DocumentClient binding in parameter of Azure function

Question

I am writing an http trigger Azure function in F# and I would like to bind a parameter of type DocumentClient to have more control on the queries that are done in Cosmos DB. This is what I have so far:

Function.fs

namespace Functions

open System
open System.Net
open System.Net.Http
open Newtonsoft.Json
open Microsoft.Azure.Documents
open Microsoft.Azure.Documents.Client
open Microsoft.Azure.WebJobs
open Microsoft.Azure.WebJobs.Host
open Microsoft.Azure.WebJobs.Extensions
open Microsoft.Azure.WebJobs.Extensions.DocumentDB

module Function = 
  let Run(req: HttpRequestMessage, [<DocumentDB>] client: DocumentClient, log: TraceWriter) =
    log.Info(sprintf "F# HTTP trigger function processed a request.")
    req.CreateResponse(HttpStatusCode.OK)

function.json

{
  "disabled": false,
  "scriptFile": "..\\..\\..\\build\\Debug\\Functions\\Functions.dll",
  "entryPoint": "Functions.Function.Run",
  "bindings": [
    {
      "direction": "in",
      "type": "httpTrigger",
      "authLevel": "anonymous",
      "name": "req",
      "methods": [ "get" ],
      "route": "users"
    },
    {
      "direction": "in",
      "type": "documentDB",
      "name": "client",
      "connection": "COSMOSDB_CONNECTION_STRING"
    },
    {
      "direction": "out",
      "type": "http",
      "name": "res"
    }
  ]
}

host.json

{
  "frameworks": {
    "net46":{
      "dependencies": {
        "Dynamitey": "1.0.2",
        "FSharp.Interop.Dynamic": "3.0.0",
        "Microsoft.Azure.DocumentDB": "1.17.0",
        "Microsoft.Azure.WebJobs.Extensions.DocumentDB": "1.0.0"
      }
    }
  }
}

local.settings.json

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsDashboard": "",
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "COSMOSDB_CONNECTION_STRING": "AccountEndpoint=https://localhost:8081;AccountKey=C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==;"
  }
}

I am runnning the function locally using the development storage and Cosmos DB emulator. I tried to translate to F# what it is described here for C#. And it is also pretty much the same as what is mentioned here. But I only get the error Microsoft.Azure.WebJobs.Extensions.DocumentDB: 'Id' is required when binding to a DocumentClient property.

Answer 1

There is a workaround mentioned in this issue on Github. It's fixed in the tooling and will be available with the next release

workaround copied from github

I found the issue and filed https://github.com/Azure/azure-functions-cli/issues/206. The easiest workaround until we have an update:

Go to C:\Users\{user}\appdata\local\Azure.Functions.Cli\1.0.0.

Open func.exe.config in notepad.

Find this:

<dependentAssembly>
  <assemblyIdentity name="Microsoft.Azure.Documents.Client" publicKeyToken="31bf3856ad364e35" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-1.11.0.0" newVersion="1.11.0.0" />
</dependentAssembly>

In both places, replace 1.11.0.0 with 1.13.0.0 so you end up with:

<dependentAssembly>
    <assemblyIdentity name="Microsoft.Azure.Documents.Client" publicKeyToken="31bf3856ad364e35" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-1.13.0.0" newVersion="1.13.0.0" />
  </dependentAssembly>

Save and retry.