Django-从amazonS3中删除文件

Question

我遇到了一个问题，从中删除对象时，管理员不会删除与之相关的文件。经过一些研究，我决定在模型中实现post_delete。出于某种原因，我无法让s3删除该文件，即使在搜索了大量指南和片段之后，也许这里的人知道。我使用django 1.5和boto。这是我的型号代码：

from django.db import models
from django.contrib.auth.models import User
from fileservice.formatChecker import ContentTypeRestrictedFileField
from south.modelsinspector import add_introspection_rules
import os
from django.dispatch import receiver
from django.utils.translation import ugettext_lazy as _
from django.core.files.storage import default_storage as storage
add_introspection_rules([
    (
        [ContentTypeRestrictedFileField], # Class(es) these apply to
        [],         # Positional arguments (not used)
        {           # Keyword argument
            "content_types": ["content_types", {}],
            "max_upload_size": ["max_upload_size", {}]
        },
    ),
], ["^fileservice.formatChecker.ContentTypeRestrictedFileField"])
class Contentfile(models.Model):
    content = ContentTypeRestrictedFileField(upload_to='uploads/', content_types=['video/mp4', 'application/pdf', 'image/gif', 'image/jpeg', 'image/png'],max_upload_size=5242880,blank=True, null=True, help_text='Upload a file to add it to the content the app displayes')
    created_at = models.DateTimeField(auto_now_add=True, editable=False)
    updated_at = models.DateTimeField(auto_now=True, editable=False)
    title = models.CharField(max_length=255, unique=True)
    file_type = models.CharField(max_length=5)
    published = models.BooleanField(default=True)
    file_owner = models.ForeignKey(User, related_name='Contentfiles')
    class Meta:
        ordering = ["title"]
    def __unicode__(self):
        return self.title
    def save(self, *args, **kwargs):
        file_name = os.path.basename(self.content.name)
        self.file_type = file_name.split('.')[-1]
        self.title = file_name.split('.')[0]
        self.published = True
        super(Contentfile, self).save(*args, **kwargs)

@receiver(models.signals.post_delete, sender=Contentfile)
def auto_delete_file_on_delete(sender, instance, **kwargs):
    """Deletes file from filesystem
    when corresponding `MediaFile` object is deleted.
    """
    if instance.content:
        if os.path.isfile(storage.open(instance.content.path)):
            os.remove(storage.open(instance.content.path))
@receiver(models.signals.pre_save, sender=Contentfile)
def auto_delete_file_on_change(sender, instance, **kwargs):
    """Deletes file from filesystem
    when corresponding `MediaFile` object is changed.
    """
    if not instance.pk:
        return False
    try:
        old_file = Contentfile.objects.get(pk=instance.pk).content
    except Conentfile.DoesNotExist:
        return False
    new_file = instance.content
    if not old_file == new_file:
        if os.path.isfile(storage.open(old_file.path)):
            os.remove(storage.open(old_file.path))

Answer 1

执行post_delete更安全。如果出现问题，您将开始丢失S3文件，并且您不会注意到它，因为您的DB记录是完整的。post_delete会更安全，因为在您删除数据库记录后，S3删除操作失败的可能性较小。此外，即使文件删除失败，您也会留下一堆未引用的S3文件，这些文件是无害的，可以很容易地清理。

@receiver(models.signals.post_delete, sender=Picture)
def remove_file_from_s3(sender, instance, using, **kwargs):
    instance.img.delete(save=False)

Answer 2

您需要调用FieldFile的delete()方法来删除S3中的文件。在您的情况下，在您称之为的地方添加pre_delete信号

@receiver(models.signals.pre_delete, sender=ContentFile)
def remove_file_from_s3(sender, instance, using):
    instance.content.delete(save=False)

Answer 3

尝试django清理，当您删除模型时，它会自动调用FileField上的delete方法。

Answer 4

这对我来说很有效，删除了DB和AWS S3中的文件。

from django.db import models
from django.dispatch import receiver
from django.views import generic
from project.models import ContentFile
from django.contrib.auth.mixins import LoginRequiredMixin,UserPassesTestMixin
class DeleteFileView(LoginRequiredMixin,UserPassesTestMixin,generic.DeleteView):
   model = ContentFile
   template_name = 'file-delete.html'
   success_url = 'redirect-to'
   #Check if the owner of the file is the one trying to delete a file
   def test_func(self):
      obj = self.get_object()
      if obj.user == self.request.user:
        return True
      return False
    #This code does magic for S3 file deletion 
    @receiver(models.signals.pre_delete, sender=ContentFile)
    def remove_file_from_s3(sender, instance, using, **kwargs):
       instance.image_file.delete(save=False)

我使用的是pre_delete，您可以查看django文档。数据库中的文件引用删除是由DeleteView完成的，我希望这能帮助