ironicclient是一个cli工具，用来和用户交互的。
首先写一个简单的例子，获取ironic所有的node节点：
from ironicclient import client
if __name__ == '__main__':
kwargs = {'os_username': 'ironic',
'os_password': 'IRONIC_PASSWORD',
'os_auth_url': 'http://192.168.1.72:5000/',
'os_tenant_name': 'services'}
ironic = client.get_client(1, **kwargs)
print ironic.node.list()
这里我们创建了一个client对象，这个对象是通过client类的get_client方法返回的，
这是一个工厂模式，下面看下get_client方法：
def get_client(api_version, os_auth_token=None, ironic_url=None,
os_username=None, os_password=None, os_auth_url=None,
os_project_id=None, os_project_name=None, os_tenant_id=None,
os_tenant_name=None, os_region_name=None,
os_user_domain_id=None, os_user_domain_name=None,
os_project_domain_id=None, os_project_domain_name=None,
os_service_type=None, os_endpoint_type=None,
insecure=None, timeout=None, os_cacert=None, ca_file=None,
os_cert=None, cert_file=None, os_key=None, key_file=None,
os_ironic_api_version=None, max_retries=None,
retry_interval=None, session=None, **ignored_kwargs):
os_service_type = os_service_type or 'baremetal'
os_endpoint_type = os_endpoint_type or 'publicURL'
project_id = (os_project_id or os_tenant_id)
project_name = (os_project_name or os_tenant_name)
kwargs = {
'os_ironic_api_version': os_ironic_api_version,
'max_retries': max_retries,
'retry_interval': retry_interval,
}
endpoint = ironic_url
cacert = os_cacert or ca_file
cert = os_cert or cert_file
key = os_key or key_file
if os_auth_token and endpoint:
kwargs.update({
'token': os_auth_token,
'insecure': insecure,
'ca_file': cacert,
'cert_file': cert,
'key_file': key,
'timeout': timeout,
})
elif os_auth_url:
auth_type = 'password'
auth_kwargs = {
'auth_url': os_auth_url,
'project_id': project_id,
'project_name': project_name,
'user_domain_id': os_user_domain_id,
'user_domain_name': os_user_domain_name,
'project_domain_id': os_project_domain_id,
'project_domain_name': os_project_domain_name,
}
if os_username and os_password:
auth_kwargs.update({
'username': os_username,
'password': os_password,
})
elif os_auth_token:
auth_type = 'token'
auth_kwargs.update({
'token': os_auth_token,
})
# Create new session only if it was not passed in
if not session:
loader = kaloading.get_plugin_loader(auth_type)
auth_plugin = loader.load_from_options(**auth_kwargs)
# Let keystoneauth do the necessary parameter conversions
session = kaloading.session.Session().load_from_options(
auth=auth_plugin, insecure=insecure, cacert=cacert,
cert=cert, key=key, timeout=timeout,
)
exception_msg = _('Must provide Keystone credentials or user-defined '
'endpoint and token')
if not endpoint:
if session:
try:
# Pass the endpoint, it will be used to get hostname
# and port that will be used for API version caching. It will
# be also set as endpoint_override.
endpoint = session.get_endpoint(
service_type=os_service_type,
interface=os_endpoint_type,
region_name=os_region_name
)
except Exception as e:
raise exc.AmbiguousAuthSystem(
exception_msg + _(', error was: %s') % e)
else:
# Neither session, nor valid auth parameters provided
raise exc.AmbiguousAuthSystem(exception_msg)
# Always pass the session
kwargs['session'] = session
return Client(api_version, endpoint, **kwargs)
中间这一大串可以先不看，主要是认证的一些信息。在get_cleint函数结尾，调用了
Client() 方法作为返回值。这里传入了三个参数：
- api_version
- endpoint
- **kwargs
其中api_version是1，endpoint是http://192.168.1.72:6385，kwargs保存了session的
信息：
{'os_ironic_api_version': None, 'session': <keystoneauth1.session.Session object at 0x2441690>, 'retry_interval': None, 'max_retries': None}
我们再来看看Client()方法的具体实现：
def Client(version, *args, **kwargs):
module = utils.import_versioned_module(version, 'client')
client_class = getattr(module, 'Client')
return client_class(*args, **kwargs)
这里module内容如下：
<module 'ironicclient.v1.client' from '/usr/lib/python2.7/site-packages/ironicclient/v1/client.pyc'>
后面的client_class使用反射的机制来获取Client类。简单的说就是调用文件/usr/lib/python2.7/site-packages/ironicclient/v1/client.py中的
Client类，并返回其对象。
再来看下Client类的具体实现：
class Client(object):
def __init__(self, *args, **kwargs):
"""Initialize a new client for the Ironic v1 API."""
if kwargs.get('os_ironic_api_version'):
kwargs['api_version_select_state'] = "user"
else:
# If the user didn't specify a version, use a cached version if
# one has been stored
host, netport = http.get_server(args[0])
saved_version = filecache.retrieve_data(host=host, port=netport)
if saved_version:
kwargs['api_version_select_state'] = "cached"
kwargs['os_ironic_api_version'] = saved_version
else:
kwargs['api_version_select_state'] = "default"
kwargs['os_ironic_api_version'] = DEFAULT_VER
self.http_client = http._construct_http_client(*args, **kwargs)
self.chassis = chassis.ChassisManager(self.http_client)
self.node = node.NodeManager(self.http_client)
self.port = port.PortManager(self.http_client)
self.driver = driver.DriverManager(self.http_client)
可以看出Client类的chassis，node，port，driver属性都是对应类的manager。
先看看NodeManager的实现：
class NodeManager(base.CreateManager):
resource_class = Node
_creation_attributes = ['chassis_uuid', 'driver', 'driver_info',
'extra', 'uuid', 'properties', 'name']
_resource_name = 'nodes'
def list(self, associated=None, maintenance=None, marker=None, limit=None,
detail=False, sort_key=None, sort_dir=None, fields=None,
provision_state=None, driver=None):
if limit is not None:
limit = int(limit)
if detail and fields:
raise exc.InvalidAttribute(_("Can't fetch a subset of fields "
"with 'detail' set"))
filters = utils.common_filters(marker, limit, sort_key, sort_dir,
fields)
if associated is not None:
filters.append('associated=%s' % associated)
if maintenance is not None:
filters.append('maintenance=%s' % maintenance)
if provision_state is not None:
filters.append('provision_state=%s' % provision_state)
if driver is not None:
filters.append('driver=%s' % driver)
path = ''
if detail:
path += 'detail'
if filters:
path += '?' + '&'.join(filters)
if limit is None:
return self._list(self._path(path), "nodes")
else:
return self._list_pagination(self._path(path), "nodes",
limit=limit)
...
我们看list方法，前面是一些过滤条件，因为我们没有穿limit参数，所有limit是None,
然后调用了_list()方法。这个是在父类里定义的。实现代码在：/usr/lib/python2.7/site-packages/ironicclient/common/base.py
def _list(self, url, response_key=None, obj_class=None, body=None):
resp, body = self.api.json_request('GET', url)
if obj_class is None:
obj_class = self.resource_class
data = self._format_body_data(body, response_key)
return [obj_class(self, res, loaded=True) for res in data if res]
我们可以看到，这里是发送了HTTP GET请求，然就将收到的数据格式化并返回。
这里的api是我们在前面传入的，使用http创建的一个client对象。
self.http_client = http._construct_http_client(*args, **kwargs)
...
self.node = node.NodeManager(self.http_client)