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GoCoding

2021/11/05  阅读:24  主题:默认主题

OpenAPITools 实践

OpenAPITools 可以依据 REST API 描述文件,自动生成服务端桩(Stub)代码、客户端 SDK 代码,及文档等。其是社区版的 Swagger ,差异可见:OpenAPI Generator vs Swagger Codegen

本文将从零开始设计和编写 API 文件,并生成 Go Gin 服务端代码,与 Python SDK 代码。更多语言或框架,也是一样操作的。

快速开始

先熟悉下工具,直接用官方 Docker 镜像生成 Petstore 样例的 Go SDK 代码:

docker run --rm -v "${PWD}:/local" openapitools/openapi-generator-cli generate \
-i https://raw.githubusercontent.com/openapitools/openapi-generator/master/modules/openapi-generator/src/test/resources/3_0/petstore.yaml \
-g go \
-o /local/out/go

生成代码在当前目录的 ./out/go

打开 Swagger Editor File > Import URL 查看 petstore.yaml API:

查看 openapi-generator-cli 用法:

docker run --rm -it \
-v "${PWD}:/local" \
--entrypoint /bin/bash \
openapitools/openapi-generator-cli

ln -s /usr/local/bin/docker-entrypoint.sh /usr/local/bin/openapi-generator
openapi-generator help
openapi-generator help generate

动手实践

设计 RESTful API

打开 Swagger Editor 设计 API:

  • /albums
    • GET - Get all albums
    • POST - Create a new album
  • /albums/:id
    • GET - Get an album by its id
    • PUT - Update an album by its id
    • DELETE - Delete an album by its id

完整 API 描述文件见 spec/api.yaml,主要包含三部分:

  1. 头部: API 信息

    openapi: 3.0.0
    info:
      title: Start OpenAPITools
      description: Let's practice designing our api.
      version: 0.1.0
      license:
        name: MIT
        url: https://spdx.org/licenses/MIT.html
    servers:
      - url: https://github.com/ikuokuo/start-openapitools
  2. 中间: paths 及其操作 (get, post, etc.)

    paths:
      /albums/{id}:
        get:
          tags:
            - album
          summary: Get an album by its id
          operationId: getAlbum
          parameters:
            - $ref: '#/components/parameters/AlbumId'
          responses:
            200:
              description: Get success, return the album
              content:
                application/json:
                  schema:
                    $ref: '#/components/schemas/Album'
            404:
              description: Album not found
  3. 底部: 可重用的 components,于文档里 $ref 引用

    components:
      parameters:
        AlbumId:
          name: id
          in: path
          description: Album id
          required: true
          schema:
            type: string
      schemas:
        Album:
          title: Album
          type: object
          required:
            - title
            - artist
            - price
          properties:
            id:
              type: string
              format: uuid
            title:
              type: string
              maxLength: 200
              minLength: 1
            artist:
              type: string
              maxLength: 100
              minLength: 1
            price:
              type: number
              format: double
              minimum: 0.0
            created_at:
              type: string
              format: date-time
            updated_at:
              type: string
              format: date-time

具体说明,请阅读 OpenAPI Specification

在线生成代码

可以用线上服务快速生成代码:

  • latest stable version: https://api.openapi-generator.tech

以下则是自己动手生成的过程。

生成 Server Stub 代码

生成 Go Gin 桩(Stub)代码:

docker run --rm -it \
-v "${PWD}:/local" \
--entrypoint /bin/bash \
openapitools/openapi-generator-cli

ln -s /usr/local/bin/docker-entrypoint.sh /usr/local/bin/openapi-generator

# Config Options for go-gin-server
#  https://openapi-generator.tech/docs/generators/go-gin-server
openapi-generator config-help -g go-gin-server

openapi-generator generate \
-g go-gin-server \
-i /local/spec/swagger.yaml \
-o /local/out/gin-server \
--additional-properties=packageName=startapi

生成内容:

❯ tree out/gin-server -aF --dirsfirst
out/gin-server
├── .openapi-generator/
├── api/
│   └── openapi.yaml
├── go/
│   ├── README.md
│   ├── api_album.go
│   ├── api_albums.go
│   ├── model_album.go
│   └── routers.go
├── .openapi-generator-ignore
├── Dockerfile
└── main.go

简单实现 GetAlbum 接口,位于 go/api_album.go

// GetAlbum - Get an album by its id
func GetAlbum(c *gin.Context) {
 c.JSON(http.StatusOK, Album{
  Id:        "3fa85f64-5717-4562-b3fc-2c963f66afa6",
  Title:     "Start OpenAPITools",
  Artist:    "GoCoding",
  Price:     0.99,
  CreatedAt: time.Now(),
  UpdatedAt: time.Now(),
 })
}

运行服务:

cd out/gin-server/
# 初始化模块
go mod init github.com/ikuokuo/start-openapitools/gin-server
go mod tidy

# 修改 `main.go` 中的 import 路径
#  sw "github.com/ikuokuo/start-openapitools/gin-server/go"
# 替换成本地路径
go mod edit -replace github.com/ikuokuo/start-openapitools/gin-server/go=./go

运行结果:

❯ go run .
2021/11/05 18:20:00 Server started
[GIN-debug] [WARNING] Creating an Engine instance with the Logger and Recovery middleware already attached.

[GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production.
 - using env:   export GIN_MODE=release
 - using code:  gin.SetMode(gin.ReleaseMode)

[GIN-debug] GET    /ikuokuo/start-openapitools/ --> github.com/ikuokuo/start-openapitools/gin-server/go.Index (3 handlers)
[GIN-debug] DELETE /ikuokuo/start-openapitools/albums/:id --> github.com/ikuokuo/start-openapitools/gin-server/go.DeleteAlbum (3 handlers)
[GIN-debug] GET    /ikuokuo/start-openapitools/albums/:id --> github.com/ikuokuo/start-openapitools/gin-server/go.GetAlbum (3 handlers)
[GIN-debug] PUT    /ikuokuo/start-openapitools/albums/:id --> github.com/ikuokuo/start-openapitools/gin-server/go.PutAlbum (3 handlers)
[GIN-debug] GET    /ikuokuo/start-openapitools/albums --> github.com/ikuokuo/start-openapitools/gin-server/go.GetAlbums (3 handlers)
[GIN-debug] POST   /ikuokuo/start-openapitools/albums --> github.com/ikuokuo/start-openapitools/gin-server/go.PostAlbums (3 handlers)
[GIN-debug] Listening and serving HTTP on :8080

❯ curl http://localhost:8080/ikuokuo/start-openapitools/
Hello World!

生成 Client SDK 代码

生成 Python SDK 代码:

docker run --rm -it \
-v "${PWD}:/local" \
--entrypoint /bin/bash \
openapitools/openapi-generator-cli

ln -s /usr/local/bin/docker-entrypoint.sh /usr/local/bin/openapi-generator

# Config Options for python
#  https://openapi-generator.tech/docs/generators/python
openapi-generator config-help -g python

openapi-generator generate \
-g python \
-i /local/spec/swagger.yaml \
-o /local/out/py-sdk \
--additional-properties=packageName=startapi \
--additional-properties=library=urllib3

生成内容:

❯ tree out/py-sdk -aF --dirsfirst
out/py-sdk
├── .openapi-generator/
├── docs/
├── startapi/
│   ├── api/
│   │   ├── __init__.py
│   │   ├── album_api.py
│   │   └── albums_api.py
│   ├── apis/
│   │   └── __init__.py
│   ├── model/
│   │   ├── __init__.py
│   │   └── album.py
│   ├── models/
│   │   └── __init__.py
│   ├── __init__.py
│   ├── api_client.py
│   ├── configuration.py
│   ├── exceptions.py
│   ├── model_utils.py
│   └── rest.py
├── test/
├── .gitignore
├── .gitlab-ci.yml
├── .openapi-generator-ignore
├── .travis.yml
├── README.md
├── git_push.sh
├── requirements.txt
├── setup.cfg
├── setup.py
├── test-requirements.txt
└── tox.ini

测试 SDK 使用,调用此前实现的 GetAlbum 接口:

❯ cd out/py-sdk/
❯ python - <<EOF
from startapi import ApiClient, Configuration, apis

config = Configuration(host="http://localhost:8080/ikuokuo/start-openapitools")
with ApiClient(configuration=config) as client:
  api = apis.AlbumApi(client)
  album = api.get_album("xxxxx")
  print(album)
EOF
{'artist''GoCoding',
 'created_at': datetime.datetime(2021, 11, 5, 18, 30, 0, 545305, tzinfo=tzoffset(None, 28800)),
 'id''3fa85f64-5717-4562-b3fc-2c963f66afa6',
 'price': 0.99,
 'title''Start OpenAPITools',
 'updated_at': datetime.datetime(2021, 11, 5, 18, 30, 0, 545305, tzinfo=tzoffset(None, 28800))}

最后

实践下来,感觉不错。很多场合,生成 SDK 就够用了。另外,生成自动化测试代码,也值得一试。

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GoCoding

2021/11/05  阅读:24  主题:默认主题

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