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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))
  }
})
```

return jsonify({})
    mapping = delete_event_source(mapping_uuid)
    return jsonify(mapping)
@app.route('%s/functions/<function>/versions' % PATH_ROOT, methods=['POST'])
def publish_version(function):
    arn = func_arn(function)
    if arn not in arn_to_lambda:
        return not_found_error(arn)
    return jsonify(publish_new_function_version(arn))
@app.route('%s/functions/<function>/versions' % PATH_ROOT, methods=['GET'])
def list_versions(function):
    arn = func_arn(function)
    if arn not in arn_to_lambda:
        return not_found_error(arn)
    return jsonify({'Versions': do_list_versions(arn)})
@app.route('%s/functions/<function>/aliases' % PATH_ROOT, methods=['POST'])
def create_alias(function):
    arn = func_arn(function)
    if arn not in arn_to_lambda:
        return not_found_error(arn)
    data = json.loads(request.data)
    alias = data.get('Name')
    if alias in arn_to_lambda.get(arn).aliases:
        return error_response('Alias already exists: %s' % arn + ':' + alias, 404,
                              error_type='ResourceConflictException')
    version = data.get('FunctionVersion')
    description = data.get('Description')
    return jsonify(do_update_alias(arn, alias, version, description))
@app.route('%s/functions/<function>/aliases/<name>' % PATH_ROOT, methods=['PUT'])
def update_alias(function, name):