使用etcdctl访问kubernetes数据

如果是使用 kubeadm 创建的集群，在 Kubenretes 1.11 中，etcd 默认使用 tls ，这时你可以在 master 节点上使用以下命令来访问 etcd ：

ETCDCTL_API=3 etcdctl --cacert=/etc/kubernetes/pki/etcd/ca.crt \
--cert=/etc/kubernetes/pki/etcd/peer.crt \
--key=/etc/kubernetes/pki/etcd/peer.key \
get /registry/namespaces/default -w=json | jq .

-w指定输出格式

将得到这样的json的结果：

{
    "count": 1,
    "header": {
        "cluster_id": 12091028579527406772,
        "member_id": 16557816780141026208,
        "raft_term": 36,
        "revision": 29253467
    },
    "kvs": [
        {
            "create_revision": 5,
            "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMvZGVmYXVsdA==",
            "mod_revision": 5,
            "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmIKSAoHZGVmYXVsdBIAGgAiACokZTU2YzMzMDgtMWVhOC0xMWU3LThjZDctZjRlOWQ0OWY4ZWQwMgA4AEILCIn4sscFEKOg9xd6ABIMCgprdWJlcm5ldGVzGggKBkFjdGl2ZRoAIgA=",
            "version": 1
        }
    ]
}

输出结果中可以看到所有的namespace。

{
    "count": 8,
    "header": {
        "cluster_id": 12091028579527406772,
        "member_id": 16557816780141026208,
        "raft_term": 36,
        "revision": 29253722
    },
    "kvs": [
        {
            "create_revision": 24310883,
            "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMvYXV0b21vZGVs",
            "mod_revision": 24310883,
            "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmQKSgoJYXV0b21vZGVsEgAaACIAKiQ1MjczOTU1ZC1iMzEyLTExZTctOTcwYy1mNGU5ZDQ5ZjhlZDAyADgAQgsI7fSWzwUQ6Jv1Z3oAEgwKCmt1YmVybmV0ZXMaCAoGQWN0aXZlGgAiAA==",
            "version": 1
        },
        {
            "create_revision": 21387676,
            "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMvYnJhbmQ=",
            "mod_revision": 21387676,
        },
        {
            "create_revision": 5,
            "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMvZGVmYXVsdA==",
            "mod_revision": 5,
            "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmIKSAoHZGVmYXVsdBIAGgAiACokZTU2YzMzMDgtMWVhOC0xMWU3LThjZDctZjRlOWQ0OWY4ZWQwMgA4AEILCIn4sscFEKOg9xd6ABIMCgprdWJlcm5ldGVzGggKBkFjdGl2ZRoAIgA=",
            "version": 1
        },
        {
            "create_revision": 18504694,
            "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMvZGV2",
            "mod_revision": 24310213,
            "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmwKUgoDZGV2EgAaACIAKiQyOGRlMGVjNS04ZTEzLTExZTctOTcwYy1mNGU5ZDQ5ZjhlZDAyADgAQgwI89CezQUQ0v2fuQNaCwoEbmFtZRIDZGV2egASDAoKa3ViZXJuZXRlcxoICgZBY3RpdmUaACIA",
            "version": 4
        },
        {
            "create_revision": 10,
            "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMva3ViZS1wdWJsaWM=",
            "mod_revision": 10,
            "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmcKTQoLa3ViZS1wdWJsaWMSABoAIgAqJGU1ZjhkY2I1LTFlYTgtMTFlNy04Y2Q3LWY0ZTlkNDlmOGVkMDIAOABCDAiJ+LLHBRDdrsDPA3oAEgwKCmt1YmVybmV0ZXMaCAoGQWN0aXZlGgAiAA==",
            "version": 1
        },
        {
            "create_revision": 2,
            "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMva3ViZS1zeXN0ZW0=",
            "mod_revision": 2,
            "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmYKTAoLa3ViZS1zeXN0ZW0SABoAIgAqJGU1NmFhMDVkLTFlYTgtMTFlNy04Y2Q3LWY0ZTlkNDlmOGVkMDIAOABCCwiJ+LLHBRDoq9ASegASDAoKa3ViZXJuZXRlcxoICgZBY3RpdmUaACIA",
            "version": 1
        },
        {
            "create_revision": 3774247,
            "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMvc3BhcmstY2x1c3Rlcg==",
            "mod_revision": 3774247,
            "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEoABCmYKDXNwYXJrLWNsdXN0ZXISABoAIgAqJDMyNjY3ZDVjLTM0YWMtMTFlNy1iZmJkLThhZjFlM2E3YzViZDIAOABCDAiA1cbIBRDU3YuAAVoVCgRuYW1lEg1zcGFyay1jbHVzdGVyegASDAoKa3ViZXJuZXRlcxoICgZBY3RpdmUaACIA",
            "version": 1
        },
        {
            "create_revision": 15212191,
            "key": "L3JlZ2lzdHJ5L25hbWVzcGFjZXMveWFybi1jbHVzdGVy",
            "mod_revision": 15212191,
            "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEn0KYwoMeWFybi1jbHVzdGVyEgAaACIAKiQ2YWNhNjk1Yi03N2Y5LTExZTctYmZiZC04YWYxZTNhN2M1YmQyADgAQgsI1qiKzAUQkoqxDloUCgRuYW1lEgx5YXJuLWNsdXN0ZXJ6ABIMCgprdWJlcm5ldGVzGggKBkFjdGl2ZRoAIgA=",
            "version": 1
        }
    ]
}

key的值是经过base64编码，需要解码后才能看到实际值，如：

$ echo L3JlZ2lzdHJ5L25hbWVzcGFjZXMvYXV0b21vZGVs|base64 -d

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：

/registry/ThirdPartyResourceData/istio.io/istioconfigs/default/route-rule-details-default
/registry/ThirdPartyResourceData/istio.io/istioconfigs/default/route-rule-productpage-default
/registry/ThirdPartyResourceData/istio.io/istioconfigs/default/route-rule-ratings-default
...
/registry/configmaps/default/namerctl-script
/registry/configmaps/default/namerd-config
/registry/configmaps/default/nginx-config
...
/registry/deployments/default/sdmk-page-sdmk
/registry/deployments/default/sdmk-payment-web
/registry/deployments/default/sdmk-report
...

以下是etcd中存储的kubernetes所有的元数据类型：

ThirdPartyResourceData
apiextensions.k8s.io
apiregistration.k8s.io
certificatesigningrequests
clusterrolebindings
clusterroles
configmaps
controllerrevisions
controllers
daemonsets
deployments
events
horizontalpodautoscalers
ingress
limitranges
minions
monitoring.coreos.com
namespaces
persistentvolumeclaims
persistentvolumes
poddisruptionbudgets
pods
ranges
replicasets
resourcequotas
rolebindings
roles
secrets
serviceaccounts
services
statefulsets
storageclasses
thirdpartyresources

使用etcdctl访问kubernetes数据

使用etcdctl访问kubernetes数据

参考