MicroGateway ballerina filter getXmlPayload() removes the starting CRLF character from the first multipart boundary

[sajith-madhusanka]

Description

The CRLF characters at the beginning of the body are being removed when building the payload via the ballerina filter.

Steps to Reproduce

• Deploy a sample API in the microgateway.
• Configure the below as the endpoint of the sample API. http://localhost:8889 Setting up the backend.
• Create a file name docker-compose.yamllfile including the below code.

  version: "3.7"
  services:
  http-echo:        
  hostname: http-echo        
  image: mendhak/http-https-echo        
  environment:        
   - HTTP_PORT=8889        
  ports:
   - "8889:8889"

• Execute the below command inside the directory where the docker-compose.yaml file is stored. docker-compose up -d
• Execute the below command tp tail the logs of the backend server docker-compose logs -f - Add a custom filter to the microgateway project.
• Copy the following code to the soap_gdc_filter.bal file and place it inside the /extensions directory:

  
  import ballerina/http;
  import wso2/gateway;

xmlns "http://****" as gdc14;

string CONFIG_SOAP_GDCXML_CONTEXT = "usr_soap_gdcxml_context"; string CONFIG_ENVIRONMENT = "usr_environment"; string CONFIG_ENVIRONMENT_ID = "usr_environment_id";

string REQUEST_CONTENT_TYPE = "requestContentType"; string GDC_REQUEST_MESSAGE_ID = "gdcRequestMessageId"; string GDC_REQUEST_HEADER = "gdcRequestHeader";

string ERROR_RESPONSE_CODE = "error_response_code";

// Filter for the Soap GDC XML API // public type SoapGdcFilter object {

public function filterRequest(http:Caller caller, http:Request request, http:FilterContext context) returns boolean {

    if (context.attributes.hasKey(gateway:SKIP_ALL_FILTERS) && <boolean>context.attributes[gateway:SKIP_ALL_FILTERS]) {
        return true;
    }   

    xml|error payload = request.getXmlPayload();

    return true;
}

public function filterResponse(http:Response response, http:FilterContext context) returns boolean {
    return true;
}

}; // SoapGdcFilter

- Add the below configuration to the deployment-config.toml residing under the /conf directory:

[[filters]] name = "SoapGdcFilter" position = 1

- Configure SOAP UI to send a post request with MTOM enabled.

- Invoke the API using the SOAP UI and you will be able to observe that the **CRLF** ("/r/n" ) character is being missed in the first multipart boundary when sending the request to the backend server. Check the backend server's log.
`"body": "------=_Part_32_1103335936.1688648631996\r\nContent-Transfer-Encoding: 8bit\r\ncontent-type:
`- It should include the CRLF character as below,
`"body": "\r\n------=_Part_32_1103335936.1688648631996\r\nContent-Transfer-Encoding: 8bit\r\ncontent-type:
`

### Affected Component

APIM

### Version

wso2am-micro-gw-3.2.0

### Environment Details (with versions)

_No response_

### Relevant Log Output

_No response_

### Related Issues

_No response_

### Suggested Labels

_No response_

[npamudika]

Fixed with https://github.com/wso2/product-microgateway/pull/3402