read from config file instead of arguments

.gitignore

@@ -2,3 +2,4 @@ conoha_exporter
 gin-bin
 vendor
 .idea
+conoha_exporter_config.yaml

README.md

@@ -11,21 +11,19 @@ cd conoha_exporter
 go mod download
 
 go build
-./conoha_exporter --help
+./conoha_exporter
 ```
 
 ## usage
 
-```
-Usage of ./conoha_exporter:
-  -password string
-    	ConoHa API user password
-  -port string
-    	Port number to listen on
-  -region string
-    	ConoHa region (default "tyo1")
-  -tenant-id string
-    	ConoHa tenant ID
-  -username string
-    	ConoHa API user name
+Put `conoha_exporter_config.yaml` in the same directory
+
+```yaml
+# Port to listen on
+port: 3030
+# Conoha region
+region: tyo1
+tenant_id: your-tenant-id
+username: conoha-api-username
+password: conoha-api-password
 ```

go.mod

@@ -2,4 +2,7 @@ module github.com/traPtitech/conoha_exporter
 
 go 1.14
 
-require github.com/prometheus/client_golang v1.5.0
+require (
+	github.com/prometheus/client_golang v1.5.0
+	gopkg.in/yaml.v2 v2.2.5
+)

go.sum

@@ -29,8 +29,10 @@ github.com/json-iterator/go v1.1.9/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/u
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
@@ -82,8 +84,10 @@ golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IV
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.5 h1:ymVxjfMaHvXD8RqPRmzHHsB3VvucivSkIAvJFDI5O3c=
 gopkg.in/yaml.v2 v2.2.5/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

main.go

@@ -1,15 +1,22 @@
 package main
 
 import (
-	"flag"
-	"log"
-	"net/http"
-	"os"
-
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"gopkg.in/yaml.v2"
+	"io/ioutil"
+	"log"
+	"net/http"
 )
 
+type Config struct {
+	Port     string `yaml:"port"`
+	Region   string `yaml:"region"`
+	TenantId string `yaml:"tenant_id"`
+	Username string `yaml:"username"`
+	Password string `yaml:"password"`
+}
+
 // インデックスページ用 (Prometheusは別にココを触らないので、お好みで……)
 func indexPage(w http.ResponseWriter, _ *http.Request) {
 	_, _ = w.Write([]byte(`
@@ -29,20 +36,20 @@ func indexPage(w http.ResponseWriter, _ *http.Request) {
 func main() {
 	log.Println("ConoHa exporter started.")
 
-	// コマンドライン引数
-	port := flag.String("port", os.Getenv("PORT"), "Port number to listen on")
-	region := flag.String("region", "tyo1", "ConoHa region")
-	tenantId := flag.String("tenant-id", "", "ConoHa tenant ID")
-	username := flag.String("username", "", "ConoHa API user name")
-	password := flag.String("password", "", "ConoHa API user password")
-	flag.Parse()
+	// config.ymlを読み取る
+	buf, err := ioutil.ReadFile("./conoha_exporter_config.yaml")
+	if err != nil {
+		log.Fatal(err)
+		return
+	}
 
-	if *port == "" {
-		*port = "3000"
+	var config Config
+	if err := yaml.Unmarshal(buf, &config); err != nil {
+		log.Fatal(err)
 	}
 
 	// ConoHa APIクライアントを作成
-	client, err := NewClient(*region, *tenantId, *username, *password)
+	client, err := NewClient(config.Region, config.TenantId, config.Username, config.Password)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -64,5 +71,5 @@ func main() {
 	// HTTPでメトリクスを出力
 	http.HandleFunc("/", indexPage)
 	http.Handle("/metrics", promhttp.Handler())
-	log.Fatal(http.ListenAndServe(":"+*port, nil))
+	log.Fatal(http.ListenAndServe(":"+config.Port, nil))
 }