Using the Client Programmatically

Authentication

Authenticating is necessary to use every feature of the client (except to discover available versions).

To create the client, create an instance of the Dbaas (Database as a Service) class. The auth url, auth user, key, and tenant ID must be specified in the call to the constructor.

from troveclient import Dbaas
global AUTH_URL

client = Dbaas("jsmith", "abcdef", tenant="12345",
              auth_url=AUTH_URL)
client.authenticate()

The default authentication strategy assumes a Keystone compliant auth system. For Rackspace auth, use the keyword argument “auth_strategy=’rax’”.

Versions

You can discover the available versions by querying the versions property as follows:

versions = client.versions.index("http://localhost:8779")

The “index” method returns a list of Version objects which have the ID as well as a list of links, each with a URL to use to reach that particular version.

for version in versions:
    print(version.id)
    for link in version.links:
        if link['rel'] == 'self':
            print("    %s" % link['href'])

v1.0
    http://localhost:8779/v1.0/

Instances

The following example creates a 512 MB instance with a 1 GB volume:

client.authenticate()
flavor_id = "1"
volume = {'size':1}
databases = [{"name": "my_db",
              "character_set": "latin2",           # These two fields
              "collate": "latin2_general_ci"}]     # are optional.
users = [{"name": "jsmith", "password": "12345",
          "databases": [{"name": "my_db"}]
         }]
instance = client.instances.create("My Instance", flavor_id, volume,
                                   databases, users)

To retrieve the instance, use the “get” method of “instances”:

updated_instance = client.instances.get(instance.id)
print(updated_instance.name)
print("   Status=%s Flavor=%s" %
          (updated_instance.status, updated_instance.flavor['id']))

My Instance
   Status=BUILD Flavor=1

You can delete an instance by calling “delete” on the instance object itself, or by using the delete method on “instances.”

# Wait for the instance to be ready before we delete it.
import time
from troveclient.exceptions import NotFound

while instance.status == "BUILD":
    instance.get()
    time.sleep(1)
print("Ready in an %s state." % instance.status)
instance.delete()
# Delete and wait for the instance to go away.
while True:
    try:
        instance = client.instances.get(instance.id)
        assert instance.status == "SHUTDOWN"
    except NotFound:
        break

Ready in an ACTIVE state.

Listing instances and Pagination

To list all instances, use the list method of “instances”:

instances = client.instances.list()

Lists paginate after twenty items, meaning you’ll only get twenty items back even if there are more. To see the next set of items, send a marker. The marker is a key value (in the case of instances, the ID) which is the non-inclusive starting point for all returned items.

The lists returned by the client always include a “next” property. This can be used as the “marker” argument to get the next section of the list back from the server. If no more items are available, then the next property is None.

# There are currently 30 instances.

instances = client.instances.list()
print(len(instances))
print(instances.next is None)

instances2 = client.instances.list(marker=instances.next)
print(len(instances2))
print(instances2.next is None)

20
False
10
True