grafana cannot properly connect to kairos-db

[razvanpaul-mielcioiu]

What happened:
I am creating a panel with kairos-db as datasource, then I notice this:

• metric names are not fetched the first time I open a new panel; I am able to bypass that by changing the visualization to the old graph panel, and then back to the time series (default) one; after this I can chose metrics, but the spinner for loading tags keep spinning; I need to do the trick with the changing the visualization to the old graph panel, and then back, and now I see the tags count.
• however, when I try to use tags to make a grouping in the query, the tags are not available as grouping options; I can see that there is a request to fetch tags from db, and that one works.

Another thing mentioning is that there is a javascript error when I first open the panel (kairos-db is set as default datasource):
PanelQueryRunner.ts:246 PanelQueryRunner Error TypeError: You provided 'undefined' where a stream was expected. You can provide an Observable, Promise, Array, or Iterable. at l (subscribeTo.js:28)

And there is another javascript error when tag count is displayed:
TypeError: Cannot read property 'length' of undefined at TagsSelectCtrl (tags_select.ts:11)

What you expected to happen:
I am expecting the metric names to be fetched smoothly, as well as tags and that I am able to select a metric name from the dedicated field and use a certain tag in a group-by rule.

How to reproduce it (as minimally and precisely as possible):

• kairos-db environment, with some metrics with tags
• fresh install of grafana 7.5.10, 8.1.0, 8.1.2 with default settings
• create a dashboard then a panel connecting to the kairos db datasource, and try to select a metric, and a group by a certain tag.

Anything else we need to know?:
I can create a panel with kairos as source, tags and everything if I use grafana 7.3.1, but I haven't tried with other 7.x versions except 7.5.10 where it doesn't work.

Environment:

• Grafana version: 7.5.10, 8.1.0, 8.1.2
• Data source type & version: kairos-db 1.1.1
• OS Grafana is installed on: docker container based on ubuntu:18.04
• User OS & Browser: Windows 10; Firefox 91.0.2, Chrome 92.0.4515.159
• Grafana plugins:
  grafana-image-renderer @ 2.0.0
  grafana-kairosdb-datasource @ 3.0.2

I opened this first with the grafana team, and they pointed that the issues is with the kairos-db datasource plugin implementation not using the latest pluginAPI from grafana.

[mckn]

@razvanpaul-mielcioiu I did some digging on who is maintaining this plugin and it is no longer maintained by the Grafana organization. We transfered the ownership to an external contributor who seems to removed their Github account.

So currently we don't have anyone maintaining this plugin. If anyone wants to take ownership of this we are happy to arrange that but I think this repository will be archived and the plugin marked as deprecated (for now).