// Alloy on db-primary / db-replica (design 4.1 / 4.3): postgres exporter (built-in collectors: pg_replication_lag_seconds,
// pg_up, pg_stat_*) + custom pg_is_wal_replay_paused -> Mimir; PostgreSQL logs -> Loki. instance = VM name.
prometheus.exporter.postgres "db" {
  data_source_names         = [sys.env("PG_DSN")]
  custom_queries_config_path = "/etc/alloy/queries.yaml"
  disable_settings_metrics  = true
}

prometheus.scrape "db" {
  job_name        = "postgres"
  scrape_interval = "15s"
  targets         = prometheus.exporter.postgres.db.targets
  forward_to      = [prometheus.relabel.instance.receiver]
}

prometheus.relabel "instance" {
  forward_to = [prometheus.remote_write.mimir.receiver]
  rule { target_label = "instance", replacement = sys.env("INSTANCE") }
}

prometheus.remote_write "mimir" {
  endpoint { url = "http://10.20.0.10:9009/api/v1/push" }
}

local.file_match "pglogs" {
  path_targets = [{ "__path__" = "/var/log/postgresql/*.log", "job" = "postgres", "instance" = sys.env("INSTANCE") }]
}

loki.source.file "pglogs" {
  targets    = local.file_match.pglogs.targets
  forward_to = [loki.write.loki.receiver]
}

loki.write "loki" {
  endpoint { url = "http://10.20.0.10:3100/loki/api/v1/push" }
}