Django应用对接IBM COS默认存储配置错误，无法写入数据库问题

问题根因 #

1. django-storages的S3Boto3Storage默认读取AWS前缀的配置项，你使用了IBM前缀的键名，导致存储类无法获取到bucket名称，触发类型错误
2. 视图中手动实现了上传逻辑，但没有绑定已上传文件的路径，Django仍会尝试对表单中的文件对象做二次上传处理

修复步骤 #

1. 修正settings.py配置 #

修改适配django-storages的配置规则，确保存储类能正确读取IBM COS的连接参数：

# IBM STORAGE CONFIG
IBM_API_KEY_ID = '你的实际IBM_API_KEY_ID'
IAM_SERVICE_ID = '你的实际IAM_SERVICE_ID'
ENDPOINT = 'https://s3.us-east.cloud-object-storage.appdomain.cloud'
IBM_AUTH_ENDPOINT = 'https://iam.bluemix.net/oidc/token'
IBM_STORAGE_BUCKET_NAME = 'cloud-object-storage-3u-cos-standard-77w'

# django-storages 适配配置
AWS_ACCESS_KEY_ID = IBM_API_KEY_ID
AWS_SECRET_ACCESS_KEY = '' # IBM COS使用IAM认证，无需填写传统S3密钥
AWS_STORAGE_BUCKET_NAME = IBM_STORAGE_BUCKET_NAME
AWS_S3_ENDPOINT_URL = ENDPOINT
AWS_S3_REGION_NAME = 'us-east'
AWS_S3_SIGNATURE_VERSION = 'oauth'
AWS_S3_CONFIG = {
    'ibm_api_key_id': IBM_API_KEY_ID,
    'ibm_service_instance_id': IAM_SERVICE_ID,
    'ibm_auth_endpoint': IBM_AUTH_ENDPOINT,
}

AWS_S3_FILE_OVERWRITE = False
AWS_DEFAULT_ACL = None
DEFAULT_FILE_STORAGE = 'storages.backends.s3boto3.S3Boto3Storage'

2. 简化视图逻辑（推荐方案） #

配置正确后，Django的FileField会自动调用默认存储将文件上传到IBM COS，同时自动把路径写入数据库，无需手动实现上传逻辑：

class upload_to_ibm_auto(LoginRequiredMixin, CreateView):
    model = Video
    context_object_name = 'Videos'
    form_class = VideoForm
    template_name = 'app_video/upload_to_ibm_auto.html'
    success_url = reverse_lazy('video_upload_local')

    def form_valid(self, form):
        form.instance.user = self.request.user
        # 如需自定义存储路径，可在此处修改form.instance.videofile的name属性
        return super().form_valid(form)

3. 保留自定义上传逻辑的修复方案 #

如果需要自己控制上传流程，需手动绑定上传后的路径，避免Django二次处理文件：

def form_valid(self, form):
    cos_client  = ibm_boto3.client(service_name='s3',
    ibm_api_key_id=settings.IBM_API_KEY_ID,
    ibm_service_instance_id=settings.IAM_SERVICE_ID,
    ibm_auth_endpoint=settings.IBM_AUTH_ENDPOINT,
    config=Config(signature_version='oauth'),
    endpoint_url=settings.ENDPOINT)
    
    upload_name = str(form.cleaned_data['videofilename'])
    # 直接读取表单文件流，无需存储到本地
    file_content = form.cleaned_data['videofile']
    userid = str(self.request.user.id)
    uploadtime = datetime.datetime.now().strftime('%Y%m%d%H%M%S')
    key = f"video/{userid}-{uploadtime}-{upload_name}"
    bucket = settings.IBM_STORAGE_BUCKET_NAME
    
    try:
        cos_client.upload_fileobj(Fileobj=file_content, Bucket=bucket, Key=key)
    except Exception as e:
        print(e)
        return super().form_invalid(form)
    
    # 手动绑定文件路径，清空表单文件对象
    form.instance.videofile = key
    form.cleaned_data.pop('videofile')
    form.instance.user = self.request.user
    
    return super().form_valid(form)

内容的提问来源于stack exchange，提问作者jablok1