Metrics

• Add pgBackRest version metric and collector.pgbackrest flag #114:
  • Add pgbackrest_version_info metric to expose pgBackRest version;
  • Add --collector.pgbackrest flag to enable/disable pgBackRest info collector.
    When disabled (--no-collector.pgbackrest), only pgbackrest_version_info and pgbackrest_exporter_build_info metrics are collected.
  • Add new env variable in Dockerfile: COLLECTOR_PGBACKREST - enable pgBackRest collector.

Other

• Refactor multiple parameters with BackrestExporterConfig struct #112.
• Bump dependencies to fix Dependabot alert #113.
• Bump default pgBackRest version to v2.57.0 #115.

Full Changelog: v0.21.0...v0.22.0