[feature] Adding configuration tab to tag the services through labels

[dmoreira97DLTT]

This PR aims to add the feature of adding a configuration tab to tag the services through labels. To achieve this functionality we added the needed values to all charts' values.yaml and values.schema.json, while also altering the _labels.tpl template in the library-chart. This lead us to the following solution:

These tags (labels) can later be used as filters in Prometheus queries, Grafana Dashboards, and/or Kubernetes command-line tool (kubectl).

The current code still has the library-chart links pointing to the published chart at my repo due to testing reasons and a few missing details, such as:

• The following charts do not get the labels specified in the configuration tab:
  • argo-cd
  • postgresql
  • argo-workflows
  • dask
  • redash
  • mongodb
  • kafka
  • fastai
  • elastic

We suspect that this behavior is a consequence of the fact that these charts have external charts as dependencies, which makes the templates unable to attribute labels. The solution should be to have the labels attributed according to the original chart's values.yaml, but this makes it impossible to use tpl functions to check whether the labels are nill or not. Some other flaws may unfold, so we were considering to let these charts with no tags (labels) configuration unless there's an easier way to solve this issue.

If there is, we would appreciate a few pointers on how to do it. If there's no need for such lengths, we would prepare the code for the possible approval of this PR.

[olevitt]

@fcomte @avouacr you will be interested in this :)

[fcomte]

It looks good to me except that the url of the library chart dependencies url is your repo and not us.