examples: Add Version Collector example

Signed-off-by: Arthur Silva Sens <arthur.sens@coralogix.com>

examples/versioncollector/main.go

@@ -0,0 +1,51 @@
+// 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.
+
+//go:build go1.17
+// +build go1.17
+
+// A minimal example of how to include Prometheus instrumentation.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/collectors/version"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+var addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")
+
+// Build using ldflags:
+// go build -ldflags "-X github.com/prometheus/common/verion.Version=1.0.0 -X github.com/prometheus/common/verion.Branch=abc123" .
+func main() {
+	flag.Parse()
+
+	// Create a new registry.
+	reg := prometheus.NewRegistry()
+
+	// Register version collector.
+	reg.MustRegister(version.NewCollector("example"))
+
+	// Expose the registered metrics via HTTP.
+	http.Handle("/metrics", promhttp.HandlerFor(
+		reg,
+		promhttp.HandlerOpts{},
+	))
+	fmt.Println("Hello world from new Version Collector!")
+	log.Fatal(http.ListenAndServe(*addr, nil))
+}