add loki cluster tags to promtail

Package Merge Request

Package Changes

Right now, all of the Loki logs that are shipped to Loki from promtail don't contain the "cluster" tag making selfMonitoring dashboards useless.

We add a rewrite in promtail to add the "cluster=" label to logs generated by Loki pods before being shipped to Loki storage.

Package MR

None

For Issue

Closes issue

Upgrade Notices

N/A