuration file (integer) can be used to retry list and queryAsync requests on failure. The default value is 0, meaning no retry.

CLOUDSTACK_JOB_TIMEOUT or the `job_timeoutentry in the configuration file (float) can be used to set how long an async call is retried assumingfetch_resultis set to true). The default value isNone``, it waits forever.

CLOUDSTACK_POLL_INTERVAL or the poll_interval entry in the configuration file (number of seconds, float) can be used to set how frequently polling an async job result is done. The default value is 2.

CLOUDSTACK_EXPIRATION or the expiration entry in the configuration file (integer) can be used to set how long a signature is valid. By default, it picks 10 minutes but may be deactivated using any negative value, e.g. -1.

CLOUDSTACK_DANGEROUS_NO_TLS_VERIFY or the dangerous_no_tls_verify entry in the configuration file (boolean) can be used to deactivate the TLS verification made when using the HTTPS protocol.

Multiple credentials can be set in .cloudstack.ini. This allows selecting the credentials or endpoint to use with a command-line flag.

.. code-block:: ini

[cloudstack]
endpoint = https://some-host/api/v1
key = api key
secret = api secret

[exoscale]
endpoint = https://api.exoscale.ch/v1
key = api key
secret = api secret

Usage::

$ cs listVirtualMachines --region=exoscale

Optionally CLOUDSTACK_REGION can be used to overwrite the default region cloudstack.

For the power users that don't want to put any secrets on disk, CLOUDSTACK_OVERRIDES let you pick which key will be set from the environment even if present in the ini file.

Pagination

CloudStack paginates requests. cs is able to abstract away the pagination logic to allow fetching large result sets in one go. This is done with the fetch_list parameter::

$ cs listVirtualMachines fetch_list=true

Or in Python::

cs.listVirtualMachines(fetch_list=True)

Tracing HTTP requests

Once in a while, it could be useful to understand, see what HTTP calls are made under the hood. The trace flag (or CLOUDSTACK_TRACE) does just that::

$ cs --trace listVirtualMachines

$ cs -t listZones

Async client

cs provides the AIOCloudStack class for async/await calls in Python 3.5+.

.. code-block:: python

import asyncio
from cs import AIOCloudStack, read_config

cs = AIOCloudStack(**read_config())

async def main():
   vms = await cs.listVirtualMachines(fetch_list=True)
   print(vms)

asyncio.run(main())

Async deployment of multiple VMs

.. code-block:: python

import asyncio
from cs import AIOCloudStack, read_config

cs = AIOCloudStack(**read_config())

machine = {"zoneid": ..., "serviceofferingid": ..., "templateid": ...}

async def main():
   tasks = asyncio.gather(*(cs.deployVirtualMachine(name=f"vm-{i}",
                                                    **machine,
                                                    fetch_result=True)
                            for i in range(5)))

   results = await tasks

   # Destroy all of them, but skip waiting on the job results
   await asyncio.gather(*(cs.destroyVirtualMachine(id=result['virtualmachine']['id'])
                          for result in results))

asyncio.run(main())

Release Procedure

.. code-block:: shell-session

mktmpenv -p /usr/bin/python3
pip install -U twine wheel build
cd exoscale/cs
rm -rf build dist
python -m build
twine upload dist/*

Links

• CloudStack API: http://cloudstack.apache.org/api.html
• Example of use: Get Started with the exoscale API client <https://www.exoscale.com/syslog/2016/02/23/get-started-with-the-exoscale-api-client/>_