Prometheus Remote Write#

If you already run Prometheus, the simplest way to get its metrics into this stack is to have it remote-write to the gateway. Nothing needs to change about how that Prometheus discovers or scrapes its targets.

The gateway runs a prometheus.receive_http listener on port 9090, serving the standard remote-write path:

http://alloy-gateway.<namespace>.svc:9090/api/v1/metrics/write

Configuring the sender#

In prometheus.yml:

remote_write:
  - url: http://alloy-gateway.monitoring.svc:9090/api/v1/metrics/write

Any remote-write client works — a Prometheus server, Prometheus Agent, Grafana Alloy, or an OpenTelemetry Collector with the prometheusremotewrite exporter.

What happens after it arrives#

Received series are converted to OTLP by an internal bridge and join everything the gateway collects itself, so they get the same processing: enrichment, the importance tiers that decide which destinations each series reaches, and the egress filter.

That means remote-written metrics are subject to the same denylist and tiering as scraped ones. If a series you push is not appearing at a destination, check those before the transport.

Securing it#

The listener does not authenticate callers. Access control is NetworkPolicy, and TLS on this port is governed by pipeline.metrics.gateway.server.tls — a different value from the OTLP and Loki listeners. See the ingress overview.

See also#

• Overview — the four collection paths, and the ports they use.
• Storing — where the metrics go once they are in.
• OpenTelemetry Endpoint — the OTLP equivalent of this page.