otelcol.receiver.prometheus
otelcol.receiver.prometheus receives Prometheus metrics, converts them to the OpenTelemetry metrics format, and forwards them to other otelcol.* components.
This is a custom component built on a fork of the upstream OpenTelemetry Collector receiver.
You can specify multiple otelcol.receiver.prometheus components by giving them different labels.
Note
Support for translating Prometheus native histograms into OTLP exponential histograms is a public preview feature. To enable native histogram translation, run Alloy with the
--stability.level=public-previewconfiguration flag.
Usage
otelcol.receiver.prometheus "<LABEL>" {
output {
metrics = [...]
}
}Arguments
The otelcol.receiver.prometheus component doesn’t support any arguments. You can configure this component with blocks.
Note
otelcol.receiver.prometheuswill translate Prometheus native histograms into OTLP exponential histograms if Alloy is ran with the--stability.level=experimentalconfiguration flag.
Blocks
You can use the following blocks with otelcol.receiver.prometheus:
output
RequiredThe output block configures a set of components to forward resulting telemetry data to.
The following arguments are supported:
You must specify the output block, but all its arguments are optional.
By default, telemetry data is dropped.
Configure the metrics, logs, and traces arguments accordingly to send telemetry data to other components.
debug_metrics
The debug_metrics block configures the metrics that this component generates to monitor its state.
The following arguments are supported:
disable_high_cardinality_metrics is the Alloy equivalent to the telemetry.disableHighCardinalityMetrics feature gate in the OpenTelemetry Collector.
It removes attributes that could cause high cardinality metrics.
For example, attributes with IP addresses and port numbers in metrics about HTTP and gRPC connections are removed.
Note
If configured,
disable_high_cardinality_metricsonly applies tootelcol.exporter.*andotelcol.receiver.*components.
Exported fields
This component exports the following fields that other components can reference:
Component health
otelcol.receiver.prometheus is only reported as unhealthy if given an invalid configuration.
Debug information
otelcol.receiver.prometheus doesn’t expose any component-specific debug information.
Example
This example uses the otelcol.receiver.prometheus component as a bridge between the Prometheus and OpenTelemetry ecosystems.
The component exposes a receiver which the prometheus.scrape component uses to send Prometheus metric data to.
The receiver converts the metrics to OTLP format and forwards them to the otelcol.exporter.otlp component, which sends them to an OTLP-capable endpoint:
prometheus.scrape "default" {
// Collect metrics from the default HTTP listen address.
targets = [{"__address__" = "127.0.0.1:12345"}]
forward_to = [otelcol.receiver.prometheus.default.receiver]
}
otelcol.receiver.prometheus "default" {
output {
metrics = [otelcol.exporter.otlp.default.input]
}
}
otelcol.exporter.otlp "default" {
client {
endpoint = sys.env("OTLP_ENDPOINT")
}
}Compatible components
otelcol.receiver.prometheus can accept arguments from the following components:
- Components that export OpenTelemetry
otelcol.Consumer
otelcol.receiver.prometheus has exports that can be consumed by the following components:
- Components that consume Prometheus
MetricsReceiver
Note
Connecting some components may not be sensible or components may require further configuration to make the connection work correctly. Refer to the linked documentation for more details.
