(Node.js) (using AWS Signature Version 2) Streaming Download to File

The main purpose of this example is to demonstrate how to use the older Signature Version 2 authentication w/ S3. It uses V2 authentication to download a file.

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() {

    // 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 Amazon AWS REST server.
    var bTls = true;
    var port = 443;
    var bAutoReconnect = true;
    // The file is located in the bucket named "chilkat100", which becomes part of the domain:
    var success = rest.Connect("chilkat100.s3.amazonaws.com",port,bTls,bAutoReconnect);

    // Provide AWS credentials for the REST call.
    var authAws = new chilkat.AuthAws();
    authAws.AccessKey = "AWS_ACCESS_KEY";
    authAws.SecretKey = "AWS_SECRET_KEY";
    authAws.ServiceName = "s3";

    // For AWS Signature Version 2, the following two properties need to be set:
    authAws.SignatureVersion = 2;
    // See http://docs.aws.amazon.com/AmazonS3/latest/dev/RESTAuthentication.html#ConstructingTheCanonicalizedResourceElement
    authAws.CanonicalizedResourceV2 = "/chilkat100/starfish.jpg";

    success = rest.SetAuthAws(authAws);

    // Send the request to download the JPG.
    success = rest.SendReqNoBody("GET","/starfish.jpg");
    if (success !== true) {
        console.log(rest.LastErrorText);
        return;
    }

    // Read the response header.
    var responseStatusCode = rest.ReadResponseHeader();
    if (responseStatusCode < 0) {
        console.log(rest.LastErrorText);
        return;
    }

    console.log("Response status code = " + responseStatusCode);

    // We expect a 200 response status if the JPG data is coming.
    // Otherwise, we'll get a string response body with an error message(or no response body).
    if (responseStatusCode == 200) {

        var bodyStream = new chilkat.Stream();

        // The stream's sink will be a file.
        bodyStream.SinkFile = "qa_output/starfish.jpg";

        // Read the response body to the stream.  Given that we've
        // set the stream's sink to a file, it will stream directly
        // to the file.
        success = rest.ReadRespBodyStream(bodyStream,true);
        if (success !== true) {
            console.log(rest.LastErrorText);
            return;
        }

        console.log("Successfully received the JPG file.");

    }
    else {
        var errResponse = rest.ReadRespBodyString();
        if (rest.LastMethodSuccess !== true) {
            console.log(rest.LastErrorText);
        }
        else {
            console.log(errResponse);
        }

    }


}

chilkatExample();