Azure Cognitive token is denied with axios within Azure Functions

Question

• Goal: Develop an Azure Function that translates body text through a Translator Azure resource

• Issue: When I test this function locally by running npm run start and trigger my function with a HTTP POST and { "text": "こんにちは元気ですか？" } as the body, I have a 401 code. The function is not able to retrieve an access token from the API endpoint https://westeurope.api.cognitive.microsoft.com/sts/v1.0/issueToken

• Code:

module.exports = async function (context, req) {

    const axios = require("axios");
    const qs = require("qs");

    if (req.body && req.body.text) {   
        try {
            // CONSTANTS
            const TRANSLATOR_KEY = "<MY-TRANSLATOR-KEY>";
            const TRANSLATOR_API_VERSION = "3.0";
            const TRANSLATOR_FROM_LANG = "ja";
            const TRANSLATOR_TO_LANG = "en";
            const TRANSLATOR_ENDPOINT = `https://api.cognitive.microsofttranslator.com/translate?api-version=${TRANSLATOR_API_VERSION}&from=${TRANSLATOR_FROM_LANG}&to=${TRANSLATOR_TO_LANG}`;
            const TOKEN_URL = "https://westeurope.api.cognitive.microsoft.com/sts/v1.0/issueToken";
            const TEXT_TO_TRANSLATE = [{"Text": req.body.text}];    

            let tokenResponse = await axios.post(TOKEN_URL, {
                headers: {
                        "Ocp-Apim-Subscription-Key": TRANSLATOR_KEY
                    }
                }
            )
            let translationResponse = await axios.post(TRANSLATOR_ENDPOINT,
                TEXT_TO_TRANSLATE, {
                    headers: {
                        "Content-type": "application/json",
                        "Authorization": `Bearer ${tokenResponse}`
                    }
                }
            )
            console.log(translationResponse);
            let textTranslated = translationResponse[0].translations[0].text;
            context.res = {
                status: 200,
                body: {
                    "message": "Success!",
                    "res": textTranslated
                }
            }

        }
        catch (error) {
            console.log(error);
            context.res = {
                status: 400,
                body: "Error with Translator resource"
            }
        }
    } else {
        context.res = {
            status: 400,
            body: "This HTTP triggered function executed successfully. Pass a text in the request body!"
        }
    }
}

• Error: Here is the long error I receive with console.log(error) when testing my Azure function locally:

Host lock lease acquired by instance ID '0000000000000000000000009D5DC6ED'.
Executing 'Functions.textTranslation' (Reason='This function was programmatically called via the host APIs.', Id=bcf9ca1c-ea58-4282-acfe-d066167bd5a1)
Error: Request failed with status code 401
    at createError (C:\Users\Administrator\Desktop\AzureTranslate\node_modules\axios\lib\core\createError.js:16:15)
    at settle (C:\Users\Administrator\Desktop\AzureTranslate\node_modules\axios\lib\core\settle.js:17:12)
    at IncomingMessage.handleStreamEnd (C:\Users\Administrator\Desktop\AzureTranslate\node_modules\axios\lib\adapters\http.js:322:11)
    at IncomingMessage.emit (events.js:387:35)
    at endReadableNT (internal/streams/readable.js:1317:12)
    at processTicksAndRejections (internal/process/task_queues.js:82:21) {
  config: {
    transitional: {
      silentJSONParsing: true,
      forcedJSONParsing: true,
      clarifyTimeoutError: false
    },
    adapter: [Function: httpAdapter],
    transformRequest: ],
    transformResponse: ],
    timeout: 0,
    xsrfCookieName: 'XSRF-TOKEN',
    xsrfHeaderName: 'X-XSRF-TOKEN',
    maxContentLength: -1,
    maxBodyLength: -1,
    validateStatus: [Function: validateStatus],
    headers: {
      Accept: 'application/json, text/plain, */*',
      'Content-Type': 'application/json',
      'User-Agent': 'axios/0.26.1',
      'Content-Length': 76
    },
    method: 'post',
    url: 'https://westeurope.api.cognitive.microsoft.com/sts/v1.0/issueToken',
    data: '{"headers":{"Ocp-Apim-Subscription-Key":"<MY-TRANSLATOR-KEY>"}}'
  },
  request: <ref *1> ClientRequest {
    _events: {
      abort: [Function (anonymous)],
      aborted: [Function (anonymous)],
      connect: [Function (anonymous)],
      error: [Function (anonymous)],
Executed 'Functions.textTranslation' (Succeeded, Id=bcf9ca1c-ea58-4282-acfe-d066167bd5a1, Duration=689ms)
      socket: [Function (anonymous)],
      timeout: [Function (anonymous)],
      prefinish: [Function: requestOnPrefinish]
    },
    _eventsCount: 7,
    _maxListeners: undefined,
    outputData: [],
    outputSize: 0,
    writable: true,
    destroyed: false,
    _last: true,
    chunkedEncoding: false,
    shouldKeepAlive: false,
    _defaultKeepAlive: true,
    useChunkedEncodingByDefault: true,
    sendDate: false,
    _removedConnection: false,
    _removedContLen: false,
    _removedTE: false,
    _contentLength: null,
    _hasBody: true,
    _trailer: '',
    finished: true,
    _headerSent: true,
    socket: TLSSocket {
      _tlsOptions: [Object],
      _secureEstablished: true,
      _securePending: false,
      _newSessionPending: false,
      _controlReleased: true,
      secureConnecting: false,
      _SNICallback: null,
      servername: 'westeurope.api.cognitive.microsoft.com',
      alpnProtocol: false,
      authorized: true,
      authorizationError: null,
      encrypted: true,
      _events: [Object: null prototype],
      _eventsCount: 10,
      connecting: false,
      _hadError: false,
      _parent: null,
      _host: 'westeurope.api.cognitive.microsoft.com',
      _readableState: [ReadableState],
      _maxListeners: undefined,
      _writableState: [WritableState],
      allowHalfOpen: false,
      _sockname: null,
      _pendingData: null,
      _pendingEncoding: '',
      server: undefined,
      _server: null,
      ssl: [TLSWrap],
      _requestCert: true,
      _rejectUnauthorized: true,
      parser: null,
      _httpMessage: [Circular *1],
      [Symbol(res)]: [TLSWrap],
      [Symbol(verified)]: true,
      [Symbol(pendingSession)]: null,
      [Symbol(async_id_symbol)]: 17,
      [Symbol(kHandle)]: [TLSWrap],
      [Symbol(kSetNoDelay)]: false,
      [Symbol(lastWriteQueueSize)]: 0,
      [Symbol(timeout)]: null,
      [Symbol(kBuffer)]: null,
      [Symbol(kBufferCb)]: null,
      [Symbol(kBufferGen)]: null,
      [Symbol(kCapture)]: false,
      [Symbol(kBytesRead)]: 0,
      [Symbol(kBytesWritten)]: 0,
      [Symbol(connect-options)]: [Object],
      [Symbol(RequestTimeout)]: undefined
    },
    _header: 'POST /sts/v1.0/issueToken HTTP/1.1\r\n' +
      'Accept: application/json, text/plain, */*\r\n' +
      'Content-Type: application/json\r\n' +
      'User-Agent: axios/0.26.1\r\n' +
      'Content-Length: 76\r\n' +
      'Host: westeurope.api.cognitive.microsoft.com\r\n' +
      'Connection: close\r\n' +
      '\r\n',
    _keepAliveTimeout: 0,
    _onPendingData: [Function: noopPendingOutput],
    agent: Agent {
      _events: [Object: null prototype],
      _eventsCount: 2,
      _maxListeners: undefined,
      defaultPort: 443,
      protocol: 'https:',
      options: [Object],
      requests: {},
      sockets: [Object],
      freeSockets: {},
      keepAliveMsecs: 1000,
      keepAlive: false,
      maxSockets: Infinity,
      maxFreeSockets: 256,
      scheduling: 'lifo',
      maxTotalSockets: Infinity,
      totalSocketCount: 1,
      maxCachedSessions: 100,
      _sessionCache: [Object],
      [Symbol(kCapture)]: false
    },
    socketPath: undefined,
    method: 'POST',
    maxHeaderSize: undefined,
    insecureHTTPParser: undefined,
    path: '/sts/v1.0/issueToken',
    _ended: true,
    res: IncomingMessage {
      _readableState: [ReadableState],
      _events: [Object: null prototype],
      _eventsCount: 4,
      _maxListeners: undefined,
      socket: [TLSSocket],
      httpVersionMajor: 1,
      httpVersionMinor: 1,
      httpVersion: '1.1',
      complete: true,
      headers: [Object],
      rawHeaders: [Array],
      trailers: {},
      rawTrailers: [],
      aborted: false,
      upgrade: false,
      url: '',
      method: null,
      statusCode: 401,
      statusMessage: 'Access Denied',
      client: [TLSSocket],
      _consuming: false,
      _dumped: false,
      req: [Circular *1],
      responseUrl: 'https://westeurope.api.cognitive.microsoft.com/sts/v1.0/issueToken',
      redirects: [],
      [Symbol(kCapture)]: false,
      [Symbol(RequestTimeout)]: undefined
    },
    aborted: false,
    timeoutCb: null,
    upgradeOrConnect: false,
    parser: null,
    maxHeadersCount: null,
    reusedSocket: false,
    host: 'westeurope.api.cognitive.microsoft.com',
    protocol: 'https:',
    _redirectable: Writable {
      _writableState: [WritableState],
      _events: [Object: null prototype],
      _eventsCount: 3,
      _maxListeners: undefined,
      _options: [Object],
      _ended: true,
      _ending: true,
      _redirectCount: 0,
      _redirects: [],
      _requestBodyLength: 76,
      _requestBodyBuffers: [],
      _onNativeResponse: [Function (anonymous)],
      _currentRequest: [Circular *1],
      _currentUrl: 'https://westeurope.api.cognitive.microsoft.com/sts/v1.0/issueToken',
      [Symbol(kCapture)]: false
    },
    [Symbol(kCapture)]: false,
    [Symbol(kNeedDrain)]: false,
    [Symbol(corked)]: 0,
    {
      accept: [Array],
      'content-type': [Array],
      'user-agent': [Array],
      'content-length': [Array],
      host: [Array]
    }
  },
  response: {
    status: 401,
    statusText: 'Access Denied',
    headers: {
      'content-length': '225',
      'content-type': 'application/json',
      'apim-request-id': '28ba7434-91d7-4d2e-86aa-d08f661cf81c',
      'strict-transport-security': 'max-age=31536000; includeSubDomains; preload',
      'x-content-type-options': 'nosniff',
      'www-authenticate': 'AzureApiManagementKey realm="https://westeurope.api.cognitive.microsoft.com/sts/v1.0",name="Ocp-Apim-Subscription-Key",type="header"',
      date: 'Fri, 08 Apr 2022 13:37:56 GMT',
      connection: 'close'
    },
    config: {
      transitional: [Object],
      adapter: [Function: httpAdapter],
      transformRequest: [Array],
      transformResponse: [Array],
      timeout: 0,
      xsrfCookieName: 'XSRF-TOKEN',
      xsrfHeaderName: 'X-XSRF-TOKEN',
      maxContentLength: -1,
      maxBodyLength: -1,
      validateStatus: [Function: validateStatus],
      headers: [Object],
      method: 'post',
      url: 'https://westeurope.api.cognitive.microsoft.com/sts/v1.0/issueToken',
      data: '{"headers":{"Ocp-Apim-Subscription-Key":"<MY-TRANSLATOR-KEY>"}}'
    },
    request: <ref *1> ClientRequest {
      _events: [Object: null prototype],
      _eventsCount: 7,
      _maxListeners: undefined,
      outputData: [],
      outputSize: 0,
      writable: true,
      destroyed: false,
      _last: true,
      chunkedEncoding: false,
      shouldKeepAlive: false,
      _defaultKeepAlive: true,
      useChunkedEncodingByDefault: true,
      sendDate: false,
      _removedConnection: false,
      _removedContLen: false,
      _removedTE: false,
      _contentLength: null,
      _hasBody: true,
      _trailer: '',
      finished: true,
      _headerSent: true,
      socket: [TLSSocket],
      _header: 'POST /sts/v1.0/issueToken HTTP/1.1\r\n' +
        'Accept: application/json, text/plain, */*\r\n' +
        'Content-Type: application/json\r\n' +
        'User-Agent: axios/0.26.1\r\n' +
        'Content-Length: 76\r\n' +
        'Host: westeurope.api.cognitive.microsoft.com\r\n' +
        'Connection: close\r\n' +
        '\r\n',
      _keepAliveTimeout: 0,
      _onPendingData: [Function: noopPendingOutput],
      agent: [Agent],
      socketPath: undefined,
      method: 'POST',
      maxHeaderSize: undefined,
      insecureHTTPParser: undefined,
      path: '/sts/v1.0/issueToken',
      _ended: true,
      res: [IncomingMessage],
      aborted: false,
      timeoutCb: null,
      upgradeOrConnect: false,
      parser: null,
      maxHeadersCount: null,
      reusedSocket: false,
      host: 'westeurope.api.cognitive.microsoft.com',
      protocol: 'https:',
      _redirectable: [Writable],
      [Symbol(kCapture)]: false,
      [Symbol(kNeedDrain)]: false,
      [Symbol(corked)]: 0,
      [Symbol(kOutHeaders)]: [Object: null prototype]
    },
    data: { error: }
  },
  isAxiosError: true,
  toJSON: [Function: toJSON]
}

• Important note:
  1. It is not an encoding issue due to Japanese characters as I have the same issue by trying to translate English text to German
  2. Also not working when I deploy my Azure function to the cloud environment and test it online. It only returns a 200 OK code without any error.
  3. This process is perfectly working with Postman:
     • Retrieving the token with a HTTP POST request on https://westeurope.api.cognitive.microsoft.com/sts/v1.0/issueToken with my translator resource key in "Ocp-Apim-Subscription-Key" header.
     • Use this token in 'Authorization' header with a HTTP POST request on https://api.cognitive.microsofttranslator.com/translate?api-version=3.0&from=ja&to=en and with {"text": "こんにちは元気ですか？"} in body.
     • I got an HTTP code 200 and this answer:

[
 {
   "translations": [
     {
       "text": "hello, how are you?"
       "to": "en"
     }
   ]
 }
]

• Configuration:

  • Node: 14.17.3
  • npm: 6.14.13
  • Azure function: 3.0.X
  • Axios: 0.26.1

• Questions:

  1. Why is there different behaviors between Postman and Axios?
  2. Is it due to CORS policy?

Thank you in advance for your help on this topic!