Add option to the Datadog scaler to use the Cluster Agent as proxy (#…

…5496)

* Add new Datadog External scaler to talk to the DCA

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Add ability to retrieve a metric value from the DCA

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Use datadogmetric naming convention

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Merge both Datadog scalers into one

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Add authMode to the TriggerAuthentication

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Add unit tests for Datadog scaler with Cluster Agent proxy

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Fix activation

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Add E2E tests for the Datadog scaler using the Cluster Agent proxy

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Fixes after rebase

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Rearrange Datadog tests

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Fix linting errors

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Keep token only auth

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Remove references to ca metadata

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* remove trailing space

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Add changelog entry for cluster agent as proxy feature

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Fix activation parameter for Datadog API

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Adjust Datadog test values

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Fix typo in Datadog test

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Make cluster agent metric server parameter mandatory

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Use only service name and namespace to resolve the Cluster Agent service IP

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

* Fix linting issues

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>

---------

Signed-off-by: Ara Pulido <ara.pulido@datadoghq.com>
Co-authored-by: Jorge Turrado Ferrero <Jorge_turrado@hotmail.es>

CHANGELOG.md

@@ -71,6 +71,7 @@ To learn more about active deprecations, we recommend checking [GitHub Discussio
 Here is an overview of all new **experimental** features:
 
 - TODO ([#XXX](https://github.com/kedacore/keda/issues/XXX))
+- **Datadog Scaler**: Add support to use the Cluster Agent as source of metrics ([#5355](https://github.com/kedacore/keda/issues/5355))
 
 ### Improvements