IP_STATUS_FILE and routing improvements (#130)

- Obtains VPN public IP address from routing table
- Logs and writes VPN Public IP address to `/ip` as soon as VPN is up
- Obtain port forward, logs it and writes it as soon as VPN is up
- Routing fully refactored and tested
- Routing reads from `/proc/net/route`
- Routing mutates the routes using `ip route ...`

internal/settings/system.go

@@ -4,14 +4,16 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/qdm12/private-internet-access-docker/internal/models"
 	"github.com/qdm12/private-internet-access-docker/internal/params"
 )
 
 // System contains settings to configure system related elements
 type System struct {
-	UID      int
-	GID      int
-	Timezone string
+	UID              int
+	GID              int
+	Timezone         string
+	IPStatusFilepath models.Filepath
 }
 
 // GetSystemSettings obtains the System settings using the params functions
@@ -28,6 +30,10 @@ func GetSystemSettings(params params.ParamsReader) (settings System, err error)
 	if err != nil {
 		return settings, err
 	}
+	settings.IPStatusFilepath, err = params.GetIPStatusFilepath()
+	if err != nil {
+		return settings, err
+	}
 	return settings, nil
 }
 
@@ -37,6 +43,7 @@ func (s *System) String() string {
 		fmt.Sprintf("User ID: %d", s.UID),
 		fmt.Sprintf("Group ID: %d", s.GID),
 		fmt.Sprintf("Timezone: %s", s.Timezone),
+		fmt.Sprintf("IP Status filepath: %s", s.IPStatusFilepath),
 	}
 	return strings.Join(settingsList, "\n|--")
 }