Question: How to actually use outbound blob binding in Azure Functions?

[ctolkien]

Here's the following blockers I've hit:

• Using async so cannot use out params
• Cannot return a Task<Stream> or Task<AnyMeaningfulCloudBlobTypes>, using $return binding. - Cannot bind parameter 'outputBlob' to type CloudBlockBlob. Make sure the parameter Type is supported by the binding. . All the documentation so far I've seen for this only return a Task<string> ?
• Cannot use a CloudBlockBlob as an out binding and use methods like UploadFromStreamAsync(...) to write to it - Cannot bind blob to CloudBlockBlob using access Write.
• CAN use a Stream or CloubBlobStream and then write to those streams - however, I have no way of setting the properties on the blob using these objects (for instance, I want to set the ContentType).

There appears to be no way of writing to a blob and setting properties using bindings? Do I have to drop down to directly using the .Net Azure storage api?

[fabiocav]

This lacks documentation, but in the integration tab, go to advanced and change the 'direction' of your blob binding to inout with that, you'll be able to bind to CloudBlockBlob and do what you need.

[mathewc]

Related to #49. We need to prioritize making this easier to use, I agree. This issue keeps falling onto the back burner.

[lindydonna]

Duplicate of #49, which is moved to an earlier milestone.

[nzigel]

How do you set the binding to inout if I am using the attributes in VS2017 preview and don't have a function.json file?

e.g. public static async Task Run([BlobTrigger("inputcontainer/{name}", Connection = "AzureWebJobsStorage")]CloudBlockBlob myBlob, [Blob("outputcontainer/{name}", Connection = "AzureWebJobsStorage")]CloudBlockBlob outputBlob, string name, TraceWriter log)

[lindydonna]

@nzigel In the future, please open a new issue so it's not lost.

That example should automatically use inout. If it doesn't, that's a bug .

[gabrielcerutti]

CloudBlockBlob output binding is not working for me? is this supported today?

[mathewc]

No there isn't an output binding to CloudBlockBlob. You could bind to CloudBlobContainer or CloudBlobDirectory and create blobs using the native SDK APIs.