ProxyGate

A proxy with lambda integrated function to consolidate and transit HTTP requests from {myProxy+} on API Gateway.

Environment Setup

$ cd path/to/project
$ pip install -r requirements.txt -t .

After implement to AWS lambda and integrated with API Gateway, setup os environment of server endpoint and configuration source.

$ aws lambda update-function-configuration --function-name ProxyGate \
    --environment "Variables={api_url=https://www.server.site ,resource=https://www.config.site}"

Configuration Data Structure

{
    "pathName": {
        "mapping": {
            "server_field1": "client_field1",
            "server_field2": "client_field2",
            "server_field3": "client_field3",
            "server_field4": "client_field4",
            "server_field5": "client_field5"
        },
        "constant": {
            "server_constant_field": "foo"
        },
        "condition": [
            {
                "if": {
                    "server_field1": [
                        "apple"
                    ]
                },
                "then": {
                    "server_field2": "red",
                    "server_field3": "fruit"
                }
            }
        ],
        "formatting": {
            "server_field6" : "lambda x : x['server_field3'] + '_' + x['server_field4']"
        }
    }
}

pathName

Wildcard value of {myProxy+} on API Gateway as a key to respective configuration.

mapping

To indicate the value in client request payload and transit into the defined key.

constant

Fixed key-value pair to append to the payload.

condition

Each if statement is bind to their then action, as long as the clause(s) in if are satisfied, the payload will be rendered according to the value in then.

formatting

Manipulate the payload by evaling the lambda expression.

Example

Input and Output

// POST request as input.
{
   "amount":"1000",
   "session_id":"b3ceaf8f58ad0f",
   "order_number":"0035454",
   "shop":"TEST_STORE",
   "datetime":"2021-08-03 20:32:04",
   "order_list":[
      {
         "product":{
            "product_name":"itemA",
            "product_type":"normal",
            "product_id":"23067710-aa3e",
            "product_amount":"200"
         }
      },
      {
         "product":{
            "product_name":"itemB",
            "product_type":"normal",
            "product_id":"23352710-d3fd",
            "product_amount":"300"
         }
      },
      {
         "product":{
            "product_name":"itemC",
            "product_type":"normal",
            "product_id":"23395710-cedd",
            "product_amount":"250"
         }
      },
      {
         "product":{
            "product_name":"itemD",
            "product_type":"normal",
            "product_id":"04b86690-4ca5",
            "product_amount":"250"
         }
      }
   ]
}

Configuration starts iterating with defined path and extracting.

// Multiple payloads as output.
{
    'order_number' : '0035454',
    'amount' :  '200',
    'product_id' : '23067710-aa3e',
    'datetime' : '2021-08-03 20:32:04',
    'session_id' : 'b3ceaf8f58ad0f'
    'type' : 'normal'
}
{
    'order_number' : '0035454',
    'amount' :  '300',
    'product_id' : '23352710-d3fd',
    'datetime' : '2021-08-03 20:32:04',
    'session_id' : 'b3ceaf8f58ad0f'
    'type' : 'normal'
}
{
    'order_number' : '0035454',
    'amount' :  '250',
    'product_id' : '23395710-cedd',
    'datetime' : '2021-08-03 20:32:04',
    'session_id' : 'b3ceaf8f58ad0f'
    'type' : 'normal'
}
{
    'order_number' : '0035454',
    'amount' :  '250',
    'product_id' : '04b86690-4ca5',
    'datetime' : '2021-08-03 20:32:04',
    'session_id' : 'b3ceaf8f58ad0f'
    'type' : 'normal'
}