基于sanic的微服务框架 - 架构分析

感谢@songcser分享的《基于sanic的微服务基础架构》https://github.com/songcser/sanic-ms
最近正在学习微服务，发现这个repo不错，但不完整，跑不起来。所以学习了一下源码，实际使用Docker部署成功，本文记录实现过程。
学习用的git: https://github.com/kevinqqnj/sanic-ms

0. sanicms总体框架

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1. 微服务是什么

微服务架构是一种将单应用程序作为一套小型服务开发的方法，每种应用程序都在其自己的进程中运行，并与轻量级机制（通常是HTTP资源的API）进行通信。这些服务是围绕业务功能构建的，可以通过全自动部署机制进行独立部署。这些服务的集中化管理已经是最少的，它们可以用不同的编程语言编写，并使用不同的数据存储技术。

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http://baijiahao.baidu.com/s?id=1600354904549354089&wfr=spider&for=pc

2. 使用的功能模块

• sanic: 作为sevice服务的平台 https://sanic.readthedocs.io/en/latest/
• peewee：用于ORM，使用asyncpg为数据库异步驱动
• consul：用于服务发现、监控 https://www.consul.io/ https://python-consul.readthedocs.io/en/latest/
• opentracing/zipkin：分布式追踪系统，收集log，分析瓶颈
  https://zipkin.io/
• 使用swagger做API标准，能自动生成API文档。

Project structure

├── develop # 开发脚本
│ ├── cluster.sh
│ ├── reset.sh # 初始化项目
│ ├── test.sh
│ ├── utils.sh
│ ├── wait-for-it.sh
│ └── wait-service.sh
├── region_service # 微服务之1
│ ├── sanicms
│ ├── info.log
│ ├── migrations.py
│ ├── models.py
│ ├── server.py
│ ├── settings.py
│ └── views.py
├── role_service # 微服务之2
│ ├── ...
├── user_service # 微服务之3
│ ├── ...
├── sanicms # 微服务主框架
│ ├── _init.py
│ ├── client.py
│ ├── config.py
│ ├── db.py
│ ├── doc.py
│ ├── exception.py
│ ├── loggers.py
│ ├── logging.yml
│ ├── _main.py
│ ├── migrations.py
│ ├── openapi.py
│ ├── server.py
│ ├── service.py
│ ├── tests.py
│ └── utils.py
├── docker-compose-cluster.yml
├── docker-compose-service-cluster.yml
├── docker-compose.yml # Docker微服务服务的配置文件，包括db/zipkin/swagger/consul
├── Dockerfile # Docker微服务的基本环境包
├── pylintrc
├── README.md
└── requirements.txt # Python依赖模块

3. Docker部署

1. 安装Docker in Ubuntu (WSL): https://www.jianshu.com/p/97d16b68045f

2. git repo到本地
   git clone https://github.com/kevinqqnj/sanic-ms.git
cd sanic-ms

3. 调用脚本来配置docker-compose，初始化数据库

kevinqq@CN-00009841:/c/Users/xxx/git/sanic-ms$ ./develop/reset.sh
>>> stop existing services
Stopping sanic-ms_user_server_1     ... done
>>> removing existing services
Going to remove sanic-ms_user_server_1, sanic-ms_role_server_1, sanic-ms_region_server_1, sanic-ms_consul-server-2_1, sanic-ms_consul-server-1_1, sanic-ms_swagger_1, sanic-ms_consul-agent-1_1, sanic-ms_consul-agent-2_1, sanic-ms_zipkin_1, sanic-ms_db_1, sanic-ms_consul_1
Removing sanic-ms_user_server_1     ... done
>>> starting db/consul/zipkin
Creating sanic-ms_zipkin_1 ... done
Creating sanic-ms_consul_1 ... done
Creating sanic-ms_db_1     ... done
trying to >>> connect postgres 1
/var/run/postgresql:5432 - no response
trying to >>> connect postgres 2
/var/run/postgresql:5432 - accepting connections
>>> starting services
sanic-ms_consul_1 is up-to-date
sanic-ms_zipkin_1 is up-to-date
sanic-ms_db_1 is up-to-date
Creating sanic-ms_swagger_1         ... done
Creating sanic-ms_region_server_1   ... done
Creating sanic-ms_role_server_1     ... done
Creating sanic-ms_user_server_1     ... done
>>> create tables
Starting sanic-ms_db_1 ... done
Starting sanic-ms_zipkin_1 ... done
Starting sanic-ms_region_server_1 ... done
Starting sanic-ms_role_server_1   ... done
Success Migration

各服务端口：

kevinqq@CN-00009841:/c/Users/xxx/git/sanic-ms$ docker-compose ps
           Name                         Command               State                                             Ports
----------------------------------------------------------------------------------------------------------------------------------------------------------------
sanic-ms_consul-agent-1_1    docker-entrypoint.sh agent ...   Up      8300/tcp, 8301/tcp, 8301/udp, 8302/tcp, 8302/udp, 8500/tcp, 8600/tcp, 8600/udp
sanic-ms_consul-agent-2_1    docker-entrypoint.sh agent ...   Up      8300/tcp, 8301/tcp, 8301/udp, 8302/tcp, 8302/udp, 8500/tcp, 8600/tcp, 8600/udp
sanic-ms_consul-server-1_1   docker-entrypoint.sh agent ...   Up      8300/tcp, 8301/tcp, 8301/udp, 8302/tcp, 8302/udp, 8500/tcp, 8600/tcp, 8600/udp
sanic-ms_consul-server-2_1   docker-entrypoint.sh agent ...   Up      8300/tcp, 8301/tcp, 8301/udp, 8302/tcp, 8302/udp, 8500/tcp, 8600/tcp, 8600/udp
sanic-ms_consul_1            docker-entrypoint.sh agent ...   Up      8300/tcp, 8301/tcp, 8301/udp, 8302/tcp, 8302/udp, 0.0.0.0:8400->8400/tcp,
                                                                      0.0.0.0:8500->8500/tcp, 0.0.0.0:8600->8600/tcp, 0.0.0.0:8600->8600/udp
sanic-ms_db_1                docker-entrypoint.sh postgres    Up      0.0.0.0:55432->5432/tcp
sanic-ms_region_server_1     python -m server                 Up      0.0.0.0:8050->8050/tcp
sanic-ms_role_server_1       python -m server                 Up      0.0.0.0:8020->8020/tcp
sanic-ms_swagger_1           sh /usr/share/nginx/docker ...   Up      0.0.0.0:8090->8080/tcp
sanic-ms_user_server_1       python -m server                 Up      0.0.0.0:8030->8030/tcp
sanic-ms_zipkin_1            /bin/sh -c test -n "$STORA ...   Up      0.0.0.0:9410->9410/tcp, 0.0.0.0:9411->9411/tcp

4. 检查各个服务是否已正常运行

- consul服务发现

已经发现consul自己的集群，还有基于sanic的3个服务

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consul集群，可以看到5个nodes：在docker-compose文件里定义了consul-server-bootstrap x 1, server x 2, client x 2

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- sanic服务

目前演示了3个服务：user-service, role-service, region-service
添加一些测试数据：

kevinqq@CN-00009841:/c/Users/xxx/git/sanic-ms$ curl -X POST "http://localhost:8020/roles" -H  "accept: application/json" -H  "content-type: application/json" -d "{  \"name\": \"admin\"}"
{"code":0,"data":{"id":1}}

kevinqq@CN-00009841:/c/Users/xxx/git/sanic-ms$ curl -X POST "http://localhost:8030/users" -H  "accept: application/json" -H  "content-type: application/json" -d "{\"name\": \"Kevinqqnj\",\"age\":11,\"role_id\":1}"
{"code":0,"data":{"id":1}}

访问各个端口API:
user-service服务器：

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role-service服务器：

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演示跨服务器异步访问：

# user_service/views.py
@user_bp.get('/<id:int>', name="get_user")
async def get_user(request, id):
    async with request.app.db.acquire(request) as cur:
        records = await cur.fetch(
            """ SELECT * FROM users WHERE id = $1 """, id)
        records = records[0]
        datas = [
            [records, 'role_id', get_role_by_id(request, records['role_id'])]
        ]
        await async_request(datas)
        return records

async def get_role_by_id(request, id):
    cli = request.app.role_client.cli(request)
    async with cli.get('roles/{}'.format(id)) as res:
        return await res.json()

image.png

- zipkin分布式追踪系统

查看刚才的访问记录：
可以清晰地看到访问user_server/user/1，微服务里各节点的记录、消耗时间等

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- Swagger API文档自动生成

通过修改右上角server地址，可以查看其它sevice的API

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几个要点：

• 服务启动顺序非常重要！
  consul, zipkin必须在其它service之前启动，否则发现不了其它服务
  user_server启动须安排在role_server/region_server之后，不然Client服务创建会失败：

@app.listener('before_server_start')
async def before_srver_start(app, loop):
    app.region_client = Client('region-service', app=app)   # service name is APP-ID
    app.role_client = Client('role-service', app=app)

• 原repo，sanicms模块是作为python包安装的，不方便经常更新sanicms里的内容。所以我的repo里，sanicms是作为一个内部模块了，跟其它模块在同一级目录。

后续计划

• 添加www服务
• Sanic_session管理模块
• Cache: 选用aiocache + aioredis
• Sanic_JWT鉴权模块
• 异步数据库操作进阶: 超快的asyncpg + peewee/gino?
• 任务队列管理Celery
  sanic add_task feature is just wrapper on asyncio loop.create_task and nothing more. Asyncio tasks more like short processing and not for long background jobs.
• Sanic_WebSocket
• more...

参考：https://github.com/mfornos/awesome-microservices

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