fastapi 通过依赖注入模式使用apscheduler

就是一个简单记录，方便后续使用

参考代码

• api 服务

import uuid

from fastapi import FastAPI,Header,Depends,HTTPException

 

from typing import Annotated

 

async def tenant_id(x_tenant_id: Annotated[str, Header()]):

    if x_tenant_id != "demo":

        raise HTTPException(status_code=400, detail="X-Token header invalid")

    return x_tenant_id

 

from instance import SingleBackgroudScheduler

 

def apschedulere():

     instance = SingleBackgroudScheduler()

     if not instance.running:

         instance.start()

     return instance

 

app = FastAPI(dependencies=[Depends(tenant_id)])

 

scheduler = apschedulere()

 

@app.on_event("startup")

async def startup_event():

    if not scheduler.running:

        scheduler.start()

        print("scheduler started")

 

@app.on_event("shutdown")

async def shutdown_event():

    scheduler = apschedulere()

    if scheduler.running:

        scheduler.shutdown()

 

 

class DBContext():

    def __init__(self):

        self.name = "dalong"

 

@app.get("/")

async def add_task(scheduler: SingleBackgroudScheduler = Depends(apschedulere)):

    scheduler.add_job("mytask:my_job",name=str(uuid.uuid4()),id=str(uuid.uuid4()),kwargs={"name":"dalong","age":333,"job_args":{"name":"demo","id":333,"version":"v1"},"db_context":DBContext()},trigger='interval', seconds=5)

 

 

@app.get("/pause/{job_id}")

async def pause_job(job_id: str, scheduler: SingleBackgroudScheduler = Depends(apschedulere)):

    scheduler.pause_job(job_id)

 

 

@app.get("/jobs")

async def jobs(scheduler: SingleBackgroudScheduler = Depends(apschedulere)):

    return [ {"id":item.id,"name":item.name} for item in scheduler.get_jobs()]

if __name__ == "__main__":

    import uvicorn

    uvicorn.run(app, host="0.0.0.0", port=8000)

• SingleBackgroudScheduler 定义

"""

init one BackgroudScheduler

"""

import logging

from apscheduler.schedulers.background import BackgroundScheduler

from pytz import utc

from apscheduler.jobstores.sqlalchemy import SQLAlchemyJobStore

from apscheduler.executors.pool import ThreadPoolExecutor, ProcessPoolExecutor

 

logging.basicConfig()

logging.getLogger('apscheduler').setLevel(logging.INFO)

 

class SingleBackgroudScheduler:

    _instance = None

    def __new__(cls, *args, **kwargs):

        scheduler_config = {

            "db_connection": kwargs.get("db_connection", "sqlite:///jobs.sqlite"),

            "thread_pool": kwargs.get("thread_pool", 20),

            "process_pool": kwargs.get("process_pool", 5),

            "coalesce": kwargs.get("coalesce", False),

            "max_instances": kwargs.get("max_instances", 3),

        }

        if cls._instance is None:

            jobstores = {

                'default': SQLAlchemyJobStore(url=scheduler_config["db_connection"])

            }

            executors = {

                'default': ThreadPoolExecutor(scheduler_config["thread_pool"]),

                'processpool': ProcessPoolExecutor(scheduler_config["process_pool"])

            }

            job_defaults = {

                'coalesce': scheduler_config.get("coalesce", False),

                'max_instances': scheduler_config.get("max_instances", 3),

            }

            scheduler = BackgroundScheduler(jobstores=jobstores, executors=executors, job_defaults=job_defaults,

                                            timezone=utc)

            cls._instance = scheduler

            cls._instance.status_message = "BackgroundScheduler Initialized"

        return cls._instance

说明

核心上是添加了单例模式，之后通过Depends 将获取单例的BackgroundScheduler的方法进行注入，方便后续业务api 的使用

参考资料

https://fastapi.tiangolo.com/tutorial/dependencies/