一、简介
openstack的各个模块中，都有相应的客户端模块实现，其作用是为用户访问具体模块提供了接口，并且也作为模块之间相互访问的途径。Cinder也一样，有着自己的cinder-client。
二、argparse简单介绍
argparse是python用于解析命令行参数和选项的标准模块，作为optparse的一个替代被添加到Python2.7。Cinder-client主要就是调用了argparse这个工具包。
使用步骤：
import argparse
parser = argparse.ArgumentParser()
parser.add_argument()
parser.parse_args()
首先导入该模块；然后创建一个解析对象；然后向该对象中添加你要关注的命令行参数和选项，每一个add_argument方法对应一个你要关注的参数或选项；最后调用parse_args()方法进行解析；解析成功之后即可使用。
方法 ArgumentParser(prog=None, usage=None,description=None, epilog=None, parents=[],formatter_class=argparse.HelpFormatter, prefix_chars='-',fromfile_prefix_chars=None, argument_default=None,conflict_handler='error', add_help=True)
这些参数都有默认值，当调用 parser.print_help()或者运行程序时，由于参数不正确(此时python解释器其实也是调用了pring_help()方法)时，会打印这些描述信息，一般只需要传递description参数
方法add_argument(name or flags...[, action][, nargs][, const][, default][, type][, choices][, required][, help][, metavar][, dest])
其中：
name or flags：命令行参数名或者选项，如上面的address或者-p,--port.其中命令行参数如果没给定，且没有设置defualt，则出错。但是如果是选项的话，则设置为None。，parse_args()运行时，会用'-'来认证可选参数，剩下的即为位置参数
nargs：命令行参数的个数，一般使用通配符表示，其中，'?'表示只用一个，'*'表示0到多个，'+'表示至少一个。nargs='*' 表示参数可设置零个或多个；nargs=' '+' 表示参数可设置一个或多个；nargs='?'表示参数可设置零个或一个
default：默认值。
type：参数的类型，默认是字符串string类型，还有float、int等类型。
help：和ArgumentParser方法中的参数作用相似，出现的场合也一致。
dest：如果提供dest，例如dest="a"，那么可以通过args.a访问该参数
action：参数出发的动作
store：保存参数，默认
store_const：保存一个被定义为参数规格一部分的值（常量），而不是一个来自参数解析而来的值。
store_ture/store_false：保存相应的布尔值
append：将值保存在一个列表中。
append_const：将一个定义在参数规格中的值（常量）保存在一个列表中。
count：参数出现的次数
parser.add_argument("-v", "--verbosity", action="count", default=0, help="increase output verbosity")
version：打印程序版本信息
choice：允许的参数值
三、cinderclient代码入口查找
第一种方式:
D:官网代码python-cinderclient-stable-pikesetup.cfg
[entry_points]
console_scripts =
cinder = cinderclient.shell:main
第二种方式：
[root@test bin]# pwd
/usr/bin
[root@test bin]# ls |grep cinder
cinder
cinder-all
cinder-api
cinder-backup
cinder-manage
cinder-rootwrap
cinder-rtstool
cinder-scheduler
cinder-volume
cinder-volume-usage-audit
[root@test bin]# cat cinder
#!/usr/bin/python
# PBR Generated from u'console_scripts'
import sys
from cinderclient.shell import main
if __name__ == "__main__":
sys.exit(main())
[root@test bin]#
四、cinderclient代码分析
D:官网代码python-cinderclient-stable-pikecinderclientshell.py
def main():
try:
if sys.version_info >= (3, 0):-----sys.version获取python的版本，默认情况下， 使用系统自带的python版本，python2.6或者python 2.7
"""
>>> print sys.version_info
(2, 6, 6, 'final', 0)
>>>
"""
OpenStackCinderShell().main(sys.argv[1:])---sys.argv[1:]，输入的cinder命令行，sys.argv[0]表示程序本身，sys.argv[1:]表示 输入的参数
else:
OpenStackCinderShell().main([encodeutils.safe_decode(item)----走如下分支，步骤一
for item in sys.argv[1:]])
except KeyboardInterrupt:
print("... terminating cinder client", file=sys.stderr)
sys.exit(130)
except Exception as e:
logger.debug(e, exc_info=1)
print("ERROR: %s" % six.text_type(e), file=sys.stderr)
sys.exit(1)
对步骤一进行详解
from cinderclient import api_versions
from cinderclient import client
D:官网代码python-cinderclient-stable-pikecinderclientshell.py
class OpenStackCinderShell(object):
def __init__(self):
self.ks_logger = None
self.client_logger = None
def main(self, argv):
# Parse args once to find version and debug settings
解析args参数一次，查找version和debug设置信息
parser = self.get_base_parser()
"""
get_base_parser：获取基本的命令行解析器;调用add_argument方法实现添加具体命令行参数；
构造参数解析类ArgumentParser的实例parser，然后通过实例调用方法parser.add_argument增加一些固有的参数,比如:--debug,--help，
--os_auth_type等参数
"""
(options, args) = parser.parse_known_args(argv)
"""
parse_known_args()方法的作用就是当仅获取到基本设置时，如果运行命令中传入了之后才会获取到的其他配置，不会报错；
而是将多出来的部分保存起来，留到后面使用，解析的参数按属性的方式存储到Namespace对象；
options的值为命名空间namespace的对象
"""
self.setup_debugging(options.debug)----打开debug信息
api_version_input = True
self.options = options
do_help = ('help' in argv) or (-----查看是不是需要对命令行进行help查询
'--help' in argv) or ('-h' in argv) or not argv
#确定使用API的版本，默认情况下，是版本3
if not options.os_volume_api_version:
api_version = api_versions.get_api_version(
DEFAULT_MAJOR_OS_VOLUME_API_VERSION)
else:
api_version = api_versions.get_api_version(
options.os_volume_api_version)
# build available subcommands based on version
#根据api版本号，去查找其对应的版本的扩展版本，其实本质上就是获取
D:官网代码python-cinderclient-stable-pikecinderclientv2contriblist_extensions.py模块中的类
major_version_string = "%s" % api_version.ver_major
self.extensions = client.discover_extensions(major_version_string)
self._run_extension_hooks('__pre_parse_args__')
#基于版本api版本，创建对应的子命令解释器，同时根据对应的api_version版本，加载
D:官网代码python-cinderclient-stable-pikecinderclient不同版本的shell.py文件
D:官网代码python-cinderclient-stable-pikecinderclientv2shell.py模块
subcommand_parser = self.get_subcommand_parser(api_version,
do_help, args)
self.parser = subcommand_parser
if options.help or not argv:---如果命令行后面跟的是help命令，那么就打印该命令的help信息，直接返回
subcommand_parser.print_help()
return 0
argv = self._delimit_metadata_args(argv)
# 命令行参数的解析；
args = subcommand_parser.parse_args(argv)
self._run_extension_hooks('__post_parse_args__', args)
# Short-circuit and deal with help right away.
if args.func == self.do_help:
self.do_help(args)
return 0
elif args.func == self.do_bash_completion:
self.do_bash_completion(args)
return 0
#提取命令行参数中的基本的租户等信息存放到一个元祖里，为后面方法的调用做具体参数的准备
(os_username, os_password, os_tenant_name, os_auth_url,
os_region_name, os_tenant_id, endpoint_type,
service_type, service_name, volume_service_name, os_endpoint,
cacert, os_auth_type) = (
args.os_username, args.os_password,
args.os_tenant_name, args.os_auth_url,
args.os_region_name, args.os_tenant_id,
args.os_endpoint_type,
args.service_type, args.service_name,
args.volume_service_name,
args.os_endpoint, args.os_cacert,
args.os_auth_type)
auth_session = None
#对参数的认证权限的一些处理，比如是否提供租户、是否提供密码等
if os_auth_type and os_auth_type != "keystone":
auth_plugin = loading.load_auth_from_argparse_arguments(
self.options)
auth_session = loading.load_session_from_argparse_arguments(
self.options, auth=auth_plugin)
else:
auth_plugin = None
if not service_type:
service_type = client.SERVICE_TYPES[major_version_string]
# FIXME(usrleon): Here should be restrict for project id same as
# for os_username or os_password but for compatibility it is not.
# V3 stuff
project_info_provided = ((self.options.os_tenant_name or
self.options.os_tenant_id) or
(self.options.os_project_name and
(self.options.os_project_domain_name or
self.options.os_project_domain_id)) or
self.options.os_project_id)
# NOTE(e0ne): if auth_session exists it means auth plugin created
# session and we don't need to check for password and other
# authentification-related things.
if not utils.isunauthenticated(args.func) and not auth_session:
if not os_password:
# No password, If we've got a tty, try prompting for it
if hasattr(sys.stdin, 'isatty') and sys.stdin.isatty():
# Check for Ctl-D
try:
os_password = getpass.getpass('OS Password: ')
# Initialize options.os_password with password
# input from tty. It is used in _get_keystone_session.
options.os_password = os_password
except EOFError:
pass
# No password because we didn't have a tty or the
# user Ctl-D when prompted.
if not os_password:
raise exc.CommandError("You must provide a password "
"through --os-password, "
"env[OS_PASSWORD] "
"or, prompted response.")
if not project_info_provided:
raise exc.CommandError(_(
"You must provide a tenant_name, tenant_id, "
"project_id or project_name (with "
"project_domain_name or project_domain_id) via "
" --os-tenant-name (env[OS_TENANT_NAME]),"
" --os-tenant-id (env[OS_TENANT_ID]),"
" --os-project-id (env[OS_PROJECT_ID])"
" --os-project-name (env[OS_PROJECT_NAME]),"
" --os-project-domain-id "
"(env[OS_PROJECT_DOMAIN_ID])"
" --os-project-domain-name "
"(env[OS_PROJECT_DOMAIN_NAME])"
))
if not os_auth_url:
raise exc.CommandError(
"You must provide an authentication URL "
"through --os-auth-url or env[OS_AUTH_URL].")
if not project_info_provided:
raise exc.CommandError(_(
"You must provide a tenant_name, tenant_id, "
"project_id or project_name (with "
"project_domain_name or project_domain_id) via "
" --os-tenant-name (env[OS_TENANT_NAME]),"
" --os-tenant-id (env[OS_TENANT_ID]),"
" --os-project-id (env[OS_PROJECT_ID])"
" --os-project-name (env[OS_PROJECT_NAME]),"
" --os-project-domain-id "
"(env[OS_PROJECT_DOMAIN_ID])"
" --os-project-domain-name "
"(env[OS_PROJECT_DOMAIN_NAME])"
))
if not os_auth_url and not auth_plugin:
raise exc.CommandError(
"You must provide an authentication URL "
"through --os-auth-url or env[OS_AUTH_URL].")
#没有提供认证会话的，那么与keystone建立认证会话
if not auth_session:
auth_session = self._get_keystone_session()
insecure = self.options.insecure
self.cs = client.Client(---------------步骤二，本质上是一个http请求
api_version, os_username,
os_password, os_tenant_name, os_auth_url,
region_name=os_region_name,
tenant_id=os_tenant_id,
endpoint_type=endpoint_type,
extensions=self.extensions,
service_type=service_type,
service_name=service_name,
volume_service_name=volume_service_name,
bypass_url=os_endpoint,
retries=options.retries,
http_log_debug=args.debug,
insecure=insecure,
cacert=cacert, auth_system=os_auth_type,
auth_plugin=auth_plugin,
session=auth_session,
logger=self.ks_logger if auth_session else self.client_logger)
try:
# 如果所要调用的方法没有标志为unauthenticated，则需要进行身份验证操作；
if not utils.isunauthenticated(args.func):
self.cs.authenticate()
except exc.Unauthorized:
raise exc.CommandError("OpenStack credentials are not valid.")
except exc.AuthorizationFailure:
raise exc.CommandError("Unable to authorize user.")
endpoint_api_version = None
# Try to get the API version from the endpoint URL. If that fails fall
# back to trying to use what the user specified via
# --os-volume-api-version or with the OS_VOLUME_API_VERSION environment
# variable. Fail safe is to use the default API setting.
try:
endpoint_api_version =
self.cs.get_volume_api_version_from_endpoint()
except exc.UnsupportedVersion:
endpoint_api_version = options.os_volume_api_version
if api_version_input:
logger.warning("Cannot determine the API version from "
"the endpoint URL. Falling back to the "
"user-specified version: %s",
endpoint_api_version)
else:
logger.warning("Cannot determine the API version from the "
"endpoint URL or user input. Falling back "
"to the default API version: %s",
endpoint_api_version)
profile = osprofiler_profiler and options.profile
if profile:
osprofiler_profiler.init(options.profile)
try:
args.func(self.cs, args)----实现根据解析的命令行参数调用具体的方法，假如使用的命令行为cinder list,该处args.func = do_list，
说明这里调用的具体方法是do_list；
finally:
if profile:
trace_id = osprofiler_profiler.get().get_base_id()
print("Trace ID: %s" % trace_id)
print("To display trace use next command:
"
"osprofiler trace show --html %s " % trace_id)
对步骤二详解
D:官网代码python-cinderclient-stable-pikecinderclientclient.py
def Client(version, *args, **kwargs):
"""Initialize client object based on given version."""
api_version, client_class = _get_client_class_and_version(version)----对步骤2.1 详解根据api版本version版本号，获取对应目录下的Client函数
return client_class(api_version=api_version,*args, **kwargs)-------对步骤2.2的详解
对步骤2.1详解
D:官网代码python-cinderclient-stable-pikecinderclientclient.py
def _get_client_class_and_version(version):
if not isinstance(version, api_versions.APIVersion):
version = api_versions.get_api_version(version)
else:
api_versions.check_major_version(version)
if version.is_latest():
raise exceptions.UnsupportedVersion(
_("The version should be explicit, not latest."))
return version, importutils.import_class(
"cinderclient.v%s.client.Client" % version.ver_major)
对步骤2.2 的详解---假如使用的版本为v2版本
D:官网代码python-cinderclient-stable-pikecinderclientv2client.py
from cinderclient import client
from cinderclient import api_versions
from cinderclient.v2 import availability_zones
from cinderclient.v2 import cgsnapshots
from cinderclient.v2 import consistencygroups
from cinderclient.v2 import capabilities
from cinderclient.v2 import limits
from cinderclient.v2 import pools
from cinderclient.v2 import qos_specs
from cinderclient.v2 import quota_classes
from cinderclient.v2 import quotas
from cinderclient.v2 import services
from cinderclient.v2 import volumes
from cinderclient.v2 import volume_snapshots
from cinderclient.v2 import volume_types
from cinderclient.v2 import volume_type_access
from cinderclient.v2 import volume_encryption_types
from cinderclient.v2 import volume_backups
from cinderclient.v2 import volume_backups_restore
from cinderclient.v2 import volume_transfers
class Client(object):
def __init__(self, username=None, api_key=None, project_id=None,
auth_url='', insecure=False, timeout=None, tenant_id=None,
proxy_tenant_id=None, proxy_token=None, region_name=None,
endpoint_type='publicURL', extensions=None,
service_type='volumev2', service_name=None,
volume_service_name=None, bypass_url=None, retries=0,
http_log_debug=False, cacert=None, auth_system='keystone',
auth_plugin=None, session=None, api_version=None,
logger=None, **kwargs):
# FIXME(comstud): Rename the api_key argument above when we
# know it's not being used as keyword argument
password = api_key
self.version = '2.0'
self.limits = limits.LimitsManager(self)
# extensions------引入统一目录下，不同资源的管理类
self.volumes = volumes.VolumeManager(self)
self.volume_snapshots = volume_snapshots.SnapshotManager(self)
self.volume_types = volume_types.VolumeTypeManager(self)
self.volume_type_access =
volume_type_access.VolumeTypeAccessManager(self)
self.volume_encryption_types =
volume_encryption_types.VolumeEncryptionTypeManager(self)
self.qos_specs = qos_specs.QoSSpecsManager(self)
self.quota_classes = quota_classes.QuotaClassSetManager(self)
self.quotas = quotas.QuotaSetManager(self)
self.backups = volume_backups.VolumeBackupManager(self)
self.restores = volume_backups_restore.VolumeBackupRestoreManager(self)
self.transfers = volume_transfers.VolumeTransferManager(self)
self.services = services.ServiceManager(self)
self.consistencygroups = consistencygroups.
ConsistencygroupManager(self)
self.cgsnapshots = cgsnapshots.CgsnapshotManager(self)
self.availability_zones =
availability_zones.AvailabilityZoneManager(self)
self.pools = pools.PoolManager(self)
self.capabilities = capabilities.CapabilitiesManager(self)
self.api_version = api_version or api_versions.APIVersion(self.version)
# Add in any extensions...
if extensions:
for extension in extensions:
if extension.manager_class:
setattr(self, extension.name,
extension.manager_class(self))
if not logger:
logger = logging.getLogger(__name__)
self.client = client._construct_http_client(----本质上就是调用http模块的,建立session连接，同时拼接url的请求头，请求体
username=username,
password=password,
project_id=project_id,
auth_url=auth_url,
insecure=insecure,
timeout=timeout,
tenant_id=tenant_id,
proxy_tenant_id=tenant_id,
proxy_token=proxy_token,
region_name=region_name,
endpoint_type=endpoint_type,
service_type=service_type,
service_name=service_name,
volume_service_name=volume_service_name,
bypass_url=bypass_url,
retries=retries,
http_log_debug=http_log_debug,
cacert=cacert,
auth_system=auth_system,
auth_plugin=auth_plugin,
session=session,
api_version=self.api_version,
logger=logger,
**kwargs)
def authenticate(self):
"""Authenticate against the server.
Normally this is called automatically when you first access the API,
but you can call this method to force authentication right now.
Returns on success; raises :exc:`exceptions.Unauthorized` if the
credentials are wrong.
"""
self.client.authenticate()
def get_volume_api_version_from_endpoint(self):
return self.client.get_volume_api_version_from_endpoint()
五、添加一个新的命令行，这个命令行的功能为获取卷的连接信息，
1)命令行设计的样式如下所示：
cinder create-target volume_id hostname ip initiator usage: cinder create [--platform <platform>] [--do_local_attach <do_local_attach>] [--os_type <os_type>] [--multipath <multipath>] [<volume_id>] [<host_ip >] [<host_name>] [<initiator>] Creates a volume target. Positional arguments: <volume_id> volume uuid <host_ip > host ip ,which attach volume <host_name> host name ,which attach volume <initiator> host iscsi client,which attach volume Optional arguments: --platform <platform> host architecture ,which attach volume.Default=x86_64 --do_local_attach <do_local_attach> if or not attach volume.Default=None --os_type <os_type> host operation system,whiic attach volume.Default=linux2 --multipath <multipath> if or not iscsi multipath.Default=None
2）代码实现，在v2版本的shell.py文件中新增一个do_create_target函数
D:官网代码python-cinderclient-stable-ocatacinderclientv2shell.py
@utils.arg('volume',
metavar='<volume_id>',
help='volume uuid')
@utils.arg('host_ip',
metavar='<host_ip>',
help='host ip ,which attach volume')
@utils.arg('host_name',
metavar='<host_name>',
help='host name ,which attach volume')
@utils.arg('initiator',
metavar='<initiator>',
help='host iscsi client,which attach volume')
@utils.arg('--platform',
metavar='<platform>',
default='x86_64',
help='host architecture ,which attach volume.Default=x86_64')
@utils.arg('--do_local_attach',
metavar='<do_local_attach>',
default='false',
help='if or not attach volume.Default=false')
@utils.arg('--os_type',
metavar='<os_type>',
default='linux2',
help='host operation system,whiic attach volume.Default=linux2')
@utils.arg('--multipath',
metavar='<multipath>',
default='false',
help='if or not iscsi multipath.Default=false')
def do_create_target(cs,args):
"""create volume iscsi target."""
volume_id=args.volume
connector={}
connector['ip']=args.host_ip
connector['host']=args.host_name
connector['initiator']=args.initiator
connector['platform']=args.platform
connector['do_local_attach']=args.do_local_attach
connector['os_type']=args.os_type
connector['multipath']=args.multipath
info=cs.volumes.initialize_connection(volume_id,connector)
utils.print_dict(info)
输出内容如下：
[root@test ~]# cinder help create-target
usage: cinder create-target [--platform <platform>]
[--do_local_attach <do_local_attach>]
[--os_type <os_type>] [--multipath <multipath>]
<volume_id> <host_ip> <host_name> <initiator>
create volume iscsi target.
Positional arguments:
<volume_id> volume uuid
<host_ip> host ip ,which attach volume
<host_name> host name ,which attach volume
<initiator> host iscsi client,which attach volume
Optional arguments:
--platform <platform>
host architecture ,which attach volume.Default=x86_64
--do_local_attach <do_local_attach>
if or not attach volume.Default=false
--os_type <os_type> host operation system,whiic attach
volume.Default=linux2
--multipath <multipath>
if or not iscsi multipath.Default=false
[root@test ~]#
3)验证命令行
[root@test ~]# cinder --debug create-target a0ac29de-3a16-4b07-9aac-de63ccdf8fda 10.27.244.149 my03n010027244149.sncloud.com
iqn.1994-05.com.redhat:7329936b16d9 DEBUG:keystoneauth:REQ: curl -g -i -X POST http://10.27.241.34:8776/v2/d432ed8741cc427da398e4239f44deb4/volumes/a0ac29de-3a16-4b07-9aac-de63ccdf8fda/action -H "User-Agent: python-cinderclient" -H "Content-Type: application/json" -H "Accept: application/json" -H "X-Auth-Token: {SHA1}10e60c88cab7620ad3864cb1110d2b9c64a8170f" -d { "os-initialize_connection": { "connector": { "initiator": "iqn.1994-05.com.redhat:7329936b16d9", "ip": "10.27.244.149", "platform": "x86_64", "host": "my03n010027244149.sncloud.com", "do_local_attach": "false", "os_type": "linux2", "multipath": "false" } } } RESP BODY: { "connection_info": { "driver_volume_type": "iscsi", "data": { "target_luns": [0], "target_iqns": ["iqn.2010-10.org.openstack:volume-a0ac29de-3a16-4b07-9aac-de63ccdf8fda"], "auth_password": "24do7AqfnLDZ5DyB", "target_discovered": false, "encrypted": false, "qos_specs": null, "target_iqn": "iqn.2010-10.org.openstack:volume-a0ac29de-3a16-4b07-9aac-de63ccdf8fda", "target_portal": "10.27.244.144:3260", "volume_id": "a0ac29de-3a16-4b07-9aac-de63ccdf8fda", "target_lun": 0, "access_mode": "rw", "auth_username": "2y35wC68BsvU8M37tWCn", "auth_method": "CHAP", "target_portals": ["10.27.244.144:3260"] } } }