When I am running azure HTTP Trigger function i am getting 401 unauthorized

Question

I am trying to run Azure HTTP Trigger Azure Function and I am receiving a 401 Unauthorized. It was working fine for me earlier.

When I created the new function under the same Function App and copied the same code then also it is running fine but when I am trying to run my created function then I am getting the same error that I mentioned.

I'm seeing the following logs in the streaming service.

2018-07-02T07:09:41 Welcome, you are now connected to log-streaming service.

2018-07-02T07:09:48.893 [Info] Executing HTTP request: { "requestId": "53e54698-c46b-4cb6-9ed0-d042eaf9ec71", "method": "POST", "uri": "/api/Source/MPAA/false" }

2018-07-02T07:09:48.893 [Info] Executed HTTP request: { "requestId": "53e54698-c46b-4cb6-9ed0-d042eaf9ec71", "method": "POST", "uri": "/api/Source/MPAA/false", "authorizationLevel": "Anonymous", "status": "Unauthorized" }

Answer 1

This is how I solved the problem based on the cause correctly provided by Nick above. Do this if you don't want to have to open the Azure Function's GUI every time you push your code.

In the source code of the function:

[FunctionName("YourFunctionName")]
public static async Task<IActionResult> Run(
    [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
    ILogger log){

What I had to do was to change the default setting AuthorizationLevel.Function into AuthorizationLevel.Anonymous. The former only allows triggering from other Function apps, the later will let you trigger from the browser.

Answer 2

If you are managing your code via the azure portal, then simply navigate to "Integrate" and change the "Authorization Level" drop-down to "Anonymous".

If you are managing your code with source control integration (e.g. via git), add this to your function.json:

"authLevel": "anonymous"

Full snippet of function.json:

{
  "bindings": [
    {
      "name": "req",
      "type": "httpTrigger",
      "direction": "in",
      "methods": [ "post" ],
      "route": "Source/MPAA",
      "authLevel": "anonymous"
    },
    {
      "type": "http",
      "name": "res",
      "direction": "out"
    }
  ],
  "disabled": false
}

Note: the above is just an example, you may have to tweak the route. Note: the /api is the default prefix, and can be modified in the host.json file.

Answer 3

Its about the authlevel of the function. If you use the authlevel = anonymous in you function.json file. Then you don't have to pass any access key and you can access the azure function api like the normal api endpoints.

{
"disabled": false,    
"bindings": [
    {
        "authLevel": "anonymous",
        "type": "httpTrigger",
        "direction": "in",
        "name": "req"
    },
    {
        "type": "http",
        "direction": "out",
        "name": "res"
    }
]

}

For example you http trigger is http://<APP_NAME>.azurewebsites.net/api/<FUNCTION_NAME> you can easily access this without any access/auth key.

If your are using the authlevel = function then you have to pass the access key/Api key with the http trigger endpoint while hitting it. If you don't you will get the 401 unauthorized.

    {
"disabled": false,    
"bindings": [
    {
        "authLevel": "function",
        "type": "httpTrigger",
        "direction": "in",
        "name": "req"
    },
    {
        "type": "http",
        "direction": "out",
        "name": "res"
    }
]

}

You need to pass the key like as below example. **https://<APP_NAME>.azurewebsites.net/api/<FUNCTION_NAME>?code=<API_KEY> **

For the authlevel = function you can access the http trigger by the function key and the host key. You will find the Get Function Url section when you open the function in the azure portal.

Note With the host key you can access all of your http trigger endpoints its going to be common for all the http trigger. But the function key is unique for every function.

The third option is to use the authlevel = admin.

{
"disabled": false,    
"bindings": [
    {
        "authLevel": "admin",
        "type": "httpTrigger",
        "direction": "in",
        "name": "req"
    },
    {
        "type": "http",
        "direction": "out",
        "name": "res"
    }
]

}

For auth level admin the http trigger can only be access by the master key. **https://<APP_NAME>.azurewebsites.net/api/<FUNCTION_NAME>?code=<MASTER_KEY> **

You will find all these keys as per the auth levels in the Get Function Url section. The complete guide for the authlevel is in this link. Azure Functions HTTP trigger function authlevel Explanation

I hope this will be helpfull.

Answer 4

I started getting 401's too until I realised that I had two functions with the same route. That obviously confused Azure big time.

Check if you don't have different functions with same routes.