<!-- 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))
  }
})
```

if line in [None, '', b'']:
                                break
                            if not (line and line.strip()) and self.is_killed():
                                break
                            line = convert_line(line)
                            if filter_line(line):
                                continue
                            outstream.write(line)
                            outstream.flush()
                self.process.wait()
            else:
                self.process.communicate()
        except Exception as e:
            if self.process and not self.quiet:
                LOG.warning('Shell command error "%s": %s' % (e, self.cmd))
        if self.process and not self.quiet and self.process.returncode != 0:
            LOG.warning('Shell command exit code "%s": %s' % (self.process.returncode, self.cmd))
    def is_killed(self):
        if not self.process:
            return True
        if INFRA_STOPPED:
            return True
        
        
        
        import psutil
        return not psutil.pid_exists(self.process.pid)
    def stop(self, quiet=False):