Can't use ICloudBlob or CloudBlockBlob for output bindings

I’m trying to use ICloudBlob or CloudBlockBlob for blob output bindings. According to docs this should be supported.

I get the error:

Cannot bind blob to CloudBlockBlob using access Write

or

Cannot bind blob to ICloudBlob using access Write

My function is in F#, but I’ve tried C# as well and got the same error. Possibly related to this issue

Example C# repro:

#r "Microsoft.WindowsAzure.Storage"
using Microsoft.WindowsAzure.Storage.Blob;

public static void Run(Stream myBlob, string name, TraceWriter log, CloudBlockBlob outputBlob)
{
    log.Info($"C# Blob trigger function Processed blob\n Name:{name} \n Size: {myBlob.Length} Bytes");
}

{
  "bindings": [
    {
      "name": "myBlob",
      "type": "blobTrigger",
      "direction": "in",
      "path": "samples-workitems/{name}",
      "connection": "AzureWebJobsDashboard"
    },
    {
      "type": "blob",
      "name": "outputBlob",
      "path": "outcontainer/{rand-guid}",
      "connection": "AzureWebJobsDashboard",
      "direction": "out"
    }
  ],
  "disabled": false
}

[christopheranderson]

Workaround: If you set direction for the “outputBlob” binding to “inout”, this should be enabled. We’ll be working to make it easier to add inout via the UX to prevent these issues.

[nzigel]

@leolorenzoluis maybe the container name “x” is too short and you don’t have a markup for the blob name

[Blob(“outputcontainer/{name}”, FileAccess.ReadWrite, Connection = “AzureWebJobsStorage”)]CloudBlockBlob outputBlob

worked for me