通过Django管理周期性任务-feapder爬虫

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2023-02-21 / 0 评论 / 20 阅读 / 正在检测是否收录...

前言

功能实现

模型设计

后台管理

# Register your models here.
class SpiderInfofAdmin(admin.ModelAdmin):
    #后台展示字段
    list_display = ['id', 'sname', 'filepath', 'workpath', 'image', 'addtime', 'snote']

    #搜索字段
    search_fields = ['sname']

class SpiderTaskAdmin(admin.ModelAdmin):
    #后台展示字段
    list_display = ['id', 'sname', 'snote', 'addtime', 'runtime_show', 'total', 'repeat', 'valid', 'status_colored', 'operate']

    #过滤字段
    list_filter =  ["status"]

    #搜索字段
    search_fields = ['sname']

    #只读字段
    readonly_fields =  ['id', 'addtime', 'runtime', 'total', 'repeat', 'valid', 'status']

    #自定义动作
    actions = ['schedule_switch']

异步任务

  1. 项目主settings.py添加内容

    INSTALLED_APPS = [
     # 略
     'django_celery_beat',
     #略
    ]
    
    # Celery配置
    # BROKER和BACKEND配置,这里用了本地的redis,其中1和2表示分别用redis的第一个和第二个db
    CELERY_BROKER_URL = 'redis://172.17.0.10:6379/1'
    CELERY_RESULT_BACKEND = 'redis://172.17.0.10:6379/2'
    
    # CELERY 时间
    CELERY_TIMEZONE = TIME_ZONE
    DJANGO_CELERY_BEAT_TZ_AWARE = False
    
    #指定任务接收的内容序列化类型
    CELERY_ACCEPT_CONTENT = ['application/json']
    
    #任务和任务结果序列化方式
    CELERY_TASK_SERIALIZER = 'json'
    CELERY_RESULT_SERIALIZER = 'json'
    
    #超过时间
    CELERY_TASK_RESULT_EXPIRES = 12 * 30
    
    #是否压缩
    CELERY_MESSAGE_COMPRESSION = 'zlib'
    
    #并发数默
    CELERYD_CONCURRENCY = 2
    
    #celery worker 每次去redis取任务的数量认已CPU数量定
    CELERYD_PREFETCH_MULTIPLIER = 2
    
    #每个worker最多执行3个任务就摧毁,避免内存泄漏
    CELERYD_MAX_TASKS_PER_CHILD = 3
    
    #可以防止死锁
    CELERYD_FORCE_EXECV = True
    
    #celery 关闭UTC时区
    CELERY_ENABLE_UTC = False
    
    #celery 并发数设置,最多可以有20个任务同时运行
    CELERYD_CONCURRENCY = 20
    CELERYD_MAX_TASKS_PER_CHILD = 4
    
    #celery开启数据库调度器,数据库修改后即时生效
    CELERY_BEAT_SCHEDULER = 'django_celery_beat.schedulers:DatabaseScheduler'
    
    #解决告警
    DEFAULT_AUTO_FIELD = 'django.db.models.AutoField'

2.同目录下新增celery.py

import os
from celery import Celery,platforms
from django.conf import settings

# 设置环境变量
os.environ.setdefault('DJANGO_SETTINGS_MODULE','taskmon.settings')

# 实例化
app = Celery('taskmon')

# namespace='CELERY'作用是允许你在Django配置文件中对Celery进行配置
# 但所有Celery配置项必须以CELERY开头,防止冲突
app.config_from_object('django.conf:settings', namespace='CELERY')


# 自动从Django的已注册app中发现任务
app.autodiscover_tasks()

#允许root 用户运行celery
platforms.C_FORCE_ROOT = True

# 一个测试任务
@app.task(bind=True)
def debug_task(self):
  print('Request: {0!r}'.format(self.request))

3.项目目录下tasks.py

#操作docker
from celery import shared_task
from .utils import process_start

@shared_task
def sync_start_process(sname):
    """
    异步执行任务
    """
    process_start(sname)

4.celery启动

#任务调度
celery multi start worker  -A taskmon  -l info  --logfile=/logs/celery_worker.log
celery -A taskmon beat  -l info  --logfile=/logs/celery_beat.log

添加周期任务

删除周期任务

def remove_celery_task(sid):
    """
    删除计划任务
    sid : 爬虫任务ID
    """
    cname = str(sid) + '-' + '周期任务'
    #添加计划任务
    with transaction.atomic():
        save_id = transaction.savepoint()
        try:
            _p = PeriodicTask.objects.get(name=cname)
            if _p:
                _p.delete()
                print('{}删除计划任务成功'.format(cname))
            return True
        except Exception as e:
            transaction.savepoint_rollback(save_id)
            print('{}删除计划任务失败,错误原因:'.format(cname) + str(e))
            return False

任务启动函数

def process_start(sname):
    """
    执行任务并处理返回结果
    sname: 任务名
    cinfo: 启动容器所需的信息
    """
    con_name = 'spider_{}_1'.format(sname)
    containers = get_containers({"name":con_name})

    if containers:
        print('有相同任务运行中...|{}|{}'.format(con_name, datetime.datetime.now().strftime("%Y-%m-%d-%H-%M-%S")))
        return False

    #查询库
    spider_task = SpiderTask.objects.get(sname=sname)

    #构建docker启动信息
    cinfo = {
            "name": con_name,
            "command": spider_task.command,
            #宿主机目录
            "volumes": ['/opt/project/taskmon/myapp/spider/{}:{}'.format(spider_task.sinfo.filepath, spider_task.sinfo.workpath),],
            "shm_size": spider_task.sinfo.shm,
            "image": spider_task.sinfo.image,
            "working_dir": spider_task.sinfo.workpath,
            "remove": False,
        }

    #启动容器
    result = run_container(cinfo)

    if result:
        #日志文件
        log_path='/logs/{}_{}.log'.format(con_name, datetime.datetime.now().strftime("%H-%M-%S-%Y-%m-%d"))

        #保存日志
        with open(log_path, 'wb') as fw:
            fw.write(result)

        #采集结果
        d_nums = process_result(result)

        #更新
        spider_task.total = d_nums[0]
        spider_task.repeat = d_nums[1]
        spider_task.valid = d_nums[2]
        spider_task.logpath = log_path
        spider_task.save()

    print('任务执行...|{}|{}'.format(con_name, datetime.datetime.now().strftime("%Y-%m-%d-%H-%M-%S")))

容器启动函数

def run_container(ddict):
    """
    运行容器
    """
    #print(ddict)
    container = client.containers.run(
        image=ddict['image'],
        name=ddict['name'],
        shm_size=ddict['shm_size'],
        volumes=ddict['volumes'],
        working_dir=ddict['working_dir'],
        remove=ddict['remove'],
        detach=True,
        command=ddict['command']
    )
    container.wait()
    result = container.logs()
    container.remove()
    return result

结果处理函数

def process_result(result):
    """
    处理返回结果
    """
    a = 0
    b = 0
    c = 0
    lines = str(result, encoding = "utf-8").split('\n')
    for line in lines:
        if '待入库数据' in line:
            tmp_s = line.split('|')[3]
            nums = tmp_s.split(' ')
            a += int(nums[2])
            b += int(nums[5])
            c += int(nums[7])
    return (a, b, c)

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FAQ

自动添加周期任务后,启动报错

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