When using Starlink func start is very slow and function endpoint returns 'endpoints_resolution_error: Endpoints cannot be resolved'

[oshihirii]

Steps to reproduce:

• Be connected to Starlink
• Create a local development environment for Azure Functions
• Create your functions
• Run func start
• Call a local function endpoint

Expected Behaviour:

Local function endpoints start quickly.

Calling a function endpoint runs my function code.

Actual Behaviour:

Local function endpoints start slowly.

Calling a function endpoint returns this error:

endpoints_resolution_error: Endpoints cannot be resolved

Workaround:

If I connect to a VPN and run func start, it starts quickly and calling the local function endpoints returns no errors.

I posted on the msal-node repo, as I thought it might be related to that library in particular:

AzureAD/microsoft-authentication-library-for-js#6684

When I remove the code that requests a token, i get a successful response.

As soon as I add the token request back, I get the error.

But perhaps it is an issue with azure-functions-core-tools.

Environment:

package.json:

{
  "name": "",
  "version": "1.0.0",
  "description": "",
  "main": "src/functions/*.js",
  "scripts": {
    "start": "func start",
    "test": "echo \"No tests yet...\""
  },
  "dependencies": {
    "@azure/functions": "^4.0.0-alpha.1",
    "@azure/msal-node": "^2.5.1",
    "axios": "^1.6.0",
    "pino": "^8.16.1"
  },
  "devDependencies": {
    "azure-functions-core-tools": "^4.x"
  }
}

host.json:

{
  "version": "2.0",
  "logging": {
    "applicationInsights": {
      "samplingSettings": {
        "isEnabled": true,
        "excludedTypes": "Request"
      }
    }
  },
  "extensionBundle": {
    "id": "Microsoft.Azure.Functions.ExtensionBundle",
    "version": "[4.*, 5.0.0)"
  }
}

Node.js:

$ node --version
v18.18.1

My function files generally have this structure:

// import libraries, eg:
import { app } from '@azure/functions';
import axios from 'axios';

// add some helper functions here

app.http('MyPOSTHttpTriggerFunction', {
    methods: ['POST'],  
    authLevel: 'function',
    handler: async (request, context) => {

   // get a token to make graph api requests   
   // call some helper functions
   // return a response 

}

I am using the Azure Functions v4 programming model, Node.js and ES6 style module syntax etc.

[khkh-ms]

It is very difficult to reproduce the issue. It appears to be related to specific ISP as you mentioned that you don't see the issue after connecting to the VPN.