(Node.js) Azure Storage: CORS Preflight Blob Request

Azure Storage Blob Service REST API: Sample code to send a CORS pre-flight blob request.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

    // Azure Blob Service Example: CORS Preflight Blob Request
    // See also: https://msdn.microsoft.com/en-us/library/azure/dn535599.aspx

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    var rest = new chilkat.Rest();

    // Connect to the Azure Storage Blob Service
    var bTls = true;
    var port = 443;
    var bAutoReconnect = true;
    // In this example, the storage account name is "chilkat".
    var success = rest.Connect("chilkat.blob.core.windows.net",port,bTls,bAutoReconnect);
    if (success !== true) {
        console.log(rest.LastErrorText);
        return;
    }

    // Provide Azure Cloud credentials for the REST call.
    var azAuth = new chilkat.AuthAzureStorage();
    azAuth.AccessKey = "AZURE_ACCESS_KEY";
    // The account name used here should match the 1st part of the domain passed in the call to Connect (above).
    azAuth.Account = "chilkat";
    azAuth.Scheme = "SharedKey";
    azAuth.Service = "Blob";
    // This causes the "x-ms-version: 2021-08-06" header to be automatically added.
    azAuth.XMsVersion = "2021-08-06";
    success = rest.SetAuthAzureStorage(azAuth);

    // Note: The application does not need to explicitly set the following
    // headers: x-ms-date, Authorization.  These headers
    // are automatically set by Chilkat.

    // The preflight blob request requires the following two HTTP headers.
    // The Origin is the domain from which the actual request will be issued.
    success = rest.AddHeader("Origin","www.contoso.com");
    // The Access-Control-Request-Method is the HTTP method (such as GET, POST, PUT, etc.) of the actual request.
    success = rest.AddHeader("Access-Control-Request-Method","PUT");

    // The expected response is a 202 response status code with no response body.
    // The name of the container or blob resource in this example is "test". (Replace "test" with your container name.)
    var responseStr = rest.FullRequestNoBody("OPTIONS","/test");
    if (rest.LastMethodSuccess !== true) {
        console.log(rest.LastErrorText);
        return;
    }

    // When successful, the Azure Storage service will respond with a 200 response code,
    // with no response body.

    // If CORS is not enabled or no matching rule is found for the request, 
    // then a 403 status code is returned, with the following status text:
    // "CORS not enabled or no matching rule found for this request."
    if (rest.ResponseStatusCode !== 200) {
        // Examine the request/response to see what happened.
        console.log("response status code = " + rest.ResponseStatusCode);
        console.log("response status text = " + rest.ResponseStatusText);
        console.log("response header: " + rest.ResponseHeader);
        console.log("response body (if any): " + responseStr);
        console.log("---");
        console.log("LastRequestStartLine: " + rest.LastRequestStartLine);
        console.log("LastRequestHeader: " + rest.LastRequestHeader);
        return;
    }

    console.log("Success: Preflight Blob Request is accepted.");

}

chilkatExample();