diff --git a/bundles/left4dead2/items.py b/bundles/left4dead2/items.py
index 29c55da..5652df6 100644
--- a/bundles/left4dead2/items.py
+++ b/bundles/left4dead2/items.py
@@ -9,6 +9,9 @@ directories = {
     '/opt/l4d2': {
         'owner': 'steam', 'group': 'steam',
     },
+    '/opt/l4d2/steam': {
+        'owner': 'steam', 'group': 'steam',
+    },
     '/opt/l4d2/configs': {
         'owner': 'steam', 'group': 'steam',
     },
@@ -31,7 +34,7 @@ files = {
         'mode': '755',
         'triggers': {
             f'svc_systemd:left4dead2-{server_name}.service:restart'
-                for server_name in node.metadata.get('left4dead2').keys()
+                for server_name in node.metadata.get('left4dead2/servers').keys()
         },
     },
     '/opt/l4d2/scripts/helpers': {
@@ -43,7 +46,7 @@ files = {
     },
 }
 
-for overlay in ['vanilla', 'tickrate', 'competitive_rework', 'l4d2center_maps']:
+for overlay in node.metadata.get('left4dead2/overlays'):
     files[f'/opt/l4d2/scripts/overlays/{overlay}'] = {
         'source': f'scripts/overlays/{overlay}',
         'mode': '755',
@@ -63,7 +66,7 @@ svc_systemd = {
     },
 }
 
-for server_name, config in node.metadata.get('left4dead2').items():
+for server_name, config in node.metadata.get('left4dead2/servers').items():
     files[f'/opt/l4d2/configs/{server_name}.cfg'] = {
         'source': 'server.cfg',
         'content_type': 'mako',
diff --git a/bundles/left4dead2/metadata.py b/bundles/left4dead2/metadata.py
index c6a9a44..9f92c9f 100644
--- a/bundles/left4dead2/metadata.py
+++ b/bundles/left4dead2/metadata.py
@@ -1,4 +1,5 @@
 from re import match
+from os import path, listdir
 
 
 defaults = {
@@ -10,7 +11,18 @@ defaults = {
             'p7zip-full': {}, # l4d2center_maps_sync.sh
         },
     },
-    'left4dead2': {},
+    'left4dead2': {
+        'overlays': set(listdir(path.join(repo.path, 'bundles/left4dead2/files/scripts/overlays'))),
+        'servers': {
+            # 'port': 27017,
+            # 'overlays': ['competitive_rework'],
+            # 'arguments': ['-tickrate 60'],
+            # 'config': [
+            #     'exec server_original.cfg',
+            #     'sm_forcematch zonemod',
+            # ],
+        },
+    },
     'nftables': {
         'input': {
             'udp dport { 27005, 27020 } accept',
@@ -45,9 +57,11 @@ defaults = {
 def server_units(metadata):
     units = {}
 
-    for name, config in metadata.get('left4dead2').items():
+    for name, config in metadata.get('left4dead2/servers').items():
         assert match(r'^[A-z0-9-_-]+$', name)
         assert 27000 <= config["port"] <= 27100
+        for overlay in config.get('overlays', []):
+            assert overlay in metadata.get('left4dead2/overlays'), f"unknown overlay {overlay}, known: {metadata.get('left4dead2/overlays')}"
 
         cmd = f'/opt/l4d2/start -n {name} -p {config["port"]}'
 
@@ -95,7 +109,7 @@ def server_units(metadata):
     'nftables/input',
 )
 def nftables(metadata):
-    ports = sorted(str(config["port"]) for config in metadata.get('left4dead2', {}).values())
+    ports = sorted(str(config["port"]) for config in metadata.get('left4dead2/servers').values())
 
     return {
         'nftables': {
diff --git a/nodes/ovh.secondary.py b/nodes/ovh.secondary.py
index 8e16a9b..5317cd4 100644
--- a/nodes/ovh.secondary.py
+++ b/nodes/ovh.secondary.py
@@ -27,30 +27,32 @@
             },
         },
         'left4dead2': {
-            'vanilla': {
-                'port': 27015,
-                'overlays': ['vanilla'],
-            },
-            'tick100': {
-                'port': 27016,
-                'overlays': ['vanilla', 'tickrate'],
-                'arguments': ['-tickrate 100'],
-                'config': [
-                    'exec server_original.cfg',
-                    'sv_minupdaterate 100',
-                    'sv_maxupdaterate 100',
-                    'sv_mincmdrate 100',
-                    'sv_maxcmdrate 100',
-                ],
-            },
-            'server3_comp1': {
-                'port': 27017,
-                'overlays': ['competitive_rework'],
-                'arguments': ['-tickrate 60'],
-                'config': [
-                    'exec server_original.cfg',
-                    'sm_forcematch zonemod',
-                ],
+            'servers': {
+                'vanilla': {
+                    'port': 27015,
+                    'overlays': ['vanilla'],
+                },
+                'tick100': {
+                    'port': 27016,
+                    'overlays': ['vanilla', 'tickrate'],
+                    'arguments': ['-tickrate 100'],
+                    'config': [
+                        'exec server_original.cfg',
+                        'sv_minupdaterate 100',
+                        'sv_maxupdaterate 100',
+                        'sv_mincmdrate 100',
+                        'sv_maxcmdrate 100',
+                    ],
+                },
+                'server3_comp1': {
+                    'port': 27017,
+                    'overlays': ['competitive_rework'],
+                    'arguments': ['-tickrate 60'],
+                    'config': [
+                        'exec server_original.cfg',
+                        'sm_forcematch zonemod',
+                    ],
+                },
             },
         },
         'bind': {
diff --git a/requirements.txt b/requirements.txt
index 75cb897..2e81c9c 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-bundlewrap ~=4.0, >=4.17.2
+bundlewrap ~=4.0, >=4.23.1
 pycryptodome
 PyNaCl
 PyYAML