Configuring loki file scraping to include various static & dynamic labels

Grafana Alloy
,
1

Hi,

hoping someone on here might be able to assist me.
I have setup an alloy service that is currently setup to scrape a load of application log directories and forward these various log files to Loki.

It more or less works, I have a
stage.regex: successfully finds the logs files and extracts the appname from the path
values: sets an app label to the extracted appname.

This seems to work, what I am trying to do is include a couple of semi-static labels for a couple of server based metrics.
e.g. Environment and Hostname.
I can confirm that on my Alloy service (Docker container) both the environment variables are set and return values but I cannot figure out how to get them into the log entries output in Loki.

I tried:
loki.process
…..
values = {
app = “appname”,
environment = sys.env(“ENVIRONMENT”)
}

this has no effect, although similar config does work for scraping docker logs.

Anyone got any ideas?

loki.source.file "apps" {
  targets    = local.file_match.apps.targets
  forward_to = [loki.process.apps.receiver]
  tail_from_end = true
}
loki.process "apps" {
  stage.regex {
    expression = `\/opt\/apps\/(?<appname>[^\/]+)\/logs\/.*`
    source     = "filename"
  }

  values = {
    app = "appname",
  }

  forward_to = [loki.write.main.receiver]
}

This works, but if I add in the environment tag into the values it does not get included in the entries.

Many thanks!

2

Hey take a look at stage.static_labels.