whatismyip/internal/setting/app.go

107 lines
2.7 KiB
Go

package setting
import (
"bytes"
"errors"
"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
version bool
}
const defaultAddress = ":8080"
// ErrVersion is the custom error triggered when -version flag is passed
var ErrVersion = errors.New("setting: version requested")
// App is the var with the parsed settings
var App = settings{
// hard-coded for the time being
Server: serverSettings{
ReadTimeout: 10 * time.Second,
WriteTimeout: 10 * time.Second,
},
}
// Setup initializes the App object parsing the flags
func Setup(args []string) (output string, err error) {
flags := flag.NewFlagSet("whatismyip", flag.ContinueOnError)
var buf bytes.Buffer
flags.SetOutput(&buf)
flags.StringVar(&App.GeodbPath.City, "geoip2-city", "", "Path to GeoIP2 city database")
flags.StringVar(&App.GeodbPath.ASN, "geoip2-asn", "", "Path to GeoIP2 ASN database")
flags.StringVar(&App.TemplatePath, "template", "", "Path to template file")
flags.StringVar(
&App.BindAddress,
"bind",
defaultAddress,
"Listening address (see https://pkg.go.dev/net?#Listen)",
)
flags.StringVar(
&App.TLSAddress,
"tls-bind",
"",
"Listening address for TLS (see https://pkg.go.dev/net?#Listen)",
)
flags.StringVar(&App.TLSCrtPath, "tls-crt", "", "When using TLS, path to certificate file")
flags.StringVar(&App.TLSKeyPath, "tls-key", "", "When using TLS, path to private key file")
flags.StringVar(&App.TrustedHeader,
"trusted-header",
"",
"Trusted request header for remote IP (e.g. X-Real-IP)",
)
flags.BoolVar(&App.version, "version", false, "Output version information and exit")
err = flags.Parse(args)
if err != nil {
return buf.String(), err
}
if App.version {
return fmt.Sprintf("whatismyip version %s", core.Version), ErrVersion
}
if App.GeodbPath.City == "" || App.GeodbPath.ASN == "" {
return "", fmt.Errorf("geoip2-city and geoip2-asn parameters are mandatory")
}
if (App.TLSAddress != "") && (App.TLSCrtPath == "" || App.TLSKeyPath == "") {
return "", fmt.Errorf("In order to use TLS -tls-crt and -tls-key flags are mandatory")
}
if App.TemplatePath != "" {
info, err := os.Stat(App.TemplatePath)
if os.IsNotExist(err) {
return "", fmt.Errorf("%s no such file or directory", App.TemplatePath)
}
if info.IsDir() {
return "", fmt.Errorf("%s must be a file", App.TemplatePath)
}
}
return buf.String(), nil
}