<!-- Love localstack? Please consider supporting our collective:
👉  https://opencollective.com/localstack/donate -->

# 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))
  }
})
```

AttributeNames=['MessageRetentionPeriod', 'RedrivePolicy']
        )
        supported_attribute_get = self.client.get_queue_attributes(QueueUrl=queue_url,
                                                                   AttributeNames=['QueueArn'])
        
        self.assertTrue('MessageRetentionPeriod' in unsupported_attribute_get['Attributes'].keys())
        self.assertEqual('604800', unsupported_attribute_get['Attributes']['MessageRetentionPeriod'])
        self.assertTrue('QueueArn' in supported_attribute_get['Attributes'].keys())
        self.assertTrue('RedrivePolicy' in unsupported_attribute_get['Attributes'].keys())
        redrive_policy = json.loads(unsupported_attribute_get['Attributes']['RedrivePolicy'])
        self.assertTrue(isinstance(redrive_policy['maxReceiveCount'], int))
        
        self.client.delete_queue(QueueUrl=queue_url)
        self.client.delete_queue(QueueUrl=dead_queue_url)
    def test_set_unsupported_attributes(self):
        queue_name = 'queue-%s' % short_uid()
        queue_url = self.client.create_queue(QueueName=queue_name)['QueueUrl']
        self.client.set_queue_attributes(
            QueueUrl=queue_url,
            Attributes={
                'FifoQueue': 'true'
            }
        )
        rs = self.client.get_queue_attributes(QueueUrl=queue_url, AttributeNames=['All'])
        self.assertEqual(rs['ResponseMetadata']['HTTPStatusCode'], 200)
        self.assertIn('FifoQueue', rs['Attributes'])
        self.assertEqual(rs['Attributes']['FifoQueue'], 'true')
        
        self.client.delete_queue(QueueUrl=queue_url)
    def test_list_dead_letter_source_queues(self):