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Reference

Components reference

prometheus.exporter.postgres

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prometheus.exporter.postgres

The prometheus.exporter.postgres component embeds postgres_exporter for collecting metrics from a postgres database.

Multiple prometheus.exporter.postgres components can be specified by giving them different labels.

Usage

prometheus.exporter.postgres "LABEL" {
    data_source_names = DATA_SOURCE_NAMES_LIST
}

Arguments

The following arguments are supported:

Name	Type	Description	Default	Required
`data_source_names`	`list(secret)`	Specifies the Postgres server(s) to connect to.		yes
`disable_settings_metrics`	`bool`	Disables collection of metrics from pg_settings.	`false`	no
`disable_default_metrics`	`bool`	When `true`, only exposes metrics supplied from `custom_queries_config_path`.	`false`	no
`custom_queries_config_path`	`string`	Path to YAML file containing custom queries to expose as metrics.	""	no

The format for connection strings in data_source_names can be found in the official postgresql documentation.

See examples for the custom_queries_config_path file in the postgres_exporter repository.

NOTE: There are a number of environment variables that are not recommended for use, as they will affect all prometheus.exporter.postgres components. A full list can be found in the postgres_exporter repository.

Blocks

The following blocks are supported:

Hierarchy	Block	Description	Required
autodiscovery	autodiscovery	Database discovery settings.	no

autodiscovery block

The autodiscovery block configures discovery of databases, outside of any specified in data_source_names.

The following arguments are supported:

Name	Type	Description	Default	Required
`enabled`	`bool`	Whether to autodiscover other databases	`false`	no
`database_allowlist`	`list(string)`	List of databases to filter for, meaning only these databases will be scraped.		no
`database_denylist`	`list(string)`	List of databases to filter out, meaning all other databases will be scraped.		no

If enabled is set to true and no allowlist or denylist is specified, the exporter will scrape from all databases.

If autodiscovery is disabled, neither database_allowlist nor database_denylist will have any effect.

Exported fields

The following fields are exported and can be referenced by other components.

Name	Type	Description
`targets`	`list(map(string))`	The targets that can be used to collect exporter metrics.

For example, the targets can either be passed to a discovery.relabel component to rewrite the targets’ label sets or to a prometheus.scrape component that collects the exposed metrics.

The exported targets use the configured in-memory traffic address specified by the run command.

Component health

prometheus.exporter.postgres is only reported as unhealthy if given an invalid configuration.

Debug information

prometheus.exporter.postgres does not expose any component-specific debug information.

Debug metrics

prometheus.exporter.postgres does not expose any component-specific debug metrics.

Examples

Collect metrics from a PostgreSQL server

This example uses a prometheus.exporter.postgres component to collect metrics from a Postgres server running locally with all default settings:

// Because no autodiscovery is defined, this will only scrape the 'database_name' database, as defined
// in the DSN below.
prometheus.exporter.postgres "example" {
  data_source_names = ["postgresql://username:password@localhost:5432/database_name?sslmode=disable"]
}

prometheus.scrape "default" {
  targets    = prometheus.exporter.postgres.example.targets
  forward_to = [prometheus.remote_write.demo.receiver]
}

prometheus.remote_write "demo" {
  endpoint {
    url = PROMETHEUS_REMOTE_WRITE_URL

    basic_auth {
      username = USERNAME
      password = PASSWORD
    }
  }
}

Replace the following:

PROMETHEUS_REMOTE_WRITE_URL: The URL of the Prometheus remote_write-compatible server to send metrics to.
USERNAME: The username to use for authentication to the remote_write API.
PASSWORD: The password to use for authentication to the remote_write API.

Collect custom metrics from an allowlisted set of databases

This example uses a prometheus.exporter.postgres component to collect custom metrics from a set of specific databases, replacing default metrics with custom metrics derived from queries in /etc/agent/custom-postgres-metrics.yaml:

prometheus.exporter.postgres "example" {
  data_source_names = ["postgresql://username:password@localhost:5432/database_name?sslmode=disable"]

  // This block configures autodiscovery to check for databases outside of the 'database_name' db
  // specified in the DSN above. The database_allowlist field means that only the 'frontend_app' and 'backend_app'
  // databases will be scraped.
  autodiscovery {
    enabled            = true
    database_allowlist = ["frontend_app", "backend_app"]
  }

  disable_default_metrics    = true
  custom_queries_config_path = "/etc/agent/custom-postgres-metrics.yaml"
}

prometheus.scrape "default" {
  targets    = prometheus.exporter.postgres.example.targets
  forward_to = [prometheus.remote_write.demo.receiver]
}

prometheus.remote_write "demo" {
  endpoint {
    url = PROMETHEUS_REMOTE_WRITE_URL

    basic_auth {
      username = USERNAME
      password = PASSWORD
    }
  }
}

Replace the following:

PROMETHEUS_REMOTE_WRITE_URL: The URL of the Prometheus remote_write-compatible server to send metrics to.
USERNAME: The username to use for authentication to the remote_write API.
PASSWORD: The password to use for authentication to the remote_write API.

Collect metrics from all databases except for a denylisted database

This example uses a prometheus.exporter.postgres component to collect custom metrics from all databases except for the secrets database.

prometheus.exporter.postgres "example" {
  data_source_names = ["postgresql://username:password@localhost:5432/database_name?sslmode=disable"]

  // The database_denylist field will filter out those databases from the list of databases to scrape,
  // meaning that all databases *except* these will be scraped.
  //
  // In this example it will scrape all databases except for the one named 'secrets'.
  autodiscovery {
    enabled           = true
    database_denylist = ["secrets"]
  }
}

prometheus.scrape "default" {
  targets    = prometheus.exporter.postgres.example.targets
  forward_to = [prometheus.remote_write.demo.receiver]
}

prometheus.remote_write "demo" {
  endpoint {
    url = PROMETHEUS_REMOTE_WRITE_URL

    basic_auth {
      username = USERNAME
      password = PASSWORD
    }
  }
}

Replace the following:

PROMETHEUS_REMOTE_WRITE_URL: The URL of the Prometheus remote_write-compatible server to send metrics to.
USERNAME: The username to use for authentication to the remote_write API.
PASSWORD: The password to use for authentication to the remote_write API.