ETCD:HTTP JSON API通过gRPC网关

原文地址:HTTP JSON API through the gRPC gateway

etcd v3 使用 gRPC 作为消息协议。etcd项目包括一个基于gRPC的Go客户端和一个命令行工具，etcdctl,通过gRPC与etcd集群进行交互.对于没有gRPC支持的语言，etcd提供JSON gRPC网关，这个网关提供一个RESTful风格的代理可以将HTTP/JSON请求转换为gRPC消息。

使用 gRPC网关

这个网关接受一个到etcd's buffer协议消息定义的JSON格式的映射,注意Key和Value字段定义为byte 数组，因此JSON必须使用base64编码,下面的例子使用curl,但是每个HTTP/JSON客户端的工作原理都和例子相同。

注意

gRPC网关节点从etcd v3.3发生变化：

etcd v3.2以及之前版本只使用[CLIENT-URL]/v3alpha/*。
etcd v3.3使用[CLIENT-URL]/v3beta/*保持[CLIENT-URL]/v3alpha/*使用。
etcd v3.4使用[CLIENT-URL]/v3/*保持[CLIENT-URL]/v3beta/*使用。
- [CLIENT-URL]/v3alpha/*被抛弃使用。
etcd v3.5以及最新版本只使用[CLIENT-URL]/v3/*。
- [CLIENT-URL]/v3beta/*被抛弃使用。

存储和获取Keys

使用/v3/kv/range和/v3/kv/put服务读和写Keys:

<<COMMENThttps://www.base64encode.org/foo is 'Zm9v' in Base64bar is 'YmFy'COMMENT

curl -L http://localhost:2379/v3/kv/put \

  -X POST -d '{"key": "Zm9v", "value": "YmFy"}'# {"header":{"cluster_id":"12585971608760269493","member_id":"13847567121247652255","revision":"2","raft_term":"3"}}

curl -L http://localhost:2379/v3/kv/range \

  -X POST -d '{"key": "Zm9v"}'# {"header":{"cluster_id":"12585971608760269493","member_id":"13847567121247652255","revision":"2","raft_term":"3"},"kvs":[{"key":"Zm9v","create_revision":"2","mod_revision":"2","version":"1","value":"YmFy"}],"count":"1"}

# get all keys prefixed with "foo"

curl -L http://localhost:2379/v3/kv/range \

  -X POST -d '{"key": "Zm9v", "range_end": "Zm9w"}'# {"header":{"cluster_id":"12585971608760269493","member_id":"13847567121247652255","revision":"2","raft_term":"3"},"kvs":[{"key":"Zm9v","create_revision":"2","mod_revision":"2","version":"1","value":"YmFy"}],"count":"1"}

查看 Keys

使用/v3/watch服务查看Keys:

curl -N http://localhost:2379/v3/watch \

  -X POST -d '{"create_request": {"key":"Zm9v"} }' &# {"result":{"header":{"cluster_id":"12585971608760269493","member_id":"13847567121247652255","revision":"1","raft_term":"2"},"created":true}}

curl -L http://localhost:2379/v3/kv/put \

  -X POST -d '{"key": "Zm9v", "value": "YmFy"}' >/dev/null 2>&1# {"result":{"header":{"cluster_id":"12585971608760269493","member_id":"13847567121247652255","revision":"2","raft_term":"2"},"events":[{"kv":{"key":"Zm9v","create_revision":"2","mod_revision":"2","version":"1","value":"YmFy"}}]}}

交易

使用``/v3/kv/txn`发行一个交易：

# 目标创建

curl -L http://localhost:2379/v3/kv/txn \

  -X POST \

  -d '{"compare":[{"target":"CREATE","key":"Zm9v","createRevision":"2"}],"success":[{"requestPut":{"key":"Zm9v","value":"YmFy"}}]}'# {"header":{"cluster_id":"12585971608760269493","member_id":"13847567121247652255","revision":"3","raft_term":"2"},"succeeded":true,"responses":[{"response_put":{"header":{"revision":"3"}}}]}

# 目标版本

curl -L http://localhost:2379/v3/kv/txn \

  -X POST \

  -d '{"compare":[{"version":"4","result":"EQUAL","target":"VERSION","key":"Zm9v"}],"success":[{"requestRange":{"key":"Zm9v"}}]}'# {"header":{"cluster_id":"14841639068965178418","member_id":"10276657743932975437","revision":"6","raft_term":"3"},"succeeded":true,"responses":[{"response_range":{"header":{"revision":"6"},"kvs":[{"key":"Zm9v","create_revision":"2","mod_revision":"6","version":"4","value":"YmF6"}],"count":"1"}}]}

权限

使用/v3/auth设置权限：

# 创建root用户

curl -L http://localhost:2379/v3/auth/user/add \

  -X POST -d '{"name": "root", "password": "pass"}'# {"header":{"cluster_id":"14841639068965178418","member_id":"10276657743932975437","revision":"1","raft_term":"2"}}

# 创建root角色

curl -L http://localhost:2379/v3/auth/role/add \

  -X POST -d '{"name": "root"}'# {"header":{"cluster_id":"14841639068965178418","member_id":"10276657743932975437","revision":"1","raft_term":"2"}}

# 授予root角色

curl -L http://localhost:2379/v3/auth/user/grant \

  -X POST -d '{"user": "root", "role": "root"}'# {"header":{"cluster_id":"14841639068965178418","member_id":"10276657743932975437","revision":"1","raft_term":"2"}}

# 开启认证

curl -L http://localhost:2379/v3/auth/enable -X POST -d '{}'# {"header":{"cluster_id":"14841639068965178418","member_id":"10276657743932975437","revision":"1","raft_term":"2"}}

通过/v3/auth/authenticate服务使用一个认证令牌进行认证:

# 为根用户获取认证令牌

curl -L http://localhost:2379/v3/auth/authenticate \

  -X POST -d '{"name": "root", "password": "pass"}'# {"header":{"cluster_id":"14841639068965178418","member_id":"10276657743932975437","revision":"1","raft_term":"2"},"token":"sssvIpwfnLAcWAQH.9"}

使用认证证书设置认证头部到认证令牌获取Keys：

curl -L http://localhost:2379/v3/kv/put \

  -H 'Authorization : sssvIpwfnLAcWAQH.9' \

  -X POST -d '{"key": "Zm9v", "value": "YmFy"}'# {"header":{"cluster_id":"14841639068965178418","member_id":"10276657743932975437","revision":"2","raft_term":"2"}}