Break off main function to make module importable

.promu.yml

@@ -3,8 +3,11 @@ go:
     version: 1.16
     cgo: false
 repository:
-    path: github.com/pengbo0328/pgpool2_exporter
+    path: github.com/pgpool/pgpool2_exporter
 build:
+    binaries:
+      - name: pgpool2_exporter
+        path: ./cmd/pgpool2_exporter
     flags: -a -tags 'netgo static_build'
     ldflags: |
         -X github.com/prometheus/common/version.Version={{.Version}}

Makefile

@@ -23,7 +23,7 @@ crossbuild: promu
 promu:
 	@GOOS=$(shell uname -s | tr A-Z a-z) \
 	GOARCH=$(subst x86_64,amd64,$(patsubst i%86,386,$(shell uname -m))) \
-	$(GO) get -u github.com/prometheus/promu
+	$(GO) install github.com/prometheus/promu
 
 tarball: build
 	@echo ">> building release tarball"

cmd/pgpool2_exporter/main.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+
+	"github.com/go-kit/log/level"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"github.com/prometheus/common/promlog"
+	"github.com/prometheus/common/promlog/flag"
+	"github.com/prometheus/common/version"
+	"gopkg.in/alecthomas/kingpin.v2"
+
+	exp "github.com/pgpool/pgpool2_exporter"
+)
+
+func main() {
+	promlogConfig := &promlog.Config{}
+	flag.AddFlags(kingpin.CommandLine, promlogConfig)
+	kingpin.Version(version.Print("pgpool2_exporter"))
+	kingpin.HelpFlag.Short('h')
+	kingpin.Parse()
+
+	exp.Logger = promlog.New(promlogConfig)
+
+	dsn := os.Getenv("DATA_SOURCE_NAME")
+	exporter := exp.NewExporter(dsn, exp.Namespace)
+	defer func() {
+		exporter.DB.Close()
+	}()
+	prometheus.MustRegister(exporter)
+
+	// Retrieve Pgpool-II version
+	v, err := exp.QueryVersion(exporter.DB)
+	if err != nil {
+		level.Error(exp.Logger).Log("err", err)
+	}
+	exp.PgpoolSemver = v
+
+	level.Info(exp.Logger).Log("msg", "Starting pgpool2_exporter", "version", version.Info(), "dsn", exp.MaskPassword(dsn))
+	level.Info(exp.Logger).Log("msg", "Listening on address", "address", *exp.ListenAddress)
+
+	http.Handle(*exp.MetricsPath, promhttp.Handler())
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		w.Write([]byte(fmt.Sprintf(exp.LandingPage, *exp.MetricsPath)))
+	})
+
+	if err := http.ListenAndServe(*exp.ListenAddress, nil); err != nil {
+		level.Error(exp.Logger).Log("err", err)
+		os.Exit(1)
+	}
+}

go.mod

@@ -1,20 +1,39 @@
-module github.com/pengbo0328/pgpool2_exporter
+module github.com/pgpool/pgpool2_exporter
 
-go 1.14
+go 1.17
 
 require (
-	github.com/alecthomas/units v0.0.0-20210208195552-ff826a37aa15 // indirect
 	github.com/blang/semver v3.5.1+incompatible
-	github.com/go-kit/log v0.1.0
+	github.com/go-kit/log v0.2.0
 	github.com/golang/protobuf v1.5.2 // indirect
-	github.com/kr/pretty v0.2.0 // indirect
 	github.com/lib/pq v1.10.2
-	github.com/prometheus/client_golang v1.11.0
-	github.com/prometheus/common v0.29.0
-	github.com/prometheus/procfs v0.7.0 // indirect
+	github.com/prometheus/client_golang v1.12.0
+	github.com/prometheus/common v0.32.1
+	github.com/prometheus/procfs v0.7.3 // indirect
 	github.com/stretchr/testify v1.7.0 // indirect
-	golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c // indirect
+	golang.org/x/sys v0.0.0-20220114195835-da31bd327af9 // indirect
 	google.golang.org/protobuf v1.27.1 // indirect
 	gopkg.in/alecthomas/kingpin.v2 v2.2.6
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b // indirect
 )
+
+require (
+	github.com/Masterminds/semver v1.5.0 // indirect
+	github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751 // indirect
+	github.com/alecthomas/units v0.0.0-20211218093645-b94a6e3cc137 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.1.2 // indirect
+	github.com/go-logfmt/logfmt v0.5.1 // indirect
+	github.com/google/go-cmp v0.5.6 // indirect
+	github.com/google/go-github/v25 v25.1.3 // indirect
+	github.com/google/go-querystring v1.1.0 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/promu v0.13.0 // indirect
+	go.uber.org/atomic v1.9.0 // indirect
+	golang.org/x/net v0.0.0-20220121210141-e204ce36a2ba // indirect
+	golang.org/x/oauth2 v0.0.0-20211104180415-d3ed0bb246c8 // indirect
+	google.golang.org/appengine v1.6.7 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+)