Azure Blob List "Value for one of the query parameters specified in the request URI is invalid&-CodePudding

I'm using API Management service to make a simple interface between a c# desktop application and a Azure Blob storage account.

API Management service is providing the authentication via a Subscription Key. This works fine for downloading blobs.

I also want to list the contents of an individual container / folder (prefix) using the same method.

I've tested the following HTTP call outside the API Management service, it works correctly.

https://<account>.blob.core.windows.net/files?restype=directory&comp=list&prefix=globalpackages/1.0

When I use this in API Management service, I'm returned an error:

<Error>
    <Code>InvalidQueryParameterValue</Code>
    <Message>Value for one of the query parameters specified in the request URI is invalid.
RequestId:917b0aa8-101e-006b-0709-8e85b0000000
Time:2022-07-02T11:47:29.0834806Z</Message>
    <QueryParameterName>comp</QueryParameterName>
    <QueryParameterValue>list</QueryParameterValue>
    <Reason />
</Error>

My processing rules:

<policies>
    <inbound>
        <base />          
        <set-header name="Ocp-Apim-Subscription-Key" exists-action="delete" />
        <set-header name="Sec-Fetch-Site" exists-action="delete" />
        <set-header name="Sec-Fetch-Mode" exists-action="delete" />
        <set-header name="Sec-Fetch-Dest" exists-action="delete" />
        <set-header name="Accept" exists-action="delete" />
        <set-header name="Accept-Encoding" exists-action="delete" />
        <set-header name="Referer" exists-action="delete" />
        <set-header name="X-Forwarded-For" exists-action="delete" />
        <set-header name="x-ms-version" exists-action="override">
            <value>@{string version = "2017-11-09"; return version;}</value>
        </set-header>
        <set-backend-service base-url="@{
return String.Format("https://<storageaccount>.blob.core.windows.net/files?restype=directory&comp=list&prefix=globalpackages/1.0");
}" />
        <authentication-managed-identity resource="https://storage.azure.com/" />
    </inbound>
    <backend>
        <base />
    </backend>
    <outbound>
        <base />
    </outbound>
    <on-error>
        <base />
    </on-error>
</policies>

what am I doing wrong?

CodePudding user response：

Based on the documentation available here, the query parameter should be restype=container instead of restype=directory if you need to list blobs inside a blob container.

Once you make this change, you should be able to list the blobs.