Bump github.com/lib/pq from 1.10.9 to 1.12.3 (#1349)

lib/pq was pinned at v1.10.9, which was 3 years and 6 releases behind
the latest tag (v1.11.0, v1.11.1, v1.11.2, v1.12.0, v1.12.1, v1.12.3).
Notably, v1.11.0 added support for the target_session_attrs DSN
parameter, which is needed to route connections to a primary/standby
correctly and was the specific ask in #1344.

The only usages of lib/pq in this repo were pq.ParseURL
(exporter/util.go, in parseFingerprint) and pq.Array
(collector/pg_process_idle.go, exporter/namespace.go). pq.ParseURL was
marked deprecated in this range (SA1019), which is the exact breakage
reported in #1284 ("Fix fingerprint generator for new lib/pq").
Rather than suppressing the lint warning, parseFingerprint was
reworked to stop depending on pq.ParseURL: it now uses net/url
directly to pull host/port out of postgres:// and postgresql:// DSNs,
falling back to the existing key=value parser for non-URL DSNs. This
removes the dependency on pq.ParseURL entirely and drops the lib/pq
import from util.go. Behavior is unchanged, verified against the
existing parseFingerprint test cases (URL DSNs, percent-encoded
passwords, key=value DSNs, and the malformed-DSN error path).
pq.Array is unaffected by the bump.

Go version and PostgreSQL version requirements introduced by v1.11.0
(Go 1.21+, PostgreSQL 14+ "supported") are already satisfied by this
module (go 1.25) and CI's oldest tested version (13.22), respectively,
though PG13 is technically past lib/pq's new support window.

Verified with `go build ./...`, `go vet ./...`, `go test ./...`,
golangci-lint (0 issues), govulncheck (0 vulnerabilities), and the
full integration suite (`-tags integration`) against live postgres:13
and postgres:16 Docker containers.

Fixes #1344.
Fixes #1284.

Signed-off-by: Raj <rajeshrajendirandev@gmail.com>

Author: RajeshRajendiran

exporter/util.go

@@ -21,8 +21,6 @@ import (
 	"strconv"
 	"strings"
 	"time"
-
-	"github.com/lib/pq"
 )
 
 // convert a string to the corresponding ColumnUsage
@@ -162,10 +160,27 @@ func dbToString(t interface{}) (string, bool) {
 	}
 }
 
-func parseFingerprint(url string) (string, error) {
-	dsn, err := pq.ParseURL(url)
-	if err != nil {
-		dsn = url
+func parseFingerprint(dsn string) (string, error) {
+	// Only postgres:// and postgresql:// are valid DSN URL schemes; anything
+	// else (e.g. a key=value DSN like "host=example port=1234") falls through
+	// to the key=value parser below.
+	if strings.HasPrefix(dsn, "postgres://") || strings.HasPrefix(dsn, "postgresql://") {
+		u, err := url.Parse(dsn)
+		if err != nil {
+			return "", fmt.Errorf("malformed dsn %q", dsn)
+		}
+
+		host := u.Hostname()
+		if host == "" {
+			host = "localhost"
+		}
+
+		port := u.Port()
+		if port == "" {
+			port = "5432"
+		}
+
+		return host + ":" + port, nil
 	}
 
 	pairs := strings.Split(dsn, " ")
@@ -175,7 +190,6 @@ func parseFingerprint(url string) (string, error) {
 		if len(splitted) != 2 {
 			return "", fmt.Errorf("malformed dsn %q", dsn)
 		}
-		// Newer versions of pq.ParseURL quote values so trim them off if they exist
 		key := strings.Trim(splitted[0], "'\"")
 		value := strings.Trim(splitted[1], "'\"")
 		kv[key] = value

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/DATA-DOG/go-sqlmock v1.5.2
 	github.com/alecthomas/kingpin/v2 v2.4.0
 	github.com/blang/semver/v4 v4.0.0
-	github.com/lib/pq v1.10.9
+	github.com/lib/pq v1.12.3
 	github.com/prometheus/client_golang v1.23.2
 	github.com/prometheus/client_model v0.6.2
 	github.com/prometheus/common v0.69.0

go.sum

@@ -40,8 +40,8 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
 github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
-github.com/lib/pq v1.10.9 h1:YXG7RB+JIjhP29X+OtkiDnYaXQwpS4JEWq7dtCCRUEw=
-github.com/lib/pq v1.10.9/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
+github.com/lib/pq v1.12.3 h1:tTWxr2YLKwIvK90ZXEw8GP7UFHtcbTtty8zsI+YjrfQ=
+github.com/lib/pq v1.12.3/go.mod h1:/p+8NSbOcwzAEI7wiMXFlgydTwcgTr3OSKMsD2BitpA=
 github.com/mdlayher/socket v0.6.0 h1:ScZPaAGyO1icQnbFrhPM8mnXyMu9qukC1K4ZoM2IQKU=
 github.com/mdlayher/socket v0.6.0/go.mod h1:q7vozUAnxSqnjHc12Fik5yUKIzfZ8ITCfMkhOtE9z18=
 github.com/mdlayher/vsock v1.3.0 h1:bqQfZ1OznI03y6YiXp2sze05RVdzLn/zsfjnjd4+ivI=