[iOS] Add force relay connection on iOS (#4928)

* [ios] Add a bogus test to check iOS behavior when setting environment variables

* [ios] Revert "Add a bogus test to check iOS behavior when setting environment variables"

This reverts commit 90ca01105a6b0f4471aac07a63fc95e5d4eaef9b.

* [ios] Add EnvList struct to export and import environment variables

* [ios] Add envList parameter to the iOS Client Run method

* [ios] Add some debug logging to exportEnvVarList

* Add "//go:build ios" to client/ios/NetBirdSDK files

client/ios/NetBirdSDK/client.go

@@ -1,9 +1,12 @@
+//go:build ios
+
 package NetBirdSDK
 
 import (
 	"context"
 	"fmt"
 	"net/netip"
+	"os"
 	"sort"
 	"strings"
 	"sync"
@@ -90,7 +93,8 @@ func NewClient(cfgFile, stateFile, deviceName string, osVersion string, osName s
 }
 
 // Run start the internal client. It is a blocker function
-func (c *Client) Run(fd int32, interfaceName string) error {
+func (c *Client) Run(fd int32, interfaceName string, envList *EnvList) error {
+	exportEnvList(envList)
 	log.Infof("Starting NetBird client")
 	log.Debugf("Tunnel uses interface: %s", interfaceName)
 	cfg, err := profilemanager.UpdateOrCreateConfig(profilemanager.ConfigInput{
@@ -433,3 +437,19 @@ func toNetIDs(routes []string) []route.NetID {
 	}
 	return netIDs
 }
+
+func exportEnvList(list *EnvList) {
+	if list == nil {
+		return
+	}
+	for k, v := range list.AllItems() {
+		log.Debugf("Env variable %s's value is currently: %s", k, os.Getenv(k))
+		log.Debugf("Setting env variable %s: %s", k, v)
+
+		if err := os.Setenv(k, v); err != nil {
+			log.Errorf("could not set env variable %s: %v", k, err)
+		} else {
+			log.Debugf("Env variable %s was set successfully", k)
+		}
+	}
+}

client/ios/NetBirdSDK/env_list.go

@@ -0,0 +1,34 @@
+//go:build ios
+
+package NetBirdSDK
+
+import "github.com/netbirdio/netbird/client/internal/peer"
+
+// EnvList is an exported struct to be bound by gomobile
+type EnvList struct {
+	data map[string]string
+}
+
+// NewEnvList creates a new EnvList
+func NewEnvList() *EnvList {
+	return &EnvList{data: make(map[string]string)}
+}
+
+// Put adds a key-value pair
+func (el *EnvList) Put(key, value string) {
+	el.data[key] = value
+}
+
+// Get retrieves a value by key
+func (el *EnvList) Get(key string) string {
+	return el.data[key]
+}
+
+func (el *EnvList) AllItems() map[string]string {
+	return el.data
+}
+
+// GetEnvKeyNBForceRelay Exports the environment variable for the iOS client
+func GetEnvKeyNBForceRelay() string {
+	return peer.EnvKeyNBForceRelay
+}

client/ios/NetBirdSDK/gomobile.go

@@ -1,3 +1,5 @@
+//go:build ios
+
 package NetBirdSDK
 
 import _ "golang.org/x/mobile/bind"

client/ios/NetBirdSDK/logger.go

@@ -1,3 +1,5 @@
+//go:build ios
+
 package NetBirdSDK
 
 import (

client/ios/NetBirdSDK/login.go

@@ -1,3 +1,5 @@
+//go:build ios
+
 package NetBirdSDK
 
 import (

client/ios/NetBirdSDK/peer_notifier.go

@@ -1,3 +1,5 @@
+//go:build ios
+
 package NetBirdSDK
 
 // PeerInfo describe information about the peers. It designed for the UI usage

client/ios/NetBirdSDK/preferences.go

@@ -1,3 +1,5 @@
+//go:build ios
+
 package NetBirdSDK
 
 import (

client/ios/NetBirdSDK/preferences_test.go

@@ -1,3 +1,5 @@
+//go:build ios
+
 package NetBirdSDK
 
 import (

client/ios/NetBirdSDK/routes.go

@@ -1,3 +1,5 @@
+//go:build ios
+
 package NetBirdSDK
 
 // RoutesSelectionInfoCollection made for Java layer to get non default types as collection