Add options to scrips and option no_scripts to images

- global: this scritps will be used by all images
  except with explicit no_scripts declaration
- number: add this prefix to the script name

cloud-build.py

@@ -301,9 +301,18 @@ Dir::Etc::preferencesparts "/var/empty";
 
     def scripts_by_image(self, image: str) -> Dict[str, str]:
         scripts = {}
-        for name, contents in self._scripts.items():
-            if name in self._images[image]['scripts']:
-                scripts[name] = contents
+        for name, value in self._scripts.items():
+            number = value.get('number')
+            if (
+                value.get('global', False)
+                and name not in self._images[image].get('no_scripts', [])
+                or name in self._images[image].get('scripts', [])
+            ):
+                if number is not None:
+                    if isinstance(number, int):
+                        number = f'{number:02}'
+                    name = f'{number}-{name}'
+                scripts[name] = value['contents']
         return scripts
 
     def skip_arch(self, image: str, arch: str) -> bool:

example-config.yaml

@@ -28,13 +28,14 @@ images:
     target: ve/docker
     kinds:
     - tar.xz
+    no_scripts:
+    - var
   rootfs-systemd:
     target: ve/systemd-base
     kinds:
     - tar.xz
     scripts:
     - securetty
-    - var
 
 branches:
   Sisyphus:
@@ -67,17 +68,23 @@ branches:
     # - p8
 
 scripts:
-  securetty: |
-    #!/bin/sh
+  securetty:
+    contents: |
+      #!/bin/sh
 
-    echo pts/0 >> /etc/securetty
-  var: |
-    #!/bin/sh
+      echo pts/0 >> /etc/securetty
+    global: no
+    number: 1
+  var:
+    contents: |
+      #!/bin/sh
 
-    for dir in run lock; do
-        mkdir -p "/$dir"
-        mv /var/"$dir"/* "/$dir"
-        rmdir "/var/$dir"
-        ln -sf "/$dir" /var
-    done
+      for dir in run lock; do
+          mkdir -p "/$dir"
+          mv /var/"$dir"/* "/$dir"
+          rmdir "/var/$dir"
+          ln -sf "/$dir" /var
+      done
+    global: yes
+    number: 27
 ...