Njengoba kunikezwe lesi sigaba mayelana ne-kubernetes, siyini isendlalelo sokugcina se-Kubernetes control plane?
Context:I Kubernetes master node iphatha Kubernetes control plane of the cluster, iphatha umthwalo wayo wokusebenza futhi iqondisa ukuxhumana kulo lonke uhlelo. I Kubernetes control plane siqukethe izingxenye ezihlukahlukene, ngamunye inqubo yayo siqu, ukuthi ungagijima kokubili kwi-node eyodwa master noma on amakhosi amaningi ukusekela amaqoqo okusezingeni eliphezulu ukutholakala. Izingxenye ezahlukene ze Kubernetes control plane yilezi ezilandelayo:  I-etcd iyisitoreji sedatha esihlala njalo, esingasindi, esabiwe, esiyisihluthulelo-nesibalo esakhiwe yiCoreOS. Igcina idatha yokwakheka kwe-cluster ngokuthembekile, emele isimo esiphelele se-cluster nganoma yisiphi isikhathi esinikeziwe. I-etcd ithanda ukungaguquguquki ngaphezu kokutholakala uma kwenzeka ukwahlukaniswa kwenethiwekhi (bheka i-CAP theorem). Ukuvumelana kubalulekile ekuhleleni nasekusebenzeni kahle kwezinsizakalo. Iseva ye-API isebenza nge-Kubernetes API isebenzisa i-JSON nge-HTTP, enikeza kokubili isikhombimsebenzisi sangaphakathi nangaphandle ku-Kubernetes. Iseva ye-API icubungula futhi iqinisekise izicelo ze-REST futhi ivuselele isimo sezinto ze-API ku-etcd, ngaleyo ndlela ivumele amaklayenti ukuthi alungiselele imithwalo yomsebenzi neziqukathi kuwo wonke ama-node abasebenzi. Iseva ye-API isebenzisa i-watch API ye-etcd ukuqapha i-cluster, ukukhipha izinguquko ezibalulekile zokucushwa, noma ukubuyisela noma yikuphi ukuphambuka kwesimo se-cluster emuva kulokho okuchazwe ngumthuthukisi. Isibonelo, i-deployer ingacacisa ukuthi izibonelo ezintathu ze "pod" ethile (bheka ngezansi) zidinga ukusebenza. etcd igcina leli qiniso. Uma i-Deployment Controller ithola ukuthi kusebenza ama-instance amabili kuphela (angqubuzanayo nesimemezelo se-etcd), ihlela ukudala esinye isibonelo saleso sigaba. Umhleli uyingxenye enwetshekayo ekhetha ukuthi yiliphi i-node i-pod engahleliwe (inhlangano eyisisekelo ephethwe ngumhleli) esebenza kuyo, ngokuya ngokutholakala kwemithombo. I-scheduler ilandelela ukusetshenziswa kwezinsiza ku-node ngayinye ukuqinisekisa ukuthi umthwalo womsebenzi awuhlelekile ngaphezu kwezinsiza ezitholakalayo. Ngale njongo, umhleli kumele azi izidingo zemithombo, ukutholakala kwemithombo, kanye neminye imikhawulo enikezwe umsebenzisi noma imiyalo yenqubomgomo efana nekhwalithi yesevisi, ukuhlobana nezidingo zokulwa nokuhlobana, kanye nendawo yedatha. Indima yomhleli ukufanisa "ukunikezwa" kwemithombo nomthwalo womsebenzi "ukufunwa". Umlawuli uyinhlanganisela yokuvumelanisa eqondisa isimo sangempela se-cluster esimweni esifiselekayo, ukuxhumana neseva ye-API ukudala, ukuvuselela, nokususa izinsiza eziphethe (isb., ama-pods noma amaphuzu wokuphela kwensizakalo). Olunye uhlobo lwe-controller yi-Replication Controller, ephatha ukuphindaphinda nokukala ngokusebenza kwenani elithile lamakhophi e-pod kuyo yonke i-cluster. Iphinde iphathe ukudala ama-pods okufaka esikhundleni uma i-node eyisisekelo yehluleka. Ezinye izilawuli eziyingxenye yesistimu ye-Kubernetes eyinhloko zihlanganisa i-DaemonSet Controller yokusebenzisa i-pod eyodwa emshinini ngamunye (noma isethi encane yemishini), kanye ne-Job Controller yokusebenzisa ama-pod asebenza kuze kube sekugcineni (isibonelo, njengengxenye yomsebenzi we-batch). Amalebula abakhethi abayingxenye yencazelo yomlawuli acacisa isethi yama-pods alawulwa ngumlawuli. Umphathi wesilawuli inqubo ephatha isethi yezilawuli eziyinhloko zeKubernetes.
ETCD