Pascal (Lazarus/Delphi)

S3 Get Bucket Policy

See more Amazon S3 (new) Examples

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.

Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.AuthAws,
  Chilkat.Rest,
  Chilkat.JsonObject;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  rest: TRest;
  bTls: Boolean;
  port: Integer;
  bAutoReconnect: Boolean;
  authAws: TAuthAws;
  responseJsonStr: string;
  json: TJsonObject;

begin
  success := False;

  //  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 := TRest.Create;

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

  //  Provide AWS credentials.
  authAws := TAuthAws.Create;
  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);

  //  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 <> True) then
    begin
      WriteLn(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.
      WriteLn('response status code = ' + rest.ResponseStatusCode);
      WriteLn('response status text = ' + rest.ResponseStatusText);
      WriteLn('response header: ' + rest.ResponseHeader);
      WriteLn('response body: ' + responseJsonStr);
      WriteLn('---');
      WriteLn('LastRequestStartLine: ' + rest.LastRequestStartLine);
      WriteLn('LastRequestHeader: ' + rest.LastRequestHeader);
    end;

  WriteLn('response body: ' + responseJsonStr);

  //  Load the JSON and display in a more human-readable manner:
  json := TJsonObject.Create;
  json.Load(responseJsonStr);
  json.EmitCompact := False;
  WriteLn(json.Emit());

  //  Sample output:

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


  rest.Free;
  authAws.Free;
  json.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.