Go panic related to postgres-exporter

[victor-smg]

Component(s)

prometheus.exporter.postgres

What's wrong?

There was a bug in postgres-exporter with go panic related to new field coming from postgres database, resolved here

A new release was made 0.19.0 last week, I would like to have alloy use the latest version of postgres-exporter

Alloy is using this fork as reference via a dependency replacement.
I think latest change from upstream in order to have change from the latest release 0.19.0
One need to be a contributor to open PR on the fork. But maybe the existence of the fork itself can be challenge, or alloy could just use the community postgres-exporter

Steps to reproduce

Use postgres cloudsql on GCP on version 18
Run alloy with the following config, with localhost pointing toward cloudsql-proxy

  alloy:
    configMap:
      content: |-
    {{- range $k, $v := .Environment.Values.db }}
        prometheus.exporter.postgres "{{ $v.name }}" {
          data_source_names = ["postgresql://prometheusexporter:{{ $v.pw }}@127.0.0.1:{{ $v.port }}/postgres?sslmode=disable"]
        }

        discovery.relabel "{{ $v.name }}" {
          targets = prometheus.exporter.postgres.{{ $v.name }}.targets

          rule {
            target_label = "instance"
            replacement  = "{{ $k }}"
          }
          rule {
            target_label = "job"
            replacement  = "integrations/postgres_exporter"
          }
        }

System information

No response

Software version

No response

Configuration

alloy:
    configMap:
      content: |-
    {{- range $k, $v := .Environment.Values.db }}
        prometheus.exporter.postgres "{{ $v.name }}" {
          data_source_names = ["postgresql://prometheusexporter:{{ $v.pw }}@127.0.0.1:{{ $v.port }}/postgres?sslmode=disable"]
        }

        discovery.relabel "{{ $v.name }}" {
          targets = prometheus.exporter.postgres.{{ $v.name }}.targets

          rule {
            target_label = "instance"
            replacement  = "{{ $k }}"
          }
          rule {
            target_label = "job"
            replacement  = "integrations/postgres_exporter"
          }
        }

Logs

2026-02-11 10:16:05.357infots=2026-02-11T09:16:05.357610656Z level=info msg="Established new database connection" component_path=/ component_id=prometheus.exporter.postgres.incidents fingerprint=127.0.0.1:5435

2026-02-11 10:16:05.379infots=2026-02-11T09:16:05.379488945Z level=info msg="Semantic version changed" component_path=/ component_id=prometheus.exporter.postgres.incidents server=127.0.0.1:5435 from=0.0.0 to=18.1.0

2026-02-11 10:16:05.386errorpanic: Error converting setting "google_dataplex.max_messages" value "-1:100" to float: strconv.ParseFloat: parsing "-1:100": invalid syntax

2026-02-11 10:16:05.386

2026-02-11 10:16:05.386goroutine 901 [running]:

2026-02-11 10:16:05.386github.com/prometheus-community/postgres_exporter/cmd/postgres_exporter.(*pgSetting).metric(0xc001901400, 0xc00266d320)

2026-02-11 10:16:05.386	/go/pkg/mod/github.com/grafana/postgres_exporter@v0.15.1-0.20250312140329-3046b223bba0/cmd/postgres_exporter/pg_setting.go:86 +0x306

2026-02-11 10:16:05.386github.com/prometheus-community/postgres_exporter/cmd/postgres_exporter.querySettings(0xc000968000, 0xc000c2f8c0)

2026-02-11 10:16:05.386	/go/pkg/mod/github.com/grafana/postgres_exporter@v0.15.1-0.20250312140329-3046b223bba0/cmd/postgres_exporter/pg_setting.go:55 +0x1d8

2026-02-11 10:16:05.386github.com/prometheus-community/postgres_exporter/cmd/postgres_exporter.(*Server).Scrape(0xc000c2f8c0, 0xc000968000, 0xc0?)

2026-02-11 10:16:05.386	/go/pkg/mod/github.com/grafana/postgres_exporter@v0.15.1-0.20250312140329-3046b223bba0/cmd/postgres_exporter/server.go:130 +0xc5

2026-02-11 10:16:05.386github.com/prometheus-community/postgres_exporter/cmd/postgres_exporter.(*Exporter).scrapeDSN(0xc000be2e00, 0xc000968000, {0xc0010f5321, 0x5c})

2026-02-11 10:16:05.386	/go/pkg/mod/github.com/grafana/postgres_exporter@v0.15.1-0.20250312140329-3046b223bba0/cmd/postgres_exporter/datasource.go:114 +0x135

2026-02-11 10:16:05.386github.com/prometheus-community/postgres_exporter/cmd/postgres_exporter.(*Exporter).scrape(0xc000be2e00, 0xc000968000)

2026-02-11 10:16:05.386	/go/pkg/mod/github.com/grafana/postgres_exporter@v0.15.1-0.20250312140329-3046b223bba0/cmd/postgres_exporter/postgres_exporter.go:699 +0x14f

2026-02-11 10:16:05.386github.com/prometheus-community/postgres_exporter/cmd/postgres_exporter.(*Exporter).Collect(0xc000be2e00, 0xc000968000)

2026-02-11 10:16:05.386	/go/pkg/mod/github.com/grafana/postgres_exporter@v0.15.1-0.20250312140329-3046b223bba0/cmd/postgres_exporter/postgres_exporter.go:588 +0x25

2026-02-11 10:16:05.386github.com/prometheus/client_golang/prometheus.(*Registry).Gather.func1()

2026-02-11 10:16:05.386	/go/pkg/mod/github.com/prometheus/client_golang@v1.22.0/prometheus/registry.go:458 +0xe5

2026-02-11 10:16:05.386created by github.com/prometheus/client_golang/prometheus.(*Registry).Gather in goroutine 732

2026-02-11 10:16:05.386	/go/pkg/mod/github.com/prometheus/client_golang@v1.22.0/prometheus/registry.go:548 +0xbf1

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