first commit

internal/setting/app.go

@@ -0,0 +1,87 @@
+package setting
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/dcarrillo/whatismyip/internal/core"
+)
+
+type geodbPath struct {
+	City string
+	ASN  string
+}
+type serverSettings struct {
+	ReadTimeout  time.Duration
+	WriteTimeout time.Duration
+}
+type settings struct {
+	GeodbPath     geodbPath
+	TemplatePath  string
+	BindAddress   string
+	TLSAddress    string
+	TLSCrtPath    string
+	TLSKeyPath    string
+	TrustedHeader string
+	Server        serverSettings
+}
+
+const defaultAddress = ":8080"
+
+var App *settings
+
+func Setup() {
+	city := flag.String("geoip2-city", "", "Path to GeoIP2 city database")
+	asn := flag.String("geoip2-asn", "", "Path to GeoIP2 ASN database")
+	template := flag.String("template", "", "Path to template file")
+	address := flag.String("bind", defaultAddress, "Listening address (see https://pkg.go.dev/net?#Listen)")
+	addressTLS := flag.String("tls-bind", "", "Listening address for TLS (see https://pkg.go.dev/net?#Listen)")
+	tlsCrtPath := flag.String("tls-crt", "", "When using TLS, path to certificate file")
+	tlsKeyPath := flag.String("tls-key", "", "When using TLS, path to private key file")
+	trustedHeader := flag.String("trusted-header", "", "Trusted request header for remote IP (e.g. X-Real-IP)")
+	ver := flag.Bool("version", false, "Output version information and exit")
+
+	flag.Parse()
+
+	if *ver {
+		fmt.Printf("whaismyip version %s", core.Version)
+		os.Exit(0)
+	}
+
+	if *city == "" || *asn == "" {
+		exitWithError("geoip2-city and geoip2-asn parameters are mandatory")
+	}
+
+	if (*addressTLS != "") && (*tlsCrtPath == "" || *tlsKeyPath == "") {
+		exitWithError("In order to use TLS -tls-crt and -tls-key flags are mandatory")
+	}
+
+	if *template != "" {
+		info, err := os.Stat(*template)
+		if os.IsNotExist(err) || info.IsDir() {
+			exitWithError(*template + " doesn't exist or it's not a file")
+		}
+	}
+
+	App = &settings{
+		GeodbPath:     geodbPath{City: *city, ASN: *asn},
+		TemplatePath:  *template,
+		BindAddress:   *address,
+		TLSAddress:    *addressTLS,
+		TLSCrtPath:    *tlsCrtPath,
+		TLSKeyPath:    *tlsKeyPath,
+		TrustedHeader: *trustedHeader,
+		Server: serverSettings{
+			ReadTimeout:  10 * time.Second,
+			WriteTimeout: 10 * time.Second,
+		},
+	}
+}
+
+func exitWithError(error string) {
+	fmt.Printf("%s\n\n", error)
+	flag.Usage()
+	os.Exit(1)
+}