Grafana Alloy supports sending data via the Prometheus remote write protocol and OpenTelemetry Protocol (OTLP). Collecting metrics and forwarding them to VictoriaMetrics using Prometheus scraping and remote writing is more straightforward, but using OpenTelemetry enables more complex processing operations to occur before sending data to VictoriaMetrics.

The Alloy configuration file can be found in the following location depending on your platform:

  • Linux: /etc/alloy/config.alloy
  • Windows: %ProgramFiles%\GrafanaLabs\Alloy\config.alloy
  • MacOS: $(brew --prefix)/etc/alloy/config.alloy

To configure Grafana Alloy to push collected metrics to VictoriaMetrics via Prometheus remote write protocol, update the prometheus.remote_write endpoint:

prometheus.remote_write "victoriametrics" {
  endpoint {
    url = "https://<victoriametrics-addr>/prometheus/api/v1/write"
  }
}

For pushing data to VictoriaMetrics cluster the url should point to vminsert and include the tenantID:

https://<vminsert-addr>/insert/<tenant_id>/prometheus/api/v1/write

Note: read more about multitenancy or multitenancy via labels.

After the configuration has been updated, Alloy must be reloaded or restarted for the change to be applied:

  • Linux: sudo systemctl reload alloy.service
  • Windows: Restart-Service Alloy, this can also be done from the GUI using task manager
  • MacOS: brew services restart alloy
  • Helm chart: changing the alloy.configMap in the Alloy helm values

remote write #

In the example below we will be using the node exporter component built into Alloy to generate metrics, but any Prometheus scrape target can forward data to VictoriaMetrics. Metrics are forwarded from the scrape target to VictoriaMetrics by creating a prometheus.remote_write component and configuring the prometheus.scrape component to forward metrics to the prometheus.remote_write component.

prometheus.exporter.unix "nodeexporter" {}

prometheus.scrape "nodeexporter" {
  targets = prometheus.exporter.unix.nodeexporter.targets
  forward_to = [prometheus.remote_write.victoriametrics.receiver]
}

prometheus.remote_write "victoriametrics" {
  endpoint {
    url = "https://<victoriametrics-addr>/prometheus/api/v1/write"
  }
}

remote write with basic authentication #

This is the same as the previous configuration but adds the basic_auth parameters:

prometheus.exporter.unix "nodeexporter" {}

prometheus.scrape "nodeexporter" {
  targets = prometheus.exporter.unix.nodeexporter.targets
  forward_to = [prometheus.remote_write.victoriametrics.receiver]
}

prometheus.remote_write "victoriametrics" {
  endpoint {
    url = "https://<victoriametrics-addr>/prometheus/api/v1/write"
    basic_auth {
      username = "<victoriametrics_user>"
      password = "<victoriametrics_password>"
    }
  }
}

remote write with bearer authentication #

This is the same as the first config but adds the bearer_token parameter:

prometheus.exporter.unix "nodeexporter" {}

prometheus.scrape "nodeexporter" {
  targets = prometheus.exporter.unix.nodeexporter.targets
  forward_to = [prometheus.remote_write.victoriametrics.receiver]
}

prometheus.remote_write "victoriametrics" {
  endpoint {
    url = "https://<victoriametrics-addr>/prometheus/api/v1/write"
    bearer_token  = "<token>"
  }
}

OpenTelemetry #

prometheus.exporter.unix "nodeexporter" {}

prometheus.scrape "nodeexporter" {
  targets = prometheus.exporter.unix.nodeexporter.targets
  forward_to = [otelcol.receiver.prometheus.victoriametrics.receiver]
}

otelcol.receiver.prometheus "victoriametrics" {
  output {
    metrics = [otelcol.processor.batch.batch.input]
  }
}

otelcol.processor.batch "batch" {
  output {
    metrics = [otelcol.exporter.otlphttp.victoriametrics.input]
  }
}

otelcol.exporter.otlphttp "victoriametrics" {
  client {
    endpoint = "http://<victoriametrics-addr>:<victoriametrics_port>/opentelemetry"
  }
}

OpenTelemetry with Basic Authentication #

This is the same configuration without authentication but contains the otelcol.auth.basic block and references it in otelcol.exporter.otlphttp:

prometheus.exporter.unix "nodeexporter" {}

prometheus.scrape "nodeexporter" {
  targets = prometheus.exporter.unix.nodeexporter.targets
  forward_to = [otelcol.receiver.prometheus.victoriametrics.receiver]
}

otelcol.auth.basic "otel_auth" {
  username = "<user>"
  password = "<password>"
}

otelcol.receiver.prometheus "victoriametrics" {
  output {
    metrics = [otelcol.processor.batch.batch.input]
  }
}

otelcol.processor.batch "batch" {
  output {
    metrics = [otelcol.exporter.otlphttp.victoriametrics.input]
  }
}

otelcol.exporter.otlphttp "victoriametrics" {
  client {
    endpoint = "https://<victoriametrics-addr:<victoriametrics_port>/opentelemetry"
    auth = otelcol.auth.basic.otel_auth.handler
  }
}

OpenTelemetry with Bearer Authentication #

This is the same as the basic authentication configuration but swaps the otelcol.auth.basic for otelcol.auth.bearer:

prometheus.exporter.unix "nodeexporter" {}

prometheus.scrape "nodeexporter" {
  targets = prometheus.exporter.unix.nodeexporter.targets
  forward_to = [otelcol.receiver.prometheus.victoriametrics.receiver]
}

otelcol.auth.bearer "otel_auth" {
  token = "<token>"  
}

otelcol.receiver.prometheus "victoriametrics" {
  output {
    metrics = [otelcol.processor.batch.batch.input]
  }
}

otelcol.processor.batch "batch" {
  output {
    metrics = [otelcol.exporter.otlphttp.victoriametrics.input]
  }
}

otelcol.exporter.otlphttp "victoriametrics" {
  client {
    endpoint = "https://<victoriametrics-addr>:<victoriametrics_port>/opentelemetry"
    auth = otelcol.auth.bearer.otel_auth.handler
  }
}

References #