Add PNIN as a system manifest parameter.

Fixes: andsens#349

Adds a new boolean parameter indicating weather to use PNIN or not to
the system section of the manifest.

The default, False enables tasks for extlinux and grub to pass
net.ifnames=0 biosdevnames=0 parameters to the kernel.

Previously for grub PNIN was disabled for stretch and later. This
remains the default but setting system.pnin True will allow the behavior
to be overridden. The additional parameters have no effect on earlier
releases are passed regardless. Extlinux had no prior special behavior,
it now mirrors grub.

bootstrapvz/base/manifest-schema.yml

@@ -59,6 +59,7 @@ properties:
         type: string
         pattern: ^\S+$
       locale: {type: string}
+      pnin: {type: boolean}
       release: {type: string}
       timezone: {type: string}
     required:

bootstrapvz/common/task_groups.py

@@ -161,6 +161,7 @@ def get_bootloader_group(manifest):
     from bootstrapvz.common.releases import jessie
     from bootstrapvz.common.releases import stretch
     group = []
+    pnin = manifest.system.get('pnin', None)
     if manifest.system['bootloader'] == 'grub':
         group.extend([grub.AddGrubPackage,
                       grub.InitGrubConfig,
@@ -173,7 +174,7 @@ def get_bootloader_group(manifest):
             group.append(grub.InstallGrub_1_99)
         else:
             group.append(grub.InstallGrub_2)
-        if manifest.release >= stretch:
+        if pnin is False or (pnin is None and manifest.release >= stretch):
             group.append(grub.DisablePNIN)
     if manifest.system['bootloader'] == 'extlinux':
         group.append(extlinux.AddExtlinuxPackage)
@@ -183,6 +184,8 @@ def get_bootloader_group(manifest):
         else:
             group.extend([extlinux.ConfigureExtlinuxJessie,
                           extlinux.InstallExtlinuxJessie])
+            if pnin is False or (pnin is None and manifest.release >= stretch):
+                group.append(extlinux.DisablePNIN)
     return group
 
 

bootstrapvz/common/tasks/extlinux.py

@@ -31,6 +31,19 @@ def run(cls, info):
                             r'EXTLINUX_PARAMETERS="\1 console=ttyS0"')
 
 
+class DisablePNIN(Task):
+    description = 'Disabling Predictable Network Interfaces'
+    phase = phases.system_modification
+    predecessors = [filesystem.FStab]
+
+    @classmethod
+    def run(cls, info):
+        from bootstrapvz.common.tools import sed_i
+        extlinux_def = os.path.join(info.root, 'etc/default/extlinux')
+        sed_i(extlinux_def, r'^EXTLINUX_PARAMETERS="([^"]+)"$',
+                            r'EXTLINUX_PARAMETERS="\1 net.ifnames=0 biosdevname=0"')
+
+
 class InstallExtlinux(Task):
     description = 'Installing extlinux'
     phase = phases.system_modification

manifests/README.rst

@@ -162,6 +162,11 @@ system and does not fit under any other section.
 -  ``locale``: The default locale of the system.
    Valid values: Any locale mentioned in ``/etc/locale.gen``
    ``required``
+-  ``pnin``: Enable Persistent Network Interface Naming in the bootloader.
+   Only supported with the ``grub`` and ``extlinux`` bootloaders.
+   Valid values: ``true``, ``false``
+   Default: ``false``
+   ``optional``
 -  ``release``: Defines which debian release should be bootstrapped.
    Valid values: ``wheezy``, ``jessie``, ``stretch``, ``sid``,
    ``oldstable``, ``stable``, ``testing``, ``unstable``