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# Type of request: This is a ...

[x ] bug report
[ ] feature request

# Detailed description

Not able to use the edge service to write metric data to cloudwatch via the javascript aws-sdk.

However, It **DOES** work when using the deprecated cloudwatch port.

## Expected behavior

Metric data to be visible when calling `awslocal cloudwatch list-metrics`

## Actual behavior

404 from edge service. No metric data is persisted, localstack instance logs the following info:

```
INFO:localstack.services.edge: Unable to determine forwarding port for API "monitoring" - please make sure this API is enabled via the SERVICES configuration
```

# Steps to reproduce

Run JS code in "Client code" section.
See 404 Error

## Command used to start LocalStack

`TMPDIR=/tmp/localstack docker-compose up`

## Client code (AWS SDK code snippet, or sequence of "awslocal" commands)

```js
const AWS = require('aws-sdk')
const cw = new AWS.CloudWatch({
  endpoint: 'http://localhost:4566',
})

const data = {
  Namespace: 'ns',
  MetricData: [
    {
      MetricName: 'metric-name',
      Timestamp: new Date(),
      Value: 12345,
      Unit: 'Milliseconds',
      Dimensions: [
        { Name: 'Environment', Value: 'local' },
      ]
    }
  ]
}

cw.putMetricData(data, (err, data) => {
  if (err) {
      console.log('Error', err)
  } else {
      console.log('Success', JSON.stringify(data))
  }
})
```

""" Convert message attribute details (first characters) to lower case (e.g., stringValue, dataType). """
    message_attrs = message_attrs or {}
    for _, attr in message_attrs.items():
        if not isinstance(attr, dict):
            continue
        for key, value in dict(attr).items():
            attr[first_char_to_lower(key)] = attr.pop(key)
    return message_attrs
def process_apigateway_invocation(func_arn, path, payload, stage, api_id, headers={},
                                  resource_path=None, method=None, path_params={},
                                  query_string_params=None, request_context={}):
    try:
        resource_path = resource_path or path
        path_params = dict(path_params)
        fix_proxy_path_params(path_params)
        event = {
            'path': path,
            'headers': dict(headers),
            'multiValueHeaders': multi_value_dict_for_list(headers),
            'pathParameters': path_params,
            'body': payload,
            'isBase64Encoded': False,
            'resource': resource_path,
            'httpMethod': method,
            'queryStringParameters': query_string_params,
            'multiValueQueryStringParameters': multi_value_dict_for_list(query_string_params),
            'requestContext': request_context,
            'stageVariables': get_stage_variables(api_id, stage),
        }
        return run_lambda(event=event, context={}, func_arn=func_arn,