How can I resolve an unauthorized error when using Azure Management API?

Question

Note: I would prefer to resolve this programmatically (in code) instead of running commands/scripts.

Objective:

I need to retrieve function names from a Function App in Azure.

Example:

  var current        = Pulumi.Azure.Core.GetClientConfig.InvokeAsync().Result;
  var subscriptionId = current.SubscriptionId;
  var appName        = functionApp.Name;

  var url = $"GET https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.Web/sites/{appName}/functions?api-version=2022-03-01";

  var httpClient = new HttpClient();
  var result     = await httpClient.GetAsync(url);

  if (!result.IsSuccessStatusCode) throw new Exception($"Error: Failed to retrive Azure function names from {appName}");

  var json = result.Content.ReadAsStringAsync();

Thoughts:

I think I need to create a bearer token but do not know the steps required.

This may help, Authenticate using a Service Principal, pulumi.com/registry/packages/azure-native/… — mzm
– mzm, Commented Dec 27, 2022 at 2:40

Sridevi · Accepted Answer · 2022-12-27 05:41:53Z

2

I tried to reproduce the same in my environment via Postman and got same error as below:

GET https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.Web/sites/{appName}/functions?api-version=2022-03-01

enter image description here

To resolve the error, you need to generate bearer token for the service principal and include it in headers section with Authorization parameter.

I registered one Azure AD application in my tenant like this: Go to Azure Portal -> Azure Active Directory -> App registrations -> New registration

enter image description here

Now, create one client secret in that application and copy its value like below:

enter image description here

Make sure to assign proper role based on your requirement. I assigned Reader role to the above service principal under my subscription like below:

Go to Azure Portal -> Subscriptions -> Your Subscription -> Access control (IAM) -> Add role assignment

enter image description here

In my function app, I created one HTTP function named SriHTTP like below:

enter image description here

Now, I generated access token via Postman with below parameters:

POST https://login.microsoftonline.com/<tenantID>/oauth2/v2.0/token

grant_type:client_credentials
client_id: <appID>
client_secret: <secret_value>
scope: https://management.azure.com/.default

Response:

enter image description here

I got the results successfully when I used the above token to call management API like below:

GET https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.Web/sites/{appName}/functions?api-version=2022-03-01
Authorization: Bearer <token>

Response:

enter image description here

answered Dec 27, 2022 at 5:41

Sridevi

23.6k1 gold badge11 silver badges30 bronze badges

Sign up to request clarification or add additional context in comments.

7 Comments

Scott Nimrod Over a year ago

Thanks for the detailed answer. I receive a gran_type error when attempting to post using PostMan. What authorization type do I use in PostMan on the Authorization tab?

Sridevi Over a year ago

Are you getting that grant_type error while acquiring token? Can you include the snip of Postman once to know what exactly the issue is?

Scott Nimrod Over a year ago

{ "error": "invalid_request", "error_description": "AADSTS900144: The request body must contain the following parameter: 'grant_type'.\r\nTrace ID: some_guid\r\nCorrelation ID: some_guid\r\nTimestamp: 2022-12-28 12:00:17Z", "error_codes": [ 900144 ],

Scott Nimrod Over a year ago

I assign the value "client_credentials" to grant_type.

Sridevi Over a year ago

If you are passing the parameters under Params or any, instead of Body section, you may get error like this.

|

Collectives™ on Stack Overflow

How can I resolve an unauthorized error when using Azure Management API?

1 Answer 1

7 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

7 Comments

Your Answer

Sign up or log in

Post as a guest

Related