Why gRPC gateway 为什么是gRPC gateway

Why you should consider using the gRPC gateway 为什么你应该考虑使用gRPC gateway

etcd v3 使用gRPC作为它的通讯协议。 etcd项目包括了一个基于gRPC的Go client和一个通过gRPC和etcd集群进行通信的命令行工具：etcdctl。

对于不支持gRPC的语言，etcd提供了JSON API的项目：gRPC gateway。 For languages with no gRPC support, etcd provides a JSON gRPC gateway. 这个gateway提供一个RESTful代理，该代理将从HTTP/JSON请求转换为gRPC消息。

使用grpc gateway

The gateway accepts a JSON mapping for etcd’s protocol buffer message definitions. 注意keyandvalue字段被定义为字节数组，因此必须使用JSON进行base64编码。下面的例子使用curl，当然任意的其他的HTTP/JSON客户端也是可以的。

笔记

从etcd v3.3，gRPC gateway访问点已经改变了： gRPC gateway endpoint has changed since etcd v3.3:

  • etcd v3.2 or before uses only [CLIENT-URL]/v3alpha/*.
  • etcd v3.3 uses [CLIENT-URL]/v3beta/* while keeping [CLIENT-URL]/v3alpha/*.
  • etcd v3.4 uses [CLIENT-URL]/v3/* while keeping [CLIENT-URL]/v3beta/*.
    • [CLIENT-URL]/v3alpha/* is deprecated.
  • etcd v3.5 or later uses only [CLIENT-URL]/v3/*.
    • [CLIENT-URL]/v3beta/* is deprecated.

gRPC-gateway不支持使用TLS通用名称的身份验证 gRPC-gateway does not support authentication using TLS Common Name.

Put and get keys

Use the /v3/kv/range and /v3/kv/put services to read and write keys: 使用/v3/kv/range和/v3/kv/put服务来读和写keys：

<<COMMENT
https://www.base64encode.org/
foo is 'Zm9v' in Base64
bar 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"}

Watch keys

Use the /v3/watch service to watch 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"}}]}}

Transactions

使用/v3/kv/txn发出一个事物：

# target CREATE
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"}}}]}

# target VERSION
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"}}]}

Authentication 认证

给/v3/auth服务设置认证：

# create root user
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"}}

# create root role
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"}}

# grant root role
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"}}

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

Authenticate with etcd for an authentication token using /v3/auth/authenticate:

# get the auth token for the root user
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"}

Set the Authorization header to the authentication token to fetch a key using authentication credentials:

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"}}

Swagger

生成SwaggerAPI可以在rpc.swagger.json中找到。


May 16, 2021: translate api_grpc_gateway.md (504db91)