AsyncAPI 试用

AsyncAPI 提供了类似openapi的代码生成，以下demo，来自官方，只是目前官方的generator有些问题以下
同时说明运行中的一些问题

环境准备

主要是安装依赖组件

npm install -g asyncapi-generator mqtt

定义AsyncAPI

稍有改动，主要是channel（mqtt 的topic）

  • yaml 文件
asyncapi: '2.0.0'
info:
  title: Streetlights API
  version: '1.0.0'
  description: |
    The Smartylighting Streetlights API allows you
    to remotely manage the city lights.
  license:
    name: Apache 2.0
    url: 'https://www.apache.org/licenses/LICENSE-2.0'
​
servers:
  mosquitto:
    url: test.mosquitto.org
    protocol: mqtt
​
channels:
  dalong/measured:
    publish:
      summary: Inform about environmental lighting conditions for a particular streetlight.
      message:
        payload:
          type: object
          properties:
            id:
              type: integer
              minimum: 0
              description: Id of the streetlight.
            lumens:
              type: integer
              minimum: 0
              description: Light intensity measured in lumens.
            sentAt:
              type: string
              format: date-time
              description: Date and time when the message was sent.
​
  • 生成代码命令
ag asyncapi.yaml nodejs -p server=mosquitto
  • 简单说明
    如果直接使用url test.mosquitto.org 会有解析的问题，如下：
 
Something went wrong:
Template render error: (unknown path) [Line 29, Column 36]
  TypeError [ERR_INVALID_URL]: Invalid URL: test.mosquitto.org
    at Object._prettifyError (/usr/local/lib/node_modules/asyncapi-generator/node_modules/nunjucks/src/lib.js:36:11)
    at /usr/local/lib/node_modules/asyncapi-generator/node_modules/nunjucks/src/environment.js:567:19
    at Template.root [as rootRenderFunc] (eval at _compile (/usr/local/lib/node_modules/asyncapi-generator/node_modules/nunjucks/src/environmen
t.js:637:18), <anonymous>:83:3)
    at Template.render (/usr/local/lib/node_modules/asyncapi-generator/node_modules/nunjucks/src/environment.js:556:10)
    at Environment.renderString (/usr/local/lib/node_modules/asyncapi-generator/node_modules/nunjucks/src/environment.js:380:17)
    at Promise (/usr/local/lib/node_modules/asyncapi-generator/lib/generator.js:507:21)
    at new Promise (<anonymous>)
    at Generator.renderString (/usr/local/lib/node_modules/asyncapi-generator/lib/generator.js:506:12)
    at Generator.renderFile (/usr/local/lib/node_modules/asyncapi-generator/lib/generator.js:531:19)
    at <anonymous>
 

解决方法：临时修改为一个url 格式的比如test.mosquitto.org:1883 生成代码之后再修改回来

  • 生成效果
Done! ✨
Check out your shiny new generated files at /Users/dalong/mylearning/asyncapi-learning/first/streetlights.
 

 

 

 

  • 修改几处生成的代码
    配置文件：
    config/common.yml:
    如下：
 
default:
  app:
    name: Streetlights API
    version: 1.0.0
​
  broker:
    mqtt:
      url: mqtt://test.mosquitto.org
      topics: ["dalong/measured"]
      qos:
      protocol: mqtt
      retain:
      subscribe: true
​
development:
​
test:
​
staging:
​
production:
​
 
 

路由以及handler修改：
路由：

 

 

 


随便些一个名字，注意后边handler 需要和这个一样

 

 

 

启动&&测试

  • 安装npm依赖
 
yarn
  • 启动
yarn start
  • 模拟消息发送
mqtt pub -t 'dalong/measured' -h 'test.mosquitto.org' -m '{"id": 1111, "lumens": 3, "sentAt": "2019-10-06T12:34:32.000Z"}'
  • 效果

 

 

说明

以上是一个简单的试用，以及在使用中碰到的问题，AsyncAPI 是一个很不错的编写事件驱动应用的指南

参考资料

https://www.asyncapi.com/docs/tutorials/streetlights/
https://github.com/asyncapi/generator
http://test.mosquitto.org/
https://github.com/rongfengliang/asyncapi-streetlights-demo

posted on 2019-10-06 14:52  荣锋亮  阅读(1254)  评论(0)  编辑  收藏  举报

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