In order to beef up my DevOps skills I decided to see if I could connect through a REST API using python. I found out that there are some python modules built specifically for this.
One such module is called novaclient. You would need pip on your machine to do this.
sudo easy_install pip
Then you can use pip to install the nova client.
sudo pip install python-novaclient
If you want to look at the details of the python module it can be found here:
https://github.com/openstack/python-novaclient
This is where I look more into the code and found out it’s capabilities
You can pass parameters to the “client” function.
def __init__(self, username=None, api_key=None, project_id=None,
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auth_url=None, insecure=False, timeout=None,
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proxy_tenant_id=None, proxy_token=None, region_name=None,
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endpoint_type='publicURL', extensions=None,
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service_type='compute', service_name=None,
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volume_service_name=None, timings=False, bypass_url=None,
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os_cache=False, no_cache=True, http_log_debug=False,
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auth_system='keystone', auth_plugin=None, auth_token=None,
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cacert=None, tenant_id=None, user_id=None,
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connection_pool=False, session=None, auth=None,
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completion_cache=None):
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First I built a login function that will pass these parameters which I can call from my main script.
login.py
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def get_nova_credentials():
cred = {}
cred['username'] = "admin"
cred['api_key'] = “password”
cred['auth_url'] = "http://<openstack-ip>:5000/v2.0"
cred['project_id'] = "demo"
cred['service_type'] = "compute"
return cred
Now in my main script I can import the client and my credentials
server-list.py
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#!/usr/bin/env python
import novaclient
from novaclient.v1_1 import client
from login import get_nova_credentials
credentials = get_nova_credentials()
#Pass credentials to the client function.
nova = client.Client(**credentials)
#grab the list of servers and print out the id, names and status
vms = nova.servers.list(detailed=True)
for vm in vms:
print vm.id, vm.name, vm.status
—————
script in action.
laptop$ python server-list.py
f5801333-5d81-496c-b257-e589ca36e944 Cirros-VM2 ACTIVE
098270e0-e5fb-4ea6-a1f1-2dfca11a409d Cirros-VM1 ACTIVE
So what's the big deal? Why do this when you can use the Horizon web ui?
Now that I have a basic understanding of this module, I can start automating things such as building VMs, virtual networks, etc in a scaled and precise manner.
