通过Django管理周期性任务-feapder爬虫

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2023-02-21 / 0 评论 / 476 阅读 / 正在检测是否收录...

前言

一开始感兴趣的信息比较少,直接用crontab启动就满足要求了。后台爬虫越来越多,有的爬虫早就失效了,也没发现。用了 feapder 作者的管理系统 feaplat 。系统功能很全面,但是随着功能的完善,价格也越来越贵。个人实在承担不起,只能花时间自己搞一个简易版的了。

功能实现

模型设计

# Create your models here.
class SpiderInfo(models.Model):
    '''
    爬虫项目信息类
    '''
    id = models.AutoField(primary_key=True)
    sname = models.CharField(max_length=64, verbose_name='项目名称')
    filepath   = models.CharField(max_length=64, verbose_name='项目路径')
    workpath   = models.CharField(max_length=64, verbose_name='工作路径')
    image    = models.CharField(max_length=64, verbose_name='镜像', default='feapder23')
    shm = models.CharField(max_length=32, default='64M', verbose_name='虚拟内存')
    addtime = models.DateTimeField(auto_now_add=True, verbose_name='添加时间')
    snote = models.CharField(max_length=255, verbose_name='说明')

    # admin显示订单的id
    def __str__(self):
        return self.sname

    class Meta:
        db_table = 'spider_info'
        verbose_name = '爬虫项目'
        verbose_name_plural = '爬虫项目'

# Create your models here.
class SpiderTask(models.Model):
    '''
    爬虫任务管理类
    '''
    id = models.AutoField(primary_key=True)
    status_choices = ((k, v) for k,v in STATUS_CHOICE.items())
    sname = models.CharField(max_length=64, unique=True,verbose_name='任务名')
    snote =  models.CharField(max_length=128, blank=True,verbose_name='说明')
    command = models.CharField(max_length=128, verbose_name='启动命令')
    status = models.SmallIntegerField(default='0', choices=status_choices, verbose_name='调度状态')
    crond = models.CharField(max_length=32, blank=True, verbose_name='计划任务')
    addtime = models.DateTimeField(auto_now_add=True, verbose_name='添加时间')
    runtime = models.DateTimeField(auto_now=True, blank=True, verbose_name='最后运行时间')
    total = models.IntegerField(default=0, verbose_name='总数')
    repeat = models.IntegerField(default=0, verbose_name='重复')
    valid = models.IntegerField(default=0, verbose_name='入库')
    logpath = models.CharField(max_length=128, blank=True, verbose_name='日志')
    sinfo = models.ForeignKey(SpiderInfo, on_delete=models.CASCADE, default='')

    # admin显示订单的id
    def __str__(self):
        return self.sname

    class Meta:
        db_table = 'spider_task'
        verbose_name = '爬虫任务'
        verbose_name_plural = '爬虫任务'

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.修改__init__.py,加载celery配置

#注册celery
from .celery import app as celery_app
__all__ = ('celery_app',)

4.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)
5.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

def add_celery_task(sid):
    """
    新增计划任务
    sid : 爬虫任务ID
    """
    stask = SpiderTask.objects.get(id=sid)
    cname = str(stask.id) + '-' + '周期任务'

    c_arry = stask.crond.strip().split()
    print(c_arry)

    #添加计划任务
    with transaction.atomic():
        save_id = transaction.savepoint()
        try:
            _c, created = CrontabSchedule.objects.get_or_create(
                minute=str(c_arry[0]),
                hour=str(c_arry[1]),
                day_of_week=str(c_arry[2]),
                day_of_month=str(c_arry[3]),
                month_of_year=str(c_arry[4])
            )

            _p = PeriodicTask.objects.create(
                name= cname,
                task='spider.tasks.sync_start_process',
                args='["{}"]'.format(stask.sname),
                enabled=True,
                crontab=_c
            )

            print('{}计划任务添加成功'.format(cname))
            return True
        except Exception as e:
            transaction.savepoint_rollback(save_id)
            print('{}添加计划任务失败,错误原因:'.format(cname) + str(e))
            return False

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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  1. 头像
    chenyapeng
    · MacOS · Google Chrome
    沙发

    受益匪浅,感谢博主。

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