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Prometheus Exporter

Status Available in: core, contrib Maintainers: @Aneurysm9, @dashpole, @ArthurSens Source: opentelemetry-collector-contrib

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Supported Telemetry

Metrics

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Overview

Exports data in the Prometheus format, which allows it to be scraped by a Prometheus server.

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Getting Started

The following settings are required: The following settings can be optionally configured:
  • const_labels (no default): key/values that are applied for every exported metric.
  • namespace (no default): if set, exports metrics under the provided value.
  • send_timestamps (default = false): if true, sends the timestamp of the underlying metric sample in the response.
  • metric_expiration (default = 5m): defines how long metrics are exposed without updates
  • resource_to_telemetry_conversion
    • enabled (default = false): If enabled is true, all the resource attributes will be converted to metric labels by default.
  • enable_open_metrics: (default = false): If true, metrics will be exported using the OpenMetrics format. Exemplars are only exported in the OpenMetrics format, and only for histogram and monotonic sum (i.e. counter) metrics.
  • without_scope_info: (default = false): If true, metrics will be exported without scope name, version, schemaURL, and attributes encoded as labels.
  • add_metric_suffixes: (default = true): If false, addition of type and unit suffixes is disabled. Deprecated: Use translation_strategy instead. This setting is ignored when translation_strategy is explicitly set.
  • translation_strategy: Controls how OTLP metric and attribute names are translated into Prometheus metric and label names. When set, this takes precedence over add_metric_suffixes. Available options:
    • UnderscoreEscapingWithSuffixes: Fully escapes metric names for classic Prometheus metric name compatibility, and includes appending type and unit suffixes.
    • UnderscoreEscapingWithoutSuffixes: Metric names will continue to escape special characters to _, but suffixes won’t be attached.
    • NoUTF8EscapingWithSuffixes: Disables changing special characters to _. Special suffixes like units and _total for counters will be attached.
    • NoTranslation: Bypasses all metric and label name translation, passing them through unaltered.
Example: 
exporters:
  prometheus:
    endpoint: "1.2.3.4:1234"
    tls:
      ca_file: "/path/to/ca.pem"
      cert_file: "/path/to/cert.pem"
      key_file: "/path/to/key.pem"
    namespace: test-space
    const_labels:
      label1: value1
      "another label": spaced value
    send_timestamps: true
    metric_expiration: 180m
    enable_open_metrics: true
    # Legacy configuration - deprecated, ignored when translation_strategy is set
    add_metric_suffixes: false
    translation_strategy: "UnderscoreEscapingWithoutSuffixes"
    resource_to_telemetry_conversion:
      enabled: true
Given the example, metrics will be available at https://1.2.3.4:1234/metrics.

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Feature gates

There are also flags that control translation behavior. See the documentation for the Prometheus translator module for more information.

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Metric names and labels normalization

By Default, OpenTelemetry metric names and attributes are normalized to be compliant with Prometheus naming rules. Optionally, users can set different translation_strategy options to control how metrics are exposed. Please be aware that Prometheus itself uses content negotiation to decide how to ingest metrics, and underscore escaping might be applied even though this exporter is configured to keep UTF-8 characters. For more details, read Prometheus’ Content Negotiation documentation.

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Setting resource attributes as metric labels

By default, resource attributes are added to a special metric called target_info. To select and group by metrics by resource attributes, you need to do join on target_info. For example, to select metrics with k8s_namespace_name attribute equal to my-namespace: 
app_ads_ad_requests_total * on (job, instance) group_left target_info{k8s_namespace_name="my-namespace"}
Or to group by a particular attribute (for ex. k8s_namespace_name): 
sum by (k8s_namespace_name) (app_ads_ad_requests_total * on (job, instance) group_left(k8s_namespace_name) target_info)
This is not a common pattern, and we recommend copying the most common resource attributes into metric labels. You can do this through the transform processor: 
processor:
  transform:
    metric_statements:
      - context: datapoint
        statements:
        - set(attributes["namespace"], resource.attributes["k8s.namespace.name"])
        - set(attributes["container"], resource.attributes["k8s.container.name"])
        - set(attributes["pod"], resource.attributes["k8s.pod.name"])
After this, grouping or selecting becomes as simple as: 
app_ads_ad_requests_total{namespace="my-namespace"}

sum by (namespace) (app_ads_ad_requests_total)

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Configuration

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Example Configuration

prometheus:
prometheus/2:
  endpoint: "1.2.3.4:1234"
  tls:
    ca_file: "certs/ca.crt"
    key_file: "certs/server.key"
    cert_file: "certs/server.crt"
  namespace: test-space
  const_labels:
    label1: value1
    "another label": spaced value
  send_timestamps: true
  metric_expiration: 60m
  add_metric_suffixes: false
Last generated: 2026-04-13