Chunk mixin is not deployed by default

[cyriltovena]

I created a new env with this:

  mixins+:: cortex_grafana_mixins {
    loki: loki_mixin,
    billing: billing_mixin,
  },

Turns out this is not enough to deploy a default configuration, I was expecting chunks mixin to be deployed. However this worked:

  mixins+:: cortex_grafana_mixins {
    loki: loki_mixin,
    billing: billing_mixin,
    cortex+: {
      _config+:: {
        storage_engine: ['chunks'], 
      },
    },
  },

I think by default we should deploy chunks mixin.

[pracucci]

I assumed it would have used these defaults:

cortex-jsonnet/cortex-mixin/config.libsonnet

Lines 5 to 9 in 56cb5e3

	_config+:: {
	// Switch for overall storage engine.
	// May contain 'chunks', 'tsdb' or both.
	// Enables chunks- or tsdb- specific panels and dashboards.
	storage_engine: ['chunks', 'tsdb'],

But I guess there's an issue somewhere.