Fix hardcoded localhost:8000 URLs

- Add backend/utils.py for URL management
- Update serializers to use normalize_file_url()
- Update views to use URL utils from env vars
- Fix frontend components to use NEXT_PUBLIC_API_URL
- Add new env vars: DJANGO_BACKEND_URL, DJANGO_MEDIA_BASE_URL
- Replace all hardcoded localhost:8000 with configurable URLs

backend/api/serializers.py

@@ -3,6 +3,7 @@ from rest_framework import serializers
 from django.contrib.auth import get_user_model
 from .models import Link, LinkGroup
 from django.conf import settings
+from backend.utils import build_media_url, normalize_file_url
 from .models import Link, LinkGroup
 User = get_user_model()
 
@@ -39,12 +40,8 @@ class UserSerializer(serializers.ModelSerializer):
             request = self.context.get('request')
             if request:
                 absolute_uri = request.build_absolute_uri(obj.avatar.url)
-                # Заменяем различные варианты внутренних Docker URL
-                absolute_uri = absolute_uri.replace('http://web:8000', 'http://localhost:8000')
-                absolute_uri = absolute_uri.replace('http://links-web-1:8000', 'http://localhost:8000')
-                absolute_uri = absolute_uri.replace('http://backend:8000', 'http://localhost:8000')
-                return absolute_uri
-            return f'http://localhost:8000{obj.avatar.url}'
+                return normalize_file_url(absolute_uri)
+            return build_media_url(obj.avatar.url)
         return None
 
 
@@ -71,12 +68,8 @@ class LinkGroupSerializer(serializers.ModelSerializer):
             request = self.context.get('request')
             if request:
                 absolute_uri = request.build_absolute_uri(obj.icon.url)
-                # Заменяем различные варианты внутренних Docker URL
-                absolute_uri = absolute_uri.replace('http://web:8000', 'http://localhost:8000')
-                absolute_uri = absolute_uri.replace('http://links-web-1:8000', 'http://localhost:8000')
-                absolute_uri = absolute_uri.replace('http://backend:8000', 'http://localhost:8000')
-                return absolute_uri
-            return f'http://localhost:8000{obj.icon.url}'
+                return normalize_file_url(absolute_uri)
+            return build_media_url(obj.icon.url)
         return None
 
     def get_background_image_url(self, obj):
@@ -85,12 +78,8 @@ class LinkGroupSerializer(serializers.ModelSerializer):
             request = self.context.get('request')
             if request:
                 absolute_uri = request.build_absolute_uri(obj.background_image.url)
-                # Заменяем различные варианты внутренних Docker URL
-                absolute_uri = absolute_uri.replace('http://web:8000', 'http://localhost:8000')
-                absolute_uri = absolute_uri.replace('http://links-web-1:8000', 'http://localhost:8000')
-                absolute_uri = absolute_uri.replace('http://backend:8000', 'http://localhost:8000')
-                return absolute_uri
-            return f'http://localhost:8000{obj.background_image.url}'
+                return normalize_file_url(absolute_uri)
+            return build_media_url(obj.background_image.url)
         return None
 
     def validate_header_color(self, value):
@@ -126,10 +115,6 @@ class LinkSerializer(serializers.ModelSerializer):
             request = self.context.get('request')
             if request:
                 absolute_uri = request.build_absolute_uri(obj.icon.url)
-                # Заменяем различные варианты внутренних Docker URL
-                absolute_uri = absolute_uri.replace('http://web:8000', 'http://localhost:8000')
-                absolute_uri = absolute_uri.replace('http://links-web-1:8000', 'http://localhost:8000')
-                absolute_uri = absolute_uri.replace('http://backend:8000', 'http://localhost:8000')
-                return absolute_uri
-            return f'http://localhost:8000{obj.icon.url}'
+                return normalize_file_url(absolute_uri)
+            return build_media_url(obj.icon.url)
         return None