Generic instance macro

See merge request nexedi/slapos!1177

component/macros/virtual-env.cfg

@@ -4,11 +4,12 @@ extends =
 
 [virtual-env-base]
 recipe = slapos.recipe.build
-_name = ${:_buildout_section_name_}
+name = ${:_buildout_section_name_}
+default-instance = true
 init =
   from zc.buildout.easy_install import working_set
   import os
-  name = options['_name']
+  name = options['name']
   eggs = options['eggs']
   try:
     scripts = "scripts = " + options['scripts']
@@ -25,6 +26,26 @@ init =
   <= python-interpreter
   eggs += %(eggs)s
   """ % locals())
+
+  if is_true(options.get('default-instance')):
+    cookbook = "{slapos-cookbook:recipe}"
+    self.buildout.parse("""
+    [.%(name)s.instance]
+    recipe = slapos.recipe.template
+    output = ${buildout:directory}/instance.cfg
+    depends = $%(cookbook)s
+    inline =
+      [buildout]
+      parts = publish
+
+      eggs-directory = ${buildout:eggs-directory}
+      develop-eggs-directory = ${buildout:develop-eggs-directory}
+
+      [publish]
+      recipe = slapos.cookbook:publish
+      activate-script = %(location)s
+    """ % locals())
+
 install =
   with open(location, "w") as f:
     f.write(options['template'] % {

software/django-dev/software.cfg

@@ -4,30 +4,15 @@ extends =
         ../../component/macros/virtual-env.cfg
 
 parts =
-  instance
-  slapos-cookbook
-
-[python]
-part = python3
+        django-env
 
 [django-env]
 <= virtual-env-base
 location = ${buildout:directory}/activate
 eggs = Django
 
-[instance]
-recipe = slapos.recipe.template
-output = ${buildout:directory}/instance.cfg
-inline =
-  [buildout]
-  parts = publish
-
-  eggs-directory = ${buildout:eggs-directory}
-  develop-eggs-directory = ${buildout:develop-eggs-directory}
-
-  [publish]
-  recipe = slapos.cookbook:publish
-  activate-script = ${django-env:location}
+[python]
+part = python3
 
 [versions]
 Django = 3.2.12