(Delphi ActiveX) S3 Get Bucket Policy

Demonstrates how to send a GET request to fetch the policy of a specified bucket. The following information is quoted from the AWS REST API reference documentation at http://docs.aws.amazon.com/AmazonS3/latest/API/RESTBucketGETpolicy.html

To use this operation, you must have GetPolicy permissions on the specified bucket, and you must be the bucket owner.

If you don't have GetPolicy permissions, Amazon S3 returns a 403 Access Denied error. If you have the correct permissions, but you're not the bucket owner, Amazon S3 returns a 405 Method Not Allowed error. If the bucket does not have a policy, Amazon S3 returns a 404 Policy Not found error. There are restrictions about who can create bucket policies and which objects in a bucket they can apply to. For more information, go to Using Bucket Policies.

Important: This example requires Chilkat v9.5.0.66 or greater.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
rest: TChilkatRest;
bTls: Integer;
port: Integer;
bAutoReconnect: Integer;
success: Integer;
authAws: TChilkatAuthAws;
responseJsonStr: WideString;
json: TChilkatJsonObject;

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

// Important: This example requires Chilkat v9.5.0.66 or greater.

rest := TChilkatRest.Create(Self);

// Connect to the Amazon AWS REST server in the desired region.
bTls := 1;
port := 443;
bAutoReconnect := 1;
success := rest.Connect('s3-us-west-2.amazonaws.com',port,bTls,bAutoReconnect);

// Provide AWS credentials.
authAws := TChilkatAuthAws.Create(Self);
authAws.AccessKey := 'AWS_ACCESS_KEY';
authAws.SecretKey := 'AWS_SECRET_KEY';
authAws.ServiceName := 's3';

// This particular bucket is in the Oregon region, as opposed to the US Standard,
// therefore the Region must be set appropriately.
// Also note that we connected to "s3-us-west-2.amazonaws.com".
authAws.Region := 'us-west-2';

success := rest.SetAuthAws(authAws.ControlInterface);

// Note: The above REST connection and setup of the AWS credentials
// can be done once.  After connecting, any number of REST calls can be made.
// The "auto reconnect" property passed to rest.Connect indicates that if
// the connection is lost, a REST method call will automatically reconnect
// if needed.
// --------------------------------------------------------------------------

// Set the bucket name via the HOST header.
// In this case, the bucket name is "chilkat.ocean".
// Note that the Host header should use "bucketName.s3.amazonaws.com", not "bucketName.s3-us-west-2.amazonaws.com"
rest.Host := 'chilkat.ocean.s3.amazonaws.com';

// Get the policy.
responseJsonStr := rest.FullRequestNoBody('GET','/?policy');
if (rest.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

// When successful, the S3 Storage service will respond with a 200 response code,
// with an XML body.  
if (rest.ResponseStatusCode <> 200) then
  begin
    // Examine the request/response to see what happened.
    Memo1.Lines.Add('response status code = ' + IntToStr(rest.ResponseStatusCode));
    Memo1.Lines.Add('response status text = ' + rest.ResponseStatusText);
    Memo1.Lines.Add('response header: ' + rest.ResponseHeader);
    Memo1.Lines.Add('response body: ' + responseJsonStr);
    Memo1.Lines.Add('---');
    Memo1.Lines.Add('LastRequestStartLine: ' + rest.LastRequestStartLine);
    Memo1.Lines.Add('LastRequestHeader: ' + rest.LastRequestHeader);
  end;

Memo1.Lines.Add('response body: ' + responseJsonStr);

// Load the JSON and display in a more human-readable manner:
json := TChilkatJsonObject.Create(Self);
json.Load(responseJsonStr);
json.EmitCompact := 0;
Memo1.Lines.Add(json.Emit());

// Sample output:

// 	{ 
// 	  "Version": "2012-10-17",
// 	  "Statement": [
// 	    { 
// 	      "Effect": "Allow",
// 	      "Resource": "arn:aws:s3.asp">chilkat.ocean/",
// 	      "Principal": "*"
// 	    }
// 	  ]
// 	}
// 
end;