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使用python语言调用原生接口(调用librados库来操作rados)
也就是下图中几种方式中的一种,就是图中的红色部分:下面是简单python代码示例:
#!/usr/bin/python#encoding=utf-8import rados, syscluster = rados.Rados(conffile='/etc/ceph/ceph.conf')#用当前的这个ceph的配置文件去创建一个rados,这里主要是解析ceph.conf中的 集群配置参数。然后将这些参数的值保存在rados中。cluster.connect()#这里将会创建一个radosclient的结构,这里会把这个结构主要包含了几个功能模块: 消息管理模块Messager,数据处理模块Objector,finisher线程模块。print "\n\nI/O Context and Object Operations"print "================================="print "\nCreating a context for the 'data' pool"if not cluster.pool_exists('data'): raise RuntimeError('No data pool exists')ioctx = cluster.open_ioctx('data')#为一个名字叫做data的存储池创建一个ioctx ,ioctx中会指明radosclient与Objector 模块,同时也会记录data的信息,包括pool的参数等。print "\nWriting object 'school' with contents 'hello , I are from chd university!' to pool 'data'."ioctx.write("school", "hello , I are from chd university!")ioctx.set_xattr("school", "lang", "en_US")print "\nWriting object 'name' with contents 'my name is lxl!' to pool 'data'."ioctx.write("name", "my name is lxl!")print "Writing XATTR 'lang' with value 'fr_FR' to object 'name'"ioctx.set_xattr("name", "lang", "fr_FR")print "\nContents of object 'school'\n------------------------"print ioctx.read("school")print ioctx.get_xattr("name", "lang")print "\nContents of object 'name'\n------------------------"print ioctx.read("name")print "\nClosing the connection."ioctx.close()
执行结果:
Python 示例代码2:
通过创建rbd块设备来操作rados,也就是下图中的红色部分:#!/usr/bin/env pythonimport sys,rados,rbddef connectceph(): cluster = rados.Rados(conffile = '/etc/ceph/ceph.conf') cluster.connect() ioctx = cluster.open_ioctx('rbd_test')#使用 rbd 之前,连接到 RADOS,并打开一个 IO context (和特定 pool 相关)#使用 rbd 之前,连接到 RADOS,并打开一个 IO context (和特定 pool 相关) rbd_inst = rbd.RBD() size = 40*1024**3 rbd_inst.create(ioctx,'test_image',size) image = rbd.Image(ioctx,'test_image') data = 'hello'* 300000 image.write(data,0) image.close() ioctx.close() cluster.shutdown()if __name__ == "__main__": connectceph()
解析:使用 rbd 之前,连接到 RADOS,并打开一个 IO context (和特定 pool 相关)
cluster = rados.Rados(conffile= ‘/etc/ceph/ceph.conf’) cluster.connect() ioctx = cluster.open_ioctx(‘rbd_test’)#初始化一个 RBD 对象
rbd_inst = rbd.RBD() size = 4 * 1024**3 # 4 GiB #创建 image rbd_inst.create(ioctx, ‘testimage’, size)#初始化 image 对象
image = rbd.Image(ioctx, ‘testimage’) #准备 约14M字符的数据 data = ‘hello world !!’* 1024**2 #写入数据 image.write(data, 0)#关闭 image 对象
image.close() #关闭 IO Context ioctx.close() #关闭连接 cluster.shutdown()可以看看执行结果:
Python示例代码3:
窗体顶端 在给定的集群上发出ceph命令并提供返回的json#!/usr/bin/env python# -*- coding: UTF-8 -*-import jsonfrom rados import Radosfrom rados import Error as RadosErrorclass CephClusterCommand(dict): """ Issue a ceph command on the given cluster and provide the returned json """ def __init__(self, cluster, **kwargs): dict.__init__(self) ret, buf, err = cluster.mon_command(json.dumps(kwargs), '', timeout=5) if ret != 0: self['err'] = err else: self.update(json.loads(buf))config={ 'conffile': '/etc/ceph/ceph.conf', 'conf': {}}with Rados(**config) as cluster: cluster_status = CephClusterCommand(cluster, prefix='status', format='json') print cluster_status
执行结果:
{u’election_epoch’: 4, u’quorum’: [0], u’monmap’: {u’epoch’: 1, u’mons’: [{u’name’: u’node1’, u’rank’: 0, u’addr’: u’192.168.1.220:6789/0’}], u’modified’: u’2017-11-27 10:57:00.018670’, u’fsid’: u’f2891898-aa3b-4bce-8bf1-668b8cf5b45a’, u’created’: u’2017-11-27 10:57:00.018670’}, u’health’: {u’detail’: [], u’timechecks’: {u’round_status’: u’finished’, u’epoch’: 4, u’round’: 0}, u’health’: {u’health_services’: [{u’mons’: [{u’last_updated’: u’2018-03-02 09:41:42.153833’, u’name’: u’node1’, u’avail_percent’: 89, u’kb_total’: 28797196, u’kb_avail’: 25738680, u’health’: u’HEALTH_OK’, u’kb_used’: 3058516, u’store_stats’: {u’bytes_total’: 15344382, u’bytes_log’: 2031616, u’last_updated’: u’0.000000’, u’bytes_misc’: 2031632, u’bytes_sst’: 11281134}}]}]}, u’overall_status’: u’HEALTH_WARN’, u’summary’: [{u’severity’: u’HEALTH_WARN’, u’summary’: u’too many PGs per OSD (428 > max 300)’}]}, u’fsid’: u’f2891898-aa3b-4bce-8bf1-668b8cf5b45a’, u’quorum_names’: [u’node1’], u’fsmap’: {u’up:standby’: 1, u’by_rank’: [{u’status’: u’up:active’, u’filesystem_id’: 1, u’name’: u’node2’, u’rank’: 0}], u’max’: 1, u’up’: 1, u’epoch’: 6, u’in’: 1, u’id’: 1}, u’osdmap’: {u’osdmap’: {u’full’: False, u’nearfull’: False, u’num_osds’: 2, u’num_up_osds’: 2, u’epoch’: 36, u’num_in_osds’: 2, u’num_remapped_pgs’: 0}}, u’pgmap’: {u’bytes_total’: 58976657408, u’num_pgs’: 428, u’data_bytes’: 143101344, u’bytes_used’: 17297178624, u’version’: 165507, u’pgs_by_state’: [{u’count’: 428, u’state_name’: u’active+clean’}], u’bytes_avail’: 41679478784}}