Question

我一直在努力争取这一天。我正在直接测试Azure Blob存储上传并获得可怕的CORS问题。 "XMLHttpRequest cannot load https://tempodevelop.blob.core.windows.net/tmp/a4d8e867-f13e-343f-c6d3-a603…Ym0PlrBn%2BU/UzUs7QUhQw%3D&sv=2014-02-14&se=2016-10-12T17%3A59%3A26.638531. Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost:8000' is therefore not allowed access. The response had HTTP status code 403."

我已经尝试过的事情：

将CORS设置为所有主机：
尝试在本地和heroku上托管我的应用
确保我可以使用其他工具（Azure存储资源管理器）上传文件
将我的AccessPolicy配置为'rwdl'，我肯定会获得访问签名（在单元测试中验证）。

整个代码可在此处找到：https://github.com/mikebz/azureupload

但相关部分在这里，前端上传：

<script>

    /* 
     * not a true GUID, see here: http://stackoverflow.com/questions/105034/create-guid-uuid-in-javascript
     */ 
    function guid() {
        function s4() {
            return Math.floor((1 + Math.random()) * 0x10000)
            .toString(16)
            .substring(1);
        }
        return s4() + s4() + '-' + s4() + '-' + s4() + '-' +
            s4() + '-' + s4() + s4() + s4();
    }

    function startUpload() {   
        var fileName = guid();

        jQuery.getJSON("/formfileupload/signature/" + fileName , function(data) {
                console.log("got a signature: " + data.bloburl);
                uploadFile(data.bloburl, data.signature);
            })
            .fail(function(jqxhr, textStatus, error) {
                console.log( "error: " + textStatus + " - " + error );
            })
    }
    
    function uploadFile(bloburl, signature) {        
        var xhr = new XMLHttpRequest();
        fileData = document.getElementById('fileToUpload').files[0];
        xhr.open("PUT", bloburl + "?" + signature);
        xhr.setRequestHeader('x-ms-blob-type', 'BlockBlob');
        xhr.setRequestHeader('x-ms-blob-content-type', fileData.type);
        result = xhr.send(fileData);
    }
</script>

python中的签名生成代码在这里：

def generate_access_signature(self, filename):
    """
    calls the Azure Web service to generate a temporary access signature.
    """
    blob_service = BlobService(
        account_name=self.account_name, 
        account_key=self.account_key
    )

    expire_at = datetime.utcnow()
    expire_at = expire_at + timedelta(seconds = 30)
    access_policy = AccessPolicy(permission="rwdl", expiry=expire_at.isoformat())

    sas_token = blob_service.generate_shared_access_signature( 
        container_name="tmp",
        blob_name = filename, 
        shared_access_policy=SharedAccessPolicy(access_policy)
    )
    return sas_token

Answer 1

根据错误消息[响应具有HTTP状态代码403]，可能是服务未启用CORS，或者没有CORS规则与预检请求匹配。细节请参考Cross-Origin Resource Sharing (CORS) Support for the Azure Storage Services。或者可能是SAS签名不正确。请尝试进行问题排查

尝试在Blob服务下检查Azure门户上的CORS设置。因为还有其他服务，如表，队列，文件。
您还可以使用Azure explore工具生成SAS令牌

获取SAS并尝试使用生成的SAS对其进行调试

Answer 2

感谢Tom和Microsoft的支持，问题已得到解决解决方案部分＃1 - 确保使用Azure存储库for Python版本0.33或更高版本。

这是我的要求文件：

azure-common==1.1.4
azure-nspkg==1.0.0
azure-storage==0.33.0
cffi==1.8.3
cryptography==1.5.2
dj-database-url==0.4.1
Django==1.10.2
enum34==1.1.6
futures==3.0.5
gunicorn==19.6.0
idna==2.1
ipaddress==1.0.17
pep8==1.7.0
psycopg2==2.6.2
pyasn1==0.1.9
pycparser==2.16
python-dateutil==2.5.3
requests==2.11.1
six==1.10.0
whitenoise==3.2.2

第二个问题是生成签名。生成正确签名的代码在此处：

from azure.storage.blob import BlockBlobService, ContainerPermissions
from datetime import datetime, timedelta


class AzureUtils:

    def __init__(self, account_name, account_key):
        if account_name is None:
            raise ValueError("account_name should not be None")
        if account_key is None:
            raise ValueError("account_key should not be None")
        self.account_name = account_name
        self.account_key = account_key

    def generate_access_signature(self, filename):
        """
        calls the Azure Web service to generate a temporary access signature.
        """
        block_blob_service = BlockBlobService(
            account_name=self.account_name,
            account_key=self.account_key
        )

        expire_at = datetime.utcnow()
        expire_at = expire_at + timedelta(seconds=30)

        permissions = ContainerPermissions.READ | ContainerPermissions.WRITE | ContainerPermissions.DELETE | ContainerPermissions.LIST

        sas_token = block_blob_service.generate_container_shared_access_signature(
                "tmp",
                permission=permissions,
                expiry=expire_at
        )

        return sas_token

也可以在此处检索解决方案：https://github.com/mikebz/azureupload

上传到Azure Blob时，请求的资源上不存在“Access-Control-Allow-Origin”标头

2 个答案: