V2 alpha - initial version (#172)

Initial alpha codebase for version 2 of WireGuard Portal.
This version is considered unstable and incomplete (for example, no public REST API)! 
Use with care!


Fixes/Implements the following issues:
 - OAuth support #154, #1 
 - New Web UI with internationalisation support #98, #107, #89, #62
 - Postgres Support #49 
 - Improved Email handling #47, #119 
 - DNS Search Domain support #46 
 - Bugfixes #94, #48 

---------

Co-authored-by: Fabian Wechselberger <wechselbergerf@hotmail.com>

internal/adapters/wgquick.go

@@ -0,0 +1,99 @@
+package adapters
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/h44z/wg-portal/internal"
+	"github.com/h44z/wg-portal/internal/domain"
+	"github.com/sirupsen/logrus"
+	"os/exec"
+	"strings"
+)
+
+// WgQuickRepo implements higher level wg-quick like interactions like setting DNS, routing tables or interface hooks.
+type WgQuickRepo struct {
+	shellCmd              string
+	resolvConfIfacePrefix string
+}
+
+func NewWgQuickRepo() *WgQuickRepo {
+	return &WgQuickRepo{
+		shellCmd:              "bash",
+		resolvConfIfacePrefix: "tun.",
+	}
+}
+
+func (r *WgQuickRepo) ExecuteInterfaceHook(id domain.InterfaceIdentifier, hookCmd string) error {
+	if hookCmd == "" {
+		return nil
+	}
+
+	err := r.exec(hookCmd, id)
+	if err != nil {
+		return fmt.Errorf("failed to exec hook: %w", err)
+	}
+
+	return nil
+}
+
+func (r *WgQuickRepo) SetDNS(id domain.InterfaceIdentifier, dnsStr, dnsSearchStr string) error {
+	if dnsStr == "" && dnsSearchStr == "" {
+		return nil
+	}
+
+	dnsServers := internal.SliceString(dnsStr)
+	dnsSearchDomains := internal.SliceString(dnsSearchStr)
+
+	dnsCommand := "resolvconf -a %resPref%i -m 0 -x"
+	dnsCommandInput := make([]string, 0, len(dnsServers)+len(dnsSearchDomains))
+
+	for _, dnsServer := range dnsServers {
+		dnsCommandInput = append(dnsCommandInput, fmt.Sprintf("nameserver %s", dnsServer))
+	}
+	for _, searchDomain := range dnsSearchDomains {
+		dnsCommandInput = append(dnsCommandInput, fmt.Sprintf("search %s", searchDomain))
+	}
+
+	err := r.exec(dnsCommand, id, dnsCommandInput...)
+	if err != nil {
+		return fmt.Errorf("failed to set dns settings: %w", err)
+	}
+
+	return nil
+}
+
+func (r *WgQuickRepo) UnsetDNS(id domain.InterfaceIdentifier) error {
+	dnsCommand := "resolvconf -d %resPref%i -f"
+
+	err := r.exec(dnsCommand, id)
+	if err != nil {
+		return fmt.Errorf("failed to unset dns settings: %w", err)
+	}
+
+	return nil
+}
+
+func (r *WgQuickRepo) replaceCommandPlaceHolders(command string, interfaceId domain.InterfaceIdentifier) string {
+	command = strings.ReplaceAll(command, "%resPref", r.resolvConfIfacePrefix)
+	return strings.ReplaceAll(command, "%i", string(interfaceId))
+}
+
+func (r *WgQuickRepo) exec(command string, interfaceId domain.InterfaceIdentifier, stdin ...string) error {
+	commandWithInterfaceName := r.replaceCommandPlaceHolders(command, interfaceId)
+	cmd := exec.Command(r.shellCmd, "-ce", commandWithInterfaceName)
+	if len(stdin) > 0 {
+		b := &bytes.Buffer{}
+		for _, ln := range stdin {
+			if _, err := fmt.Fprint(b, ln); err != nil {
+				return err
+			}
+		}
+		cmd.Stdin = b
+	}
+	out, err := cmd.CombinedOutput() // execute and wait for output
+	if err != nil {
+		return fmt.Errorf("failed to exexute shell command %s: %w", commandWithInterfaceName, err)
+	}
+	logrus.Tracef("executed shell command %s, with output: %s", commandWithInterfaceName, string(out))
+	return nil
+}