using etcdctl to access kuberentes data

SUMMARY.md

@@ -48,6 +48,7 @@
     - [docker用户过度到kubectl命令行指南](guide/docker-cli-to-kubectl.md)
     - [kubectl命令概览](guide/using-kubectl.md)
     - [kubectl命令技巧大全](guide/kubectl-cheatsheet.md)
+    - [使用etcdctl访问kuberentes数据](guide/using-etcdctl-to-access-kubernetes-data.md)
 - [集群安全性管理](guide/cluster-security-management.md)
   - [管理集群中的TLS](guide/managing-tls-in-a-cluster.md)
   - [kubelet的认证授权](guide/kubelet-authentication-authorization.md)
@@ -134,6 +135,7 @@
   - [Spark standalone on Kubernetes](usecases/spark-standalone-on-kubernetes.md)
   - [运行支持kubernetes原生调度的Spark程序](usecases/running-spark-with-kubernetes-native-scheduler.md)
 - [Serverless架构](usecases/serverless.md)
+  - [理解Serverless](usecases/understanding-serverless.md)
 - [边缘计算](usecases/edge-computing.md)
 
 ### 开发指南

guide/using-etcdctl-to-access-kubernetes-data.md

@@ -0,0 +1,122 @@
+# 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。
+
+```bash
+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：
+
+```json
+{
+    "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
+        }
+    ]
+}
+```
+
+使用`--prefix`可以看到所有的子目录，如查看集群中的namespace：
+
+```bash
+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。
+
+```bash
+{
+    "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,
+            "value": "azhzAAoPCgJ2MRIJTmFtZXNwYWNlEmEKRwoFYnJhbmQSABoAIgAqJGNkZmQ1Y2NmLWExYzktMTFlNy05NzBjLWY0ZTlkNDlmOGVkMDIAOABCDAjR9qLOBRDYn83XAXoAEgwKCmt1YmVybmV0ZXMaCAoGQWN0aXZlGgAiAA==",
+            "version": 1
+        },
+        {
+            "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：
+
+```bash
+$ echo L3JlZ2lzdHJ5L25hbWVzcGFjZXMvYXV0b21vZGVs|base64 -d
+/registry/namespaces/automodel
+```
+
+## 参考
+
+- [etcd中文文档](https://github.com/doczhcn/etcd)
+- [etcd官方文档](https://coreos.com/etcd/docs/latest/)

practice/etcd-cluster-installation.md

@@ -121,3 +121,6 @@ cluster is healthy
 ```
 
 结果最后一行为 `cluster is healthy` 时表示集群服务正常。
+
+关于如何在etcd中查看kubernetes的数据，请参考[使用etcdctl访问kuberentes数据](../guide/using-etcdctl-to-access-kubernetes-data.md)。
+