• 使用etcdctl访问kuberentes数据
    • etcd中kubernetes的元数据
    • 参考

    使用etcdctl访问kuberentes数据

    Kubenretes1.6中使用etcd V3版本的API，使用etcdctl直接ls的话只能看到/kube-centos一个路径。需要在命令前加上ETCDCTL_API=3这个环境变量才能看到kuberentes在etcd中保存的数据。

    1. ETCDCTL_API=3 etcdctl get /registry/namespaces/default -w=json|python -m json.tool
    • -w指定输出格式

    将得到这样的json的结果：

    1. {
    2.     "count": 1,
    3.     "header": {
    4.         "cluster_id": 12091028579527406772,
    5.         "member_id": 16557816780141026208,
    6.         "raft_term": 36,
    7.         "revision": 29253467
    8.     },
    9.     "kvs": [
    10.         {
    11.             "create_revision": 5,
    12.             "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMvZGVmYXVsdA==",
    13.             "mod_revision": 5,
    14.             "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmIKSAoHZGVmYXVsdBIAGgAiACokZTU2YzMzMDgtMWVhOC0xMWU3LThjZDctZjRlOWQ0OWY4ZWQwMgA4AEILCIn4sscFEKOg9xd6ABIMCgprdWJlcm5ldGVzGggKBkFjdGl2ZRoAIgA=",
    15.             "version": 1
    16.         }
    17.     ]
    18. }

    使用--prefix可以看到所有的子目录，如查看集群中的namespace：

    1. ETCDCTL_API=3 etcdctl get /registry/namespaces --prefix -w=json|python -m json.tool

    输出结果中可以看到所有的namespace。

    1. {
    2.     "count": 8,
    3.     "header": {
    4.         "cluster_id": 12091028579527406772,
    5.         "member_id": 16557816780141026208,
    6.         "raft_term": 36,
    7.         "revision": 29253722
    8.     },
    9.     "kvs": [
    10.         {
    11.             "create_revision": 24310883,
    12.             "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMvYXV0b21vZGVs",
    13.             "mod_revision": 24310883,
    14.             "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmQKSgoJYXV0b21vZGVsEgAaACIAKiQ1MjczOTU1ZC1iMzEyLTExZTctOTcwYy1mNGU5ZDQ5ZjhlZDAyADgAQgsI7fSWzwUQ6Jv1Z3oAEgwKCmt1YmVybmV0ZXMaCAoGQWN0aXZlGgAiAA==",
    15.             "version": 1
    16.         },
    17.         {
    18.             "create_revision": 21387676,
    19.             "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMvYnJhbmQ=",
    20.             "mod_revision": 21387676,
    21.             "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmEKRwoFYnJhbmQSABoAIgAqJGNkZmQ1Y2NmLWExYzktMTFlNy05NzBjLWY0ZTlkNDlmOGVkMDIAOABCDAjR9qLOBRDYn83XAXoAEgwKCmt1YmVybmV0ZXMaCAoGQWN0aXZlGgAiAA==",
    22.             "version": 1
    23.         },
    24.         {
    25.             "create_revision": 5,
    26.             "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMvZGVmYXVsdA==",
    27.             "mod_revision": 5,
    28.             "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmIKSAoHZGVmYXVsdBIAGgAiACokZTU2YzMzMDgtMWVhOC0xMWU3LThjZDctZjRlOWQ0OWY4ZWQwMgA4AEILCIn4sscFEKOg9xd6ABIMCgprdWJlcm5ldGVzGggKBkFjdGl2ZRoAIgA=",
    29.             "version": 1
    30.         },
    31.         {
    32.             "create_revision": 18504694,
    33.             "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMvZGV2",
    34.             "mod_revision": 24310213,
    35.             "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmwKUgoDZGV2EgAaACIAKiQyOGRlMGVjNS04ZTEzLTExZTctOTcwYy1mNGU5ZDQ5ZjhlZDAyADgAQgwI89CezQUQ0v2fuQNaCwoEbmFtZRIDZGV2egASDAoKa3ViZXJuZXRlcxoICgZBY3RpdmUaACIA",
    36.             "version": 4
    37.         },
    38.         {
    39.             "create_revision": 10,
    40.             "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMva3ViZS1wdWJsaWM=",
    41.             "mod_revision": 10,
    42.             "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmcKTQoLa3ViZS1wdWJsaWMSABoAIgAqJGU1ZjhkY2I1LTFlYTgtMTFlNy04Y2Q3LWY0ZTlkNDlmOGVkMDIAOABCDAiJ+LLHBRDdrsDPA3oAEgwKCmt1YmVybmV0ZXMaCAoGQWN0aXZlGgAiAA==",
    43.             "version": 1
    44.         },
    45.         {
    46.             "create_revision": 2,
    47.             "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMva3ViZS1zeXN0ZW0=",
    48.             "mod_revision": 2,
    49.             "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmYKTAoLa3ViZS1zeXN0ZW0SABoAIgAqJGU1NmFhMDVkLTFlYTgtMTFlNy04Y2Q3LWY0ZTlkNDlmOGVkMDIAOABCCwiJ+LLHBRDoq9ASegASDAoKa3ViZXJuZXRlcxoICgZBY3RpdmUaACIA",
    50.             "version": 1
    51.         },
    52.         {
    53.             "create_revision": 3774247,
    54.             "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMvc3BhcmstY2x1c3Rlcg==",
    55.             "mod_revision": 3774247,
    56.             "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEoABCmYKDXNwYXJrLWNsdXN0ZXISABoAIgAqJDMyNjY3ZDVjLTM0YWMtMTFlNy1iZmJkLThhZjFlM2E3YzViZDIAOABCDAiA1cbIBRDU3YuAAVoVCgRuYW1lEg1zcGFyay1jbHVzdGVyegASDAoKa3ViZXJuZXRlcxoICgZBY3RpdmUaACIA",
    57.             "version": 1
    58.         },
    59.         {
    60.             "create_revision": 15212191,
    61.             "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMveWFybi1jbHVzdGVy",
    62.             "mod_revision": 15212191,
    63.             "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEn0KYwoMeWFybi1jbHVzdGVyEgAaACIAKiQ2YWNhNjk1Yi03N2Y5LTExZTctYmZiZC04YWYxZTNhN2M1YmQyADgAQgsI1qiKzAUQkoqxDloUCgRuYW1lEgx5YXJuLWNsdXN0ZXJ6ABIMCgprdWJlcm5ldGVzGggKBkFjdGl2ZRoAIgA=",
    64.             "version": 1
    65.         }
    66.     ]
    67. }

    key的值是经过base64编码，需要解码后才能看到实际值，如：

    1. $ echo L3JlZ2lzdHJ5L25hbWVzcGFjZXMvYXV0b21vZGVs|base64 -d
    2. /registry/namespaces/automodel

    etcd中kubernetes的元数据

    我们使用kubectl命令获取的kubernetes的对象状态实际上是保存在etcd中的，使用下面的脚本可以获取etcd中的所有kubernetes对象的key：

    注意，我们使用了ETCD v3版本的客户端命令来访问etcd。

    1. #!/bin/bash
    2. # Get kubernetes keys from etcd
    3. export ETCDCTL_API=3
    4. keys=`etcdctl get /registry --prefix -w json|python -m json.tool|grep key|cut -d ":" -f2|tr -d '"'|tr -d ","`
    5. for x in $keys;do
    6.   echo $x|base64 -d|sort
    7. done

    通过输出的结果我们可以看到kubernetes的原数据是按何种结构包括在kuberentes中的，输出结果如下所示：

    1. /registry/ThirdPartyResourceData/istio.io/istioconfigs/default/route-rule-details-default
    2. /registry/ThirdPartyResourceData/istio.io/istioconfigs/default/route-rule-productpage-default
    3. /registry/ThirdPartyResourceData/istio.io/istioconfigs/default/route-rule-ratings-default
    4. ...
    5. /registry/configmaps/default/namerctl-script
    6. /registry/configmaps/default/namerd-config
    7. /registry/configmaps/default/nginx-config
    8. ...
    9. /registry/deployments/default/sdmk-page-sdmk
    10. /registry/deployments/default/sdmk-payment-web
    11. /registry/deployments/default/sdmk-report
    12. ...

    我们可以看到所有的Kuberentes的所有元数据都保存在/registry目录下，下一层就是API对象类型（复数形式），再下一层是namespace，最后一层是对象的名字。

    以下是etcd中存储的kubernetes所有的元数据类型：

    1. ThirdPartyResourceData
    2. apiextensions.k8s.io
    3. apiregistration.k8s.io
    4. certificatesigningrequests
    5. clusterrolebindings
    6. clusterroles
    7. configmaps
    8. controllerrevisions
    9. controllers
    10. daemonsets
    11. deployments
    12. events
    13. horizontalpodautoscalers
    14. ingress
    15. limitranges
    16. minions
    17. monitoring.coreos.com
    18. namespaces
    19. persistentvolumeclaims
    20. persistentvolumes
    21. poddisruptionbudgets
    22. pods
    23. ranges
    24. replicasets
    25. resourcequotas
    26. rolebindings
    27. roles
    28. secrets
    29. serviceaccounts
    30. services
    31. statefulsets
    32. storageclasses
    33. thirdpartyresources

    参考

    • etcd中文文档
    • etcd官方文档