Public IP getter loop refactored

internal/params/publicip.go

@@ -3,6 +3,7 @@ package params
 import (
 	"time"
 
+	"github.com/qdm12/gluetun/internal/models"
 	libparams "github.com/qdm12/golibs/params"
 )
 
@@ -15,3 +16,13 @@ func (r *reader) GetPublicIPPeriod() (period time.Duration, err error) {
 	}
 	return time.ParseDuration(s)
 }
+
+// GetPublicIPFilepath obtains the public IP filepath
+// from the environment variable PUBLICIP_FILE with retro-compatible
+// environment variable IP_STATUS_FILE.
+func (r *reader) GetPublicIPFilepath() (filepath models.Filepath, err error) {
+	filepathStr, err := r.envParams.GetPath("PUBLICIP_FILE",
+		libparams.RetroKeys([]string{"IP_STATUS_FILE"}, r.onRetroActive),
+		libparams.Default("/tmp/gluetun/ip"), libparams.CaseSensitiveValue())
+	return models.Filepath(filepathStr), err
+}