add example for dbstatscollector

examples/dbstatscollectorexample/main.go

@@ -0,0 +1,64 @@
+// Copyright 2022 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// A minimal example of how to include Prometheus instrumentation for database stats.
+package main
+
+import (
+	"database/sql"
+	"flag"
+	"fmt"
+	"log"
+	"net/http"
+	"time"
+
+	_ "github.com/mattn/go-sqlite3"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/collectors"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+var addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")
+
+func main() {
+	flag.Parse()
+
+	// Set up an in-memory SQLite DB.
+	db, err := sql.Open("sqlite3", ":memory:") // In-memory SQLite database
+	if err != nil {
+		log.Fatalf("Failed to connect to in-memory database: %v", err)
+	}
+	defer db.Close()
+
+	// Set connection pool limits to simulate more activity.
+	db.SetMaxOpenConns(10)
+	db.SetMaxIdleConns(5)
+	db.SetConnMaxIdleTime(5 * time.Minute)
+	db.SetConnMaxLifetime(30 * time.Minute)
+
+	// Create a new Prometheus registry.
+	reg := prometheus.NewRegistry()
+
+	// Create and register the DB stats collector.
+	dbStatsCollector := collectors.NewDBStatsCollector(db, "sqlite_in_memory")
+	reg.MustRegister(dbStatsCollector)
+
+	// Expose the registered metrics via HTTP.
+	http.Handle("/metrics", promhttp.HandlerFor(
+		reg,
+		promhttp.HandlerOpts{},
+	))
+
+	fmt.Println("Server is running, metrics are available at /metrics")
+	log.Fatal(http.ListenAndServe(*addr, nil))
+}

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/json-iterator/go v1.1.12
 	github.com/klauspost/compress v1.17.10
 	github.com/kylelemons/godebug v1.1.0
+	github.com/mattn/go-sqlite3 v1.14.24
 	github.com/prometheus/client_model v0.6.1
 	github.com/prometheus/common v0.59.1
 	github.com/prometheus/procfs v0.15.1

go.sum

@@ -21,6 +21,8 @@ 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/mattn/go-sqlite3 v1.14.24 h1:tpSp2G2KyMnnQu99ngJ47EIkWVmliIizyZBfPrBWDRM=
+github.com/mattn/go-sqlite3 v1.14.24/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd h1:TRLaZ9cD/w8PVh93nsPXa1VrQ6jlwL5oN8l14QlcNfg=
 github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=