還是有許多地方可能錯了 希望大嬸們 看見 給予意見 ！

這個檔案位於\nova\virt，是一個底層的driver.py,原始碼如下（和以前一樣添加了些註釋，另外把我 覺得比較重要的computerDriver類列出來 了，並將下面的每個函式分離 加以註釋《見下面圖片》！我看見後面好多函式都是繼承的ComputerDriver比如nova\virt\libvirt下面的connection.py裡面的class LibvirtConnection(driver.ComputeDriver):）：

1. """
2. Driverbase-classes:
4. (Beginningof)thecontractthatcomputedriversmustfollow,andshared
5. typesthatsupportthatcontract
6. """
8. fromnova.computeimportpower_state
11. classInstanceInfo(object):
12. def__init__(self,name,state):
13. self.name=name
14. assertstateinpower_state.valid_states(),"Badstate:%s"%state
15. self.state=state
18. defblock_device_info_get_root(block_device_info):
19. block_device_info=block_device_info
    or{}
20. returnblock_device_info.get('root_device_name')
23. defblock_device_info_get_swap(block_device_info):
24. block_device_info=block_device_infoor{}
25. returnblock_device_info.get('swap')or{'device_name':None,
26. 'swap_size':0}
29. defswap_is_usable(swap):
30. returnswapandswap['device_name']andswap['swap_size']>0
33. defblock_device_info_get_ephemerals(block_device_info):
34. block_device_info=block_device_infoor{}
35. ephemerals=block_device_info.get('ephemerals')or[]
36. returnephemerals
39. defblock_device_info_get_mapping(block_device_info):
40. block_device_info=block_device_infoor{}
41. block_device_mapping=block_device_info.get('block_device_mapping')or[]
42. returnblock_device_mapping
45. classComputeDriver(object):
46. """Baseclassforcomputedrivers.
48. Theinterfacetothisclasstalksintermsof'instances'(AmazonEC2and
49. internalNovaterminology),bywhichwemean'runningvirtualmachine'
50. (XenAPIterminology)ordomain(Xenorlibvirtterminology).
52. AninstancehasanID,whichistheidentifierchosenbyNovatorepresent
53. theinstancefurtherupthestack.Thisisunfortunatelyalsocalleda
54. 'name'elsewhere.Asfarasthislayerisconcerned,'instanceID'and
55. 'instancename'aresynonyms.
57. NotethattheinstanceIDornameisnothuman-readableor
58. customer-controlled--it'saninternalIDchosenbyNova.Atthe
59. nova.virtlayer,instancesdonothavehuman-readablenamesatall--such
60. thingsareonlyknownhigherupthestack.
62. Mostvirtualizationplatformswillalsohavetheirownidentityschemes,
63. touniquelyidentifyaVMordomain.TheseIDsmuststayinternaltothe
64. platform-specificlayer,andneverescapetheconnectioninterface.The
65. platform-specificlayerisresponsibleforkeepingtrackofwhichinstance
66. IDmapstowhichplatform-specificID,andviceversa.
68. Incontrast,thelist_disksandlist_interfacescallsmayreturn
69. platform-specificIDs.Theseidentifyaspecificvirtualdiskorspecific
70. virtualnetworkinterface,andtheseIDsareopaquetotherestofNova.
72. Somemethodsheretakeaninstanceofnova.compute.service.Instance.This
73. isthedatastructureusedbynova.computetostoredetailsregardingan
74. instance,andpassthemintothislayer.Thislayerisresponsiblefor
75. translatingthatgenericdatastructureintotermsthatarespecifictothe
76. virtualizationplatform.
78. """
79. #此處為了讓大家看的明白將ComputerDriver的類圖列出來
81. definit_host(self,host):
82. """Initializeanythingthatisnecessaryforthedrivertofunction,
83. includingcatchingupwithcurrentlyrunningVM'sonthegivenhost."""
84. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
85. raiseNotImplementedError()
87. defget_info(self,instance_name):
88. """Getthecurrentstatusofaninstance,byname(notID!)
90. Returnsadictcontaining:
92. :state:therunningstate,oneofthepower_statecodes
93. :max_mem:(int)themaximummemoryinKBytesallowed
94. :mem:(int)thememoryinKBytesusedbythedomain
95. :num_cpu:(int)thenumberofvirtualCPUsforthedomain
96. :cpu_time:(int)theCPUtimeusedinnanoseconds
97. """
98. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
99. raiseNotImplementedError()
101. deflist_instances(self):
102. """
103. Returnthenamesofalltheinstancesknowntothevirtualization
104. layer,asalist.
105. """
106. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
107. raiseNotImplementedError()
109. deflist_instances_detail(self):
110. """ReturnalistofInstanceInfoforallregisteredVMs"""
111. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
112. raiseNotImplementedError()
114. defspawn(self,context,instance,
115. network_info=None,block_device_info=None):
116. """
117. Createanewinstance/VM/domainonthevirtualizationplatform.
119. Oncethissuccessfullycompletes,theinstanceshouldbe
120. running(power_state.RUNNING).
122. Ifthisfails,anypartialinstanceshouldbecompletely
123. cleanedup,andthevirtualizationplatformshouldbeinthestate
124. thatitwasbeforethiscallbegan.
126. :paramcontext:securitycontext
127. :paraminstance:InstanceobjectasreturnedbyDBlayer.
128. Thisfunctionshouldusethedatatheretoguide
129. thecreationofthenewinstance.
130. :paramnetwork_info:
131. :py:meth:`~nova.network.manager.NetworkManager.get_instance_nw_info`
132. :paramblock_device_info:
133. """
134. raiseNotImplementedError()
136. defdestroy(self,instance,network_info,cleanup=True):
137. """Destroy(shutdownanddelete)thespecifiedinstance.
139. Iftheinstanceisnotfound(forexampleifnetworkingfailed),this
140. functionshouldstillsucceed.It'sprobablyagoodideatologa
141. warninginthatcase.
143. :paraminstance:InstanceobjectasreturnedbyDBlayer.
144. :paramnetwork_info:
145. :py:meth:`~nova.network.manager.NetworkManager.get_instance_nw_info`
146. :paramcleanup:
148. """
149. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
150. raiseNotImplementedError()
152. defreboot(self,instance,network_info):
153. """Rebootthespecifiedinstance.
155. :paraminstance:InstanceobjectasreturnedbyDBlayer.
156. :paramnetwork_info:
157. :py:meth:`~nova.network.manager.NetworkManager.get_instance_nw_info`
158. """
159. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
160. raiseNotImplementedError()
162. defsnapshot_instance(self,context,instance_id,p_w_picpath_id):
163. raiseNotImplementedError()
165. defget_console_pool_info(self,console_type):
166. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
167. raiseNotImplementedError()
169. defget_console_output(self,instance):
170. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
171. raiseNotImplementedError()
173. defget_ajax_console(self,instance):
174. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
175. raiseNotImplementedError()
177. defget_diagnostics(self,instance):
178. """ReturndataaboutVMdiagnostics"""
179. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
180. raiseNotImplementedError()
182. defget_host_ip_addr(self):
183. """
184. RetrievestheIPaddressofthedom0
185. """
186. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
187. raiseNotImplementedError()
189. defattach_volume(self,context,instance_id,volume_id,mountpoint):
190. """Attachthediskatdevice_pathtotheinstanceatmountpoint"""
191. raiseNotImplementedError()
193. defdetach_volume(self,context,instance_id,volume_id):
194. """Detachthediskattachedtotheinstanceatmountpoint"""
195. raiseNotImplementedError()
197. defcompare_cpu(self,cpu_info):
198. """Comparesgivencpuinfoagainsthost確保vm能執行
200. BeforeattemptingtomigrateaVMtothishost,
201. compare_cpuiscalledtoensurethattheVMwill
202. actuallyrunhere.
204. :paramcpu_info:(str)JSONstructuredescribingthesourceCPU.
205. :returns:Noneifmigrationisacceptable
206. :raises::py:class:`~nova.exception.InvalidCPUInfo`ifmigration
207. isnotacceptable.
208. """
209. raiseNotImplementedError()
211. defmigrate_disk_and_power_off(self,instance,dest):
212. """
213. Transfersthediskofarunninginstanceinmultiplephases,turning
214. offtheinstancebeforetheend.
215. """
216. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
217. raiseNotImplementedError()
219. defsnapshot(self,context,instance,p_w_picpath_id):
220. """
221. Snapshotsthespecifiedinstance.
223. :paramcontext:securitycontext
224. :paraminstance:InstanceobjectasreturnedbyDBlayer.
225. :paramp_w_picpath_id:Referencetoapre-createdp_w_picpaththatwill
226. holdthesnapshot.
227. """
228. raiseNotImplementedError()
230. deffinish_migration(self,context,instance,disk_info,network_info,
231. resize_instance):
232. #開啟一個遷移的例項，完成一個調整
233. """Completesaresize,turningonthemigratedinstance
235. :paramnetwork_info:
236. :py:meth:`~nova.network.manager.NetworkManager.get_instance_nw_info`
237. """
238. raiseNotImplementedError()
240. defrevert_migration(self,instance):
241. #返回一個調整，推動回到例項？
242. """Revertsaresize,poweringbackontheinstance"""
243. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
244. raiseNotImplementedError()
246. defpause(self,instance,callback):
247. """Pausethespecifiedinstance."""
248. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
249. raiseNotImplementedError()
251. defunpause(self,instance,callback):
252. """UnpausepausedVMinstance"""
253. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
254. raiseNotImplementedError()
256. defsuspend(self,instance,callback):
257. #掛起指定的例項
258. """suspendthespecifiedinstance"""
259. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
260. raiseNotImplementedError()
262. defresume(self,instance,callback):
263. """resumethespecifiedinstance"""
264. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
265. raiseNotImplementedError()
267. defrescue(self,context,instance,callback,network_info):
268. #恢復指定的例項
269. """Rescuethespecifiedinstance"""
270. raiseNotImplementedError()
272. defunrescue(self,instance,callback,network_info):
273. """Unrescuethespecifiedinstance"""
274. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
275. raiseNotImplementedError()
277. defupdate_available_resource(self,ctxt,host):
278. #在computeNode表中更新電腦資源管理的資訊
279. """UpdatescomputemanagerresourceinfoonComputeNodetable.
281. Thismethodiscalledwhennova-computelaunches,and
282. wheneveradminexecutes"nova-manageserviceupdate_resource".
284. :paramctxt:securitycontext
285. :paramhost:hostnamethatcomputemanageriscurrentlyrunning
287. """
288. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
289. raiseNotImplementedError()
291. deflive_migration(self,ctxt,instance_ref,dest,
292. post_method,recover_method):
293. #分發處理高負荷，當有高負荷操作時候，大量生成live_mirgration
294. """Spawninglive_migrationoperationfordistributinghigh-load.
296. :paramctxt:securitycontext
297. :paraminstance_ref:
298. nova.db.sqlalchemy.models.Instanceobject
299. instanceobjectthatismigrated.
300. :paramdest:destinationhost
301. :parampost_method:
302. postoperationmethod.
303. expectednova.compute.manager.post_live_migration.
304. :paramrecover_method:
305. recoverymethodwhenanyexceptionoccurs.
306. expectednova.compute.manager.recover_live_migration.
308. """
309. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
310. raiseNotImplementedError()
312. defrefresh_security_group_rules(self,security_group_id):
313. #改變安全組之後呼叫
314. """Thismethodiscalledafterachangetosecuritygroups.
316. Allsecuritygroupsandtheirassociatedrulesliveinthedatastore,
317. andcallingthismethodshouldapplytheupdatedrulestoinstances
318. runningthespecifiedsecuritygroup.
320. Anerrorshouldberaisediftheoperationcannotcomplete.
322. """
323. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
324. raiseNotImplementedError()
326. defrefresh_security_group_members(self,security_group_id):
327. #當一個安全組被新增到一個例項，這個方法被呼叫
328. """Thismethodiscalledwhenasecuritygroupisaddedtoaninstance.
330. Thismessageissenttothevirtualizationdriversonhoststhatare
331. runninganinstancethatbelongstoasecuritygroupthathasarule
332. thatreferencesthesecuritygroupidentifiedby`security_group_id`.
333. Itistheresponsiblityofthismethodtomakesureanyrules
334. thatauthorizetrafficflowwithmembersofthesecuritygroupare
335. updatedandanynewmemberscancommunicate,andanyremovedmembers
336. cannot.
338. Scenario:
339. *wearerunningonhost'H0'andwehaveaninstance'i-0'.
340. *instance'i-0'isamemberofsecuritygroup'speaks-b'
341. *group'speaks-b'hasaningressrulethatauthorizesgroup'b'
342. *anotherhost'H1'runsaninstance'i-1'
343. *instance'i-1'isamemberofsecuritygroup'b'
345. When'i-1'launchesorterminateswewillrecievethemessage
346. toupdatemembersofgroup'b',atwhichtimewewillmake
347. anychangesneededtotherulesforinstance'i-0'toallow
348. ordenytrafficcomingfrom'i-1',dependingonifitisbeing
349. addedorremovedfromthegroup.
351. Inthisscenario,'i-1'couldjustaseasilyhavebeenrunningonour
352. host'H0'andthismethodwouldstillhavebeencalled.Thepointwas
353. thatthismethodisn'tcalledonthehostwhereinstancesofthat
354. grouparerunning(asisthecasewith
355. :method:`refresh_security_group_rules`)butiscalledwherereferences
356. aremadetoauthorizingthoseinstances.
358. Anerrorshouldberaisediftheoperationcannotcomplete.
360. """
361. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
362. raiseNotImplementedError()
364. defrefresh_provider_fw_rules(self,security_group_id):
365. #這觸發一個基於資料庫改變的防火牆的更新
366. """Thistriggersafirewallupdatebasedondatabasechanges.
368. Whenthisiscalled,ruleshaveeitherbeenaddedorremovedfromthe
369. datastore.Youcanretrieveruleswith
370. :method:`nova.db.api.provider_fw_rule_get_all`.
372. Providerrulestakeprecedenceoversecuritygrouprules.IfanIP
373. wouldbeallowedbyasecuritygroupingressrule,butblockedby
374. aproviderrule,thenpacketsfromtheIParedropped.Thisincludes
375. intra-projecttrafficinthecaseoftheallow_project_net_traffic
376. flagforthelibvirt-derivedclasses.
378. """
379. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
380. raiseNotImplementedError()
382. defreset_network(self,instance):
383. """resetnetworkingforspecifiedinstance"""
384. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
385. pass
387. defensure_filtering_rules_for_instance(self,instance_ref,network_info):
388. #設定過濾規則,並等待它完成
389. """Settingupfilteringrulesandwaitingforitscompletion.
391. Tomigrateaninstance,filteringrulestohypervisors
392. andfirewallsareinevitableondestinationhost.
393. (Waitingonlyforfilteringrulestohypervisor,
394. sincefilteringrulestofirewallrulescanbesetfaster).
396. Concretely,thebelowmethodmustbecalled.
397. -setup_basic_filtering(fornova-basic,etc.)
398. -prepare_instance_filter(fornova-instance-instance-xxx,etc.)
400. to_xmlmayhavetobecalledsinceitdefinesPROJNET,PROJMASK.
401. butlibvirtmigratesthosevaluethroughmigrateToURI(),
402. so,noneedtobecalled.
404. Don'tusethreadforthismethodsincemigrationshould
405. notbestartedwhensetting-upfilteringrulesoperations
406. arenotcompleted.
408. :paramsinstance_ref:nova.db.sqlalchemy.models.Instanceobject
410. """
411. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
412. raiseNotImplementedError()
414. defunfilter_instance(self,instance,network_info):
415. """Stopfilteringinstance"""
416. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
417. raiseNotImplementedError()
419. defset_admin_password(self,context,instance_id,new_pass=None):
420. """
421. Settherootpasswordonthespecifiedinstance.
423. Thefirstparameterisaninstanceofnova.compute.service.Instance,
424. andsotheinstanceisbeingspecifiedasinstance.name.Thesecond
425. parameteristhevalueofthenewpassword.
426. """
427. raiseNotImplementedError()
429. definject_file(self,instance,b64_path,b64_contents):
430. """在指定的例項上寫檔案
431. Writesafileonthespecifiedinstance.
433. Thefirstparameterisaninstanceofnova.compute.service.Instance,
434. andsotheinstanceisbeingspecifiedasinstance.name.Thesecond
435. parameteristhebase64-encodedpathtowhichthefileistobe
436. writtenontheinstance;thethirdisthecontentsofthefile,also
437. base64-encoded.
438. """
439. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
440. raiseNotImplementedError()
442. defagent_update(self,instance,url,md5hash):
443. #在指定的例項中更新代理
444. """
445. Updateagentonthespecifiedinstance.
447. Thefirstparameterisaninstanceofnova.compute.service.Instance,
448. andsotheinstanceisbeingspecifiedasinstance.name.Thesecond
449. parameteristheURLoftheagenttobefetchedandupdatedonthe
450. instance;thethirdisthemd5hashofthefileforverification
451. purposes.
452. """
453. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
454. raiseNotImplementedError()
456. definject_network_info(self,instance,nw_info):
457. #為指定的例項注入網路資訊
458. """injectnetworkinfoforspecifiedinstance"""
459. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
460. pass
462. defpoll_rescued_instances(self,timeout):
463. #輪詢已經恢復的例項
464. """Pollforrescuedinstances"""
465. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
466. raiseNotImplementedError()
468. defhost_power_action(self,host,action):
469. """Reboots,shutsdownorpowersupthehost."""
470. raiseNotImplementedError()
472. defset_host_enabled(self,host,enabled):
473. #設定指定的主機有能力接受新的例項
474. """Setsthespecifiedhost'sabilitytoacceptnewinstances."""
475. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
476. raiseNotImplementedError()
478. defplug_vifs(self,instance,network_info):
479. """PlugsinVIFstonetworks."""
480. #TODO(Vek):Needtopasscontextinforaccesstoauth_token
481. raiseNotImplementedError()
483. defupdate_host_status(self):
484. """Refreshhoststats"""
485. raiseNotImplementedError()
487. defget_host_stats(self,refresh=False):
488. """Returncurrentlyknownhoststats"""
489. raiseNotImplementedError()
491. deflist_disks(self,instance_name):
492. """
493. ReturntheIDsofallthevirtualdisksattachedtothespecified
494. instance,asalist.TheseIDsareopaquetothecaller(theyare
495. onlyusefulforgivingbacktothislayerasaparameterto
496. disk_stats).TheseIDsonlyneedtobeuniqueforagiveninstance.
498. NotethatthisfunctiontakesaninstanceID.
499. """
500. raiseNotImplementedError()
502. deflist_interfaces(self,instance_name):
503. """
504. ReturntheIDsofallthevirtualnetworkinterfacesattachedtothe
505. specifiedinstance,asalist.TheseIDsareopaquetothecaller
506. (theyareonlyusefulforgivingbacktothislayerasaparameterto
507. interface_stats).TheseIDsonlyneedtobeuniqueforagiven
508. instance.
510. NotethatthisfunctiontakesaninstanceID.
511. """
512. raiseNotImplementedError()
514. defresize(self,instance,flavor):
515. """
516. Resizes/Migratesthespecifiedinstance.
518. TheflavorparameterdetermineswhetherornottheinstanceRAMand
519. diskspacearemodified,andifso,towhatsize.
520. """
521. raiseNotImplementedError()
523. defblock_stats(self,instance_name,disk_id):
524. """
525. Returnperformancecountersassociatedwiththegivendisk_idonthe
526. giveninstance_name.Thesearereturnedas[rd_req,rd_bytes,wr_req,
527. wr_bytes,errs],whererdindicatesread,wrindicateswrite,reqis
528. thetotalnumberofI/Orequestsmade,bytesisthetotalnumberof
529. bytestransferred,anderrsisthenumberofrequestsheldupduetoa
530. fullpipeline.
532. Allcountersarelongintegers.
534. Thismethodisoptional.Onsomeplatforms(e.g.XenAPI)performance
535. statisticscanberetrieveddirectlyinaggregateform,withoutNova
536. havingtodotheaggregation.Onthoseplatforms,thismethodis
537. unused.
539. NotethatthisfunctiontakesaninstanceID.
540. """
541. raiseNotImplementedError()
543. definterface_stats(self,instance_name,iface_id):
544. """
545. Returnperformancecountersassociatedwiththegiveniface_idonthe
546. giveninstance_id.Thesearereturnedas[rx_bytes,rx_packets,
547. rx_errs,rx_drop,tx_bytes,tx_packets,tx_errs,tx_drop],whererx
548. indicatesreceive,txindicatestransmit,bytesandpacketsindicate
549. thetotalnum

550. berofbytesorpacketstransferred,anderrsanddropped
551. isthetotalnumberofpacketsfailed/dropped.
553. Allcountersarelongintegers.
555. Thismethodisoptional.Onsomeplatforms(e.g.XenAPI)performance
556. statisticscanberetrieveddirectlyinaggregateform,withoutNova
557. havingtodotheaggregation.Onthoseplatforms,thismethodis
558. unused.
560. NotethatthisfunctiontakesaninstanceID.
561. """
562. raiseNotImplementedError()

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轉載於:https://blog.51cto.com/brucemars/967409