pgexporter_ext

pgexporter_ext : Operating-system and host metrics for pgexporter

Overview

Packages

Source

pig build pkg pgexporter_ext;		# build rpm/deb

Install

Make sure PGDG and PIGSTY repo available:

pig repo add pgsql -u   # add both repo and update cache

Install this extension with pig:

pig install pgexporter_ext;		# install via package name, for the active PG version

pig install pgexporter_ext -v 18;   # install for PG 18
pig install pgexporter_ext -v 17;   # install for PG 17
pig install pgexporter_ext -v 16;   # install for PG 16
pig install pgexporter_ext -v 15;   # install for PG 15
pig install pgexporter_ext -v 14;   # install for PG 14

Create this extension with:

CREATE EXTENSION pgexporter_ext;

Usage

Sources:

• Version 0.2.5 README
• Version 0.2.5 setup guide
• Version 0.2.5 SQL definitions
• Version 0.2.3 SQL definitions
• Version 0.2.4 SQL definitions
• Version 0.2.5 filesystem implementation

pgexporter_ext exposes Linux host and filesystem metrics through SQL for collection by pgexporter. The examples below apply to the packaged 0.2.3–0.2.5 APIs. Functions run with the PostgreSQL operating-system account’s access, so restrict the monitoring role to trusted users.

Setup and Core Workflow

The upstream setup guide configures the module in shared_preload_libraries, followed by a PostgreSQL restart. Preserve any other libraries already configured.

shared_preload_libraries = 'pgexporter_ext'

In the postgres database, a privileged administrator installs the extension and grants monitoring access to the existing exporter login:

CREATE EXTENSION pgexporter_ext;
GRANT pg_monitor TO pgexporter;

SET ROLE pgexporter;
SELECT pgexporter_version_ext();
SELECT * FROM pgexporter_get_functions();
SELECT * FROM pgexporter_os_info();
SELECT * FROM pgexporter_load_avg();
RESET ROLE;

The SQL scripts revoke public execution and grant it to pg_monitor. That predefined role also grants broad PostgreSQL monitoring access. The release includes a base installation script and an upgrade chain; PostgreSQL can use that chain when installing the default version with CREATE EXTENSION.

Metric Functions

• pgexporter_information_ext() and pgexporter_version_ext() return extension information and version text.
• pgexporter_get_functions() lists metric names, whether they take input, descriptions, and types. pgexporter_is_supported(text) checks a metric name.
• pgexporter_os_info(), pgexporter_cpu_info(), pgexporter_memory_info(), pgexporter_network_info(), and pgexporter_load_avg() return host metrics.
• pgexporter_used_space(text), pgexporter_free_space(text), and pgexporter_total_space(text) return byte counts for a filesystem path.

SELECT pgexporter_is_supported('pgexporter_load_avg');
SELECT pgexporter_free_space('/var/lib/postgresql');

Choose a path that exists on the server and is accessible to its operating-system account. These releases do not provide the later FIPS or log-count APIs.

Operational Boundaries

Filesystem calls use the server’s filesystem view, which may be a container rather than the host. The used-space function walks directories, so large trees can make scrapes expensive. A pg_monitor member can inspect accessible paths; restrict database access and choose collection paths deliberately.

Upstream lists Linux and PostgreSQL 13+; this catalog supplies packages for PostgreSQL 14–18. Use the exact PostgreSQL-major package. The principal RPM supplier is PGDG at 0.2.4 (EL8 PostgreSQL 14–16 use 0.2.3), while Pigsty supplies DEB 0.2.5; enable the Pigsty repository as well when following the cross-platform installation instructions.