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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))
  }
})
```

""" Helper class to run a shell command in a background thread. """
    def __init__(self, cmd, params={}, outfile=None, env_vars={}, stdin=False,
            quiet=True, inherit_cwd=False, inherit_env=True):
        self.cmd = cmd
        self.process = None
        self.outfile = outfile or os.devnull
        self.stdin = stdin
        self.env_vars = env_vars
        self.inherit_cwd = inherit_cwd
        self.inherit_env = inherit_env
        FuncThread.__init__(self, self.run_cmd, params, quiet=quiet)
    def run_cmd(self, params):
        def convert_line(line):
            line = to_str(line or '')
            return '%s\r\n' % line.strip()
        def filter_line(line):
            """ Return True if this line should be filtered, i.e., not printed """
            return '(Press CTRL+C to quit)' in line
        try:
            self.process = run(self.cmd, asynchronous=True, stdin=self.stdin, outfile=self.outfile,
                env_vars=self.env_vars, inherit_cwd=self.inherit_cwd, inherit_env=self.inherit_env)
            if self.outfile:
                if self.outfile == subprocess.PIPE:
                    
                    streams = ((self.process.stdout, sys.stdout), (self.process.stderr, sys.stderr))
                    for instream, outstream in streams:
                        for line in iter(instream.readline, None):